WorldWideScience

Sample records for preliminary thermal deformation

  1. Thermal-mechanical deformation modelling of soft tissues for thermal ablation.

    Science.gov (United States)

    Li, Xin; Zhong, Yongmin; Jazar, Reza; Subic, Aleksandar

    2014-01-01

    Modeling of thermal-induced mechanical behaviors of soft tissues is of great importance for thermal ablation. This paper presents a method by integrating the heating process with thermal-induced mechanical deformations of soft tissues for simulation and analysis of the thermal ablation process. This method combines bio-heat transfer theories, constitutive elastic material law under thermal loads as well as non-rigid motion dynamics to predict and analyze thermal-mechanical deformations of soft tissues. The 3D governing equations of thermal-mechanical soft tissue deformation are discretized by using the finite difference scheme and are subsequently solved by numerical algorithms. Experimental results show that the proposed method can effectively predict the thermal-induced mechanical behaviors of soft tissues, and can be used for the thermal ablation therapy to effectively control the delivered heat energy for cancer treatment.

  2. Effect of preliminary plastic deformation on low temperature strength of carbon steels

    International Nuclear Information System (INIS)

    Gur'ev, A.V.; Alkhimenkov, T.B.

    1979-01-01

    Considered is the effect of preliminary plastic deformation on the following low-temperature strength (at -196 deg C) of structural carbon steels at the room temperature. The study of regularities of microheterogenetic deformations by alloy structure elements at room and low temperatures shows that the transition on low -temperature loading is built on the base of inheritance of the general mechanism of plastic deformation, which took place at preliminary deformation; in this effect the ''memory'' of metal to the history of loading is shown. It is established that physical strengthening (cold hardening), received by the metal during preliminary loading at the room temperature is put over the strengthening connected only with decrease of test temperature

  3. The thermal and mechanical deformation study of up-stream pumping mechanical seal

    International Nuclear Information System (INIS)

    Chen, H L; Xu, C; Zuo, M Z; Wu, Q B

    2015-01-01

    Taking the viscosity-temperature relationship of the fluid film into consideration, a 3-D numerical model was established by ANSYS software which can simulate the heat transfer between the upstream pumping mechanical seal stationary and rotational rings and the fluid film between them as well as simulate the thermal deformation, structure deformation and the coupling deformation of them. According to the calculation result, thermal deformation causes the seal face expansion and the maximum thermal deformation appears at the inside of the seal ring. Pressure results in a mechanical deformation, the maximum deformation occurs at the top of the spiral groove and the overall trend is inward the mating face, opposite to the thermal deformation. The coupling deformation indicate that the thermal deformation can be partly counteracted by pressure deformation. Using this model, the relationship between deformation and shaft speed and the sealing liquid pressure was studied. It's found that the shaft speed will both enhance the thermal and structure deformation and the fluid pressure will enhance the structure deformation but has little to do with the thermal deformation. By changing the sealing material, it's found that material with low thermal expansion coefficient and low elastic modulus will suffer less thermal-pressure deformation

  4. The thermal and mechanical deformation study of up-stream pumping mechanical seal

    Science.gov (United States)

    Chen, H. L.; Xu, C.; Zuo, M. Z.; Wu, Q. B.

    2015-01-01

    Taking the viscosity-temperature relationship of the fluid film into consideration, a 3-D numerical model was established by ANSYS software which can simulate the heat transfer between the upstream pumping mechanical seal stationary and rotational rings and the fluid film between them as well as simulate the thermal deformation, structure deformation and the coupling deformation of them. According to the calculation result, thermal deformation causes the seal face expansion and the maximum thermal deformation appears at the inside of the seal ring. Pressure results in a mechanical deformation, the maximum deformation occurs at the top of the spiral groove and the overall trend is inward the mating face, opposite to the thermal deformation. The coupling deformation indicate that the thermal deformation can be partly counteracted by pressure deformation. Using this model, the relationship between deformation and shaft speed and the sealing liquid pressure was studied. It's found that the shaft speed will both enhance the thermal and structure deformation and the fluid pressure will enhance the structure deformation but has little to do with the thermal deformation. By changing the sealing material, it's found that material with low thermal expansion coefficient and low elastic modulus will suffer less thermal-pressure deformation.

  5. Practical Calculation of Thermal Deformation and Manufacture Error uin Surface Grinding

    Institute of Scientific and Technical Information of China (English)

    周里群; 李玉平

    2002-01-01

    The paper submits a method to calculate thermal deformation and manufacture error in surface grinding.The author established a simplified temperature field model.and derived the thermal deformaiton of the ground workpiece,It is found that there exists not only a upwarp thermal deformation,but also a parallel expansion thermal deformation.A upwarp thermal deformation causes a concave shape error on the profile of the workpiece,and a parallel expansion thermal deformation causes a dimension error in height.The calculations of examples are given and compared with presented experiment data.

  6. Change of mechanical properties of irradiated silicon iron in dependence of preliminary deformation

    International Nuclear Information System (INIS)

    Chirkina, L.A.; Okovit, V.S.; Khinkis, B.A.

    1979-01-01

    Presented are the data on the influence of the 225 MeV electron irradiation on flow limit and specific elongation of silicon iron specimens preliminary deformed by slipping and twinning. The irradiaton was carried out at the temperature up to 350 K with integral dose up to 7x10 18 el/cm 2 . The specimens were tested in the temperature range of 4-450 K. It is found that the ductile brittle transition temperature Tsub(c) and plastic deformation mode of the irradiated material heavily depends on the preliminary deformation mode. The irradiation of specimens deformed by slipping leads to the increase in transition temperature (Tsub(c)) by 80 deg and it reaches 420 K. The preliminary deformation by twinning results in the Tsub(c) increase up to 320 K

  7. Thermal elastic deformations of the planet Mercury.

    Science.gov (United States)

    Liu, H.-S.

    1972-01-01

    The variation in solar heating due to the resonance rotation of Mercury produces periodic elastic deformations on the surface of the planet. The thermal stress and strain fields under Mercury's surface are calculated after certain simplifications. It is found that deformations penetrate to a greater depth than the variation of solar heating, and that the thermal strain on the surface of the planet pulsates with an amplitude of .004 and a period of 176 days.

  8. Preliminary deformation model for National Seismic Hazard map of Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Meilano, Irwan; Gunawan, Endra; Sarsito, Dina; Prijatna, Kosasih; Abidin, Hasanuddin Z. [Geodesy Research Division, Faculty of Earth Science and Technology, Institute of Technology Bandung (Indonesia); Susilo,; Efendi, Joni [Agency for Geospatial Information (BIG) (Indonesia)

    2015-04-24

    Preliminary deformation model for the Indonesia’s National Seismic Hazard (NSH) map is constructed as the block rotation and strain accumulation function at the elastic half-space. Deformation due to rigid body motion is estimated by rotating six tectonic blocks in Indonesia. The interseismic deformation due to subduction is estimated by assuming coupling on subduction interface while deformation at active fault is calculated by assuming each of the fault‘s segment slips beneath a locking depth or in combination with creeping in a shallower part. This research shows that rigid body motion dominates the deformation pattern with magnitude more than 15 mm/year, except in the narrow area near subduction zones and active faults where significant deformation reach to 25 mm/year.

  9. A thermal comparator sensor for measuring autogenous deformation in hardening Portland cement paste

    DEFF Research Database (Denmark)

    Østergaard, Thomas; Jensen, Ole Mejlhede

    2003-01-01

    This paper describes a simple and accurate experimental device specially developed to measure autogenous deformation in hardening cement-based materials. The measuring system consists of a so-called thermal comparator sensor and a modular thermostatically controlled system. The operating principle...... of the thermal comparator is based on thermal expansion of aluminium. A particular characteristic of the measuring system is the fixation of the thermal comparator sensor to the deforming specimen. The modular system ensures effective thermostatic control of the hydrating cement paste samples. The technique...... allows continuous measurement with high accuracy of the linear deformation as well as determination of the activation energy of autogenous deformation....

  10. Effect of plastic deformation on the niobium thermal expansion

    International Nuclear Information System (INIS)

    Savitskij, E.M.; Bychkova, M.I.; Kanikovskij, V.B.

    1978-01-01

    Using dilatometric method the effect of plastic deformation on change of thermal expansion coefficient (TEC) of niobium of different purity was studied. It was shown that deformation affected the TEC in different ways. At first the deformation degree rising causes linear decrease of the TEC and then linear increase. Carbon intensifies the TEC decrease of deformed niobium. The linear correlation was established between the TEC and the value of macroscopic stresses in plastic deformed niobium. The expression indicating the metal TEC change under loading was defined for case of strain hardening

  11. Interface conductance between roughened Be and steel under thermal deformation

    International Nuclear Information System (INIS)

    Tillack, M.S.; Abelson, R.D.

    1995-01-01

    Predictability and control over temperatures and stresses are necessary in order to assure acceptable tritium release, component reliability and lifetime in solid breeder blankets. These blankets usually contain beryllium multiplier in either pebble-bed or solid block forms. For the solid block forms, uncertainties remain in the prediction of the thermal resistance between the Be and its cladding. Several parameters are important, including surface roughness and flatness, background gas pressure, and external loads which may result from blanket thermal deformations and/or pressure stresses. Differential thermal deformation between Be and steel can cause separation to occur between the two solid surfaces, which could seriously degrade the heat transfer. Existing models and data for solid-solid conductance show inconsistencies, even for steel surfaces. Little data or none exists for the Be-steel system, in which differential surface deformations are expected. In this work, we describe a new model which incorporates the combined influences of thermal deformation and contact pressure. Data were taken with small Be specimens as a function of the relevant parameters. The results show that the inclusion of non-conforming surfaces provides a richer range of behavior. Thermal deformations degrade the heat transfer by about a factor of two from flat surfaces, but this effect tends to decrease above about 100 kW m -2 . Contact pressure (above about 1 MPa) between the two materials can effectively maintain good conductance. The flatness and roughness of the surfaces are the most critical parameters. The work also demonstrates the large degree of variation in conductance with background gas pressure. (orig.)

  12. Numerical analysis of thermal deformation in laser beam heating of a steel plate

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chao; Kim, Yong-Rae; Kim, Jae-Woong [Yeungnam University, Kyongsan (Korea, Republic of)

    2017-05-15

    Line heating is a widely used process for plate forming or thermal straightening. Flame heating and induction heating are the traditional heating processes used by industry for line heating. However, these two heating processes are ineffective when used on small steel plates. Thus, the laser beam heating with various power profiles were carried out in this study. A comparison of numerical simulation results and experimental results found a significant difference in the thermal deformation when apply a different power profile of laser beam heating. The one-sinusoid power profile produced largest thermal deformation in this study. The laser beam heating process was simulated by established a combined heat source model, and simulated results were compared with experimental results to confirm the model’s accuracy. The mechanism of thermal deformation was investigated and the effects of model parameters were studied intensively with the finite element method. Thermal deformation was found to have a significant relationship with the amount of central zone plastic deformation. Scientists and engineers could use this study’s verified model to select appropriate parameters in laser beam heating process. Moreover, by using the developed laser beam model, the analysis of welding residual stress or hardness could also be investigated from a power profile point of view.

  13. Controlling thermal deformation by using composite materials having variable fiber volume fraction

    International Nuclear Information System (INIS)

    Bouremana, M.; Tounsi, A.; Kaci, A.; Mechab, I.

    2009-01-01

    In application, many thin structural components such as beams, plates and shells experience a through-thickness temperature variation. This temperature variation can produce both an in-plane expansion and an out-of-plane (bending) curvature. Given that these thin components interact with or connect to other components, we often wish to minimize the thermal deformation or match the thermal deformation of another component. This is accomplished by using a composite whose fibers have a negative axial thermal expansion coefficient. By varying the fiber volume fraction within a symmetric laminated beam to create a functionally graded material (FGM), certain thermal deformations can be controlled or tailored. Specifically, a beam can be designed which does not curve under a steady-state through-thickness temperature variation. Continuous gradation of the fiber volume fraction in the FGM layer is modelled in the form of a mth power polynomial of the coordinate axis in thickness direction of the beam. The beam results are independent of the actual temperature values, within the limitations of steady-state heat transfer and constant material properties. The influence of volume fiber fraction distributions are studied to match or eliminate an in-plane expansion coefficient, or to match a desired axial stiffness. Combining two fiber types to create a hybrid FGM can offer desirable increase in axial and bending stiffness while still retaining the useful thermal deformation behavior.

  14. Test and analysis of thermal ratcheting deformation for 316L stainless steel cylindrical structure

    International Nuclear Information System (INIS)

    Lee, Hyeong Yeon; Kim, Jong Bum; Lee, Jae Han

    2002-01-01

    In this study, the progressive inelastic deformation, so called, thermal ratchet phenomenon which can occur in high temperature structures of liquid metal simulated with thermal ratchet structural test facility and 316L stainless steel test cylinder. The thermal ratchet deformation at the reactor baffle cylinder of the liquid metal reactor can occur due to the moving temperature distribution along the axial direction as the sodium free surface moves up and down under the cyclic heat-up and cool-down transients. The ratchet deformation was measured with the laser displacement sensor and LVDTs after cooling the structural specimen which is heated up to 550 degree C with steep temperature gradients along the axial direction. The temperature distribution of the test cylinder along the axial direction was measured with 28 channels of thermocouples and was used for the ratchet analysis. The thermal ratchet deformation was analyzed with the constitutive equation of nonlinear combined hardening model which was implemented as ABAQUS user subroutine and the analysis results were compared with those of the test. Thermal ratchet load was applied 9 times and the residual displacement after 9 cycles of thermal load was measured to be 1.79 mm. The ratcheting deformation shapes obtained by the analysis with the combined hardening model were in reasonable agreement with those of the structural tests

  15. Static Aeroelastic Deformation Effects in Preliminary Wind-tunnel Tests of Silent Supersonic Technology Demonstrator

    OpenAIRE

    Makino, Yoshikazu; Ohira, Keisuke; Makimoto, Takuya; Mitomo, Toshiteru; 牧野, 好和; 大平, 啓介; 牧本, 卓也; 三友, 俊輝

    2011-01-01

    Effects of static aeroelastic deformation of a wind-tunnel test model on the aerodynamic characteristics are discussed in wind-tunnel tests in the preliminary design phase of the silent supersonic technology demonstrator (S3TD). The static aeroelastic deformation of the main wing is estimated for JAXA 2m x 2m transonic wind-tunnel and 1m x 1m supersonic wind-tunnel by a finite element method (FEM) structural analysis in which its structural model is tuned with the model deformation calibratio...

  16. Investigations on thermal properties, stress and deformation of Al/SiC metal matrix composite based on finite element method

    Directory of Open Access Journals (Sweden)

    K. A. Ramesh Kumar

    2014-09-01

    Full Text Available AlSiC is a metal matrix composite which comprises of aluminium matrix with silicon carbide particles. It is characterized by high thermal conductivity (180-200 W/m K, and its thermal expansion are attuned to match other important materials that finds enormous demand in industrial sectors. Although its application is very common, the physics behind the Al-SiC formation, functionality and behaviors are intricate owing to the temperature gradient of hundreds of degrees, over the volume, occurring on a time scale of a few seconds, involving multiple phases. In this study, various physical, metallurgical and numerical aspects such as equation of continuum for thermal, stress and deformation using finite element (FE matrix formulation, temperature dependent material properties, are analyzed. Modelling and simulation studies of Al/SiC composites are a preliminary attempt to view this research work from computational point of view.

  17. A new approach to characterize the effect of fabric deformation on thermal protective performance

    International Nuclear Information System (INIS)

    Li, Jun; Li, Xiaohui; Lu, Yehu; Wang, Yunyi

    2012-01-01

    It is very important to evaluate thermal protective performance (TPP) in laboratory-simulated fire scenes as accurately as possible. For this paper, to thoroughly understand the effect of fabric deformation on basic physical properties and TPP of flame-retardant fabrics exposed to flash fire, a new modified TPP testing apparatus was developed. Different extensions were employed to simulate the various extensions displayed during different body motions. The tests were also carried out with different air gaps. The results showed a significant decrease in air permeability after deformation. However, the change of thickness was slight. The fabric deformation had a complicated effect on thermal protection with different air gaps. The change of TPP depended on the balance between the surface contact area and the thermal insulation. The newly developed testing apparatus could be well employed to evaluate the effect of deformation on TPP of flame-resistant fabrics. (paper)

  18. A new approach to characterize the effect of fabric deformation on thermal protective performance

    Science.gov (United States)

    Li, Jun; Li, Xiaohui; Lu, Yehu; Wang, Yunyi

    2012-04-01

    It is very important to evaluate thermal protective performance (TPP) in laboratory-simulated fire scenes as accurately as possible. For this paper, to thoroughly understand the effect of fabric deformation on basic physical properties and TPP of flame-retardant fabrics exposed to flash fire, a new modified TPP testing apparatus was developed. Different extensions were employed to simulate the various extensions displayed during different body motions. The tests were also carried out with different air gaps. The results showed a significant decrease in air permeability after deformation. However, the change of thickness was slight. The fabric deformation had a complicated effect on thermal protection with different air gaps. The change of TPP depended on the balance between the surface contact area and the thermal insulation. The newly developed testing apparatus could be well employed to evaluate the effect of deformation on TPP of flame-resistant fabrics.

  19. Experience base for Radioactive Waste Thermal Processing Systems: A preliminary survey

    International Nuclear Information System (INIS)

    Mayberry, J.; Geimer, R.; Gillins, R.; Steverson, E.M.; Dalton, D.; Anderson, G.L.

    1992-04-01

    In the process of considering thermal technologies for potential treatment of the Idaho National Engineering Laboratory mixed transuranic contaminated wastes, a preliminary survey of the experience base available from Radioactive Waste Thermal Processing Systems is reported. A list of known commercial radioactive waste facilities in the United States and some international thermal treatment facilities are provided. Survey focus is upon the US Department of Energy thermal treatment facilities. A brief facility description and a preliminary summary of facility status, and problems experienced is provided for a selected subset of the DOE facilities

  20. Experimental Study on Hygrothermal Deformation of External Thermal Insulation Cladding Systems with Glazed Hollow Bead

    Directory of Open Access Journals (Sweden)

    Houren Xiong

    2016-01-01

    Full Text Available This research analyzes the thermal and strain behavior of external thermal insulation cladding systems (ETICS with Glazed Hollow Beads (GHB thermal insulation mortar under hygrothermal cycles weather test in order to measure its durability under extreme weather (i.e., sunlight and rain. Thermometers and strain gauges are placed into different wall layers to gather thermal and strain data and another instrument measures the crack dimensions after every 4 cycles. The results showed that the finishing coat shrank at early stage (elastic deformation and then the finishing coat tends to expand and become damaged at later stage (plastic deformation. The deformation of insulation layer is similar to that of the finishing coat but its variation amplitude is smaller. Deformation of substrate expanded with heat and contracted with cold due to the small temperature variation. The length and width of cracks on the finishing coat grew as the experiment progressed but with a decreasing growth rate and the cracks stopped growing around 70 cycles.

  1. Understanding thermally activated plastic deformation behavior of Zircaloy-4

    Science.gov (United States)

    Kumar, N.; Alomari, A.; Murty, K. L.

    2018-06-01

    Understanding micromechanics of plastic deformation of existing materials is essential for improving their properties further and/or developing advanced materials for much more severe load bearing applications. The objective of the present work was to understand micromechanics of plastic deformation of Zircaloy-4, a zirconium-based alloy used as fuel cladding and channel (in BWRs) material in nuclear reactors. The Zircaloy-4 in recrystallized (at 973 K for 4 h) condition was subjected to uniaxial tensile testing at a constant cross-head velocity at temperatures in the range 293 K-1073 K and repeated stress relaxation tests at 293 K, 573 K, and 773 K. The minimum in the total elongation was indicative of dynamic strain aging phenomenon in this alloy in the intermediate temperature regime. The yield stress of the alloy was separated into effective and athermal components and the transition from thermally activated dislocation glide to athermal regime took place at around 673 K with the athermal stress estimated to be 115 MPa. The activation volume was found to be in the range of 40 b3 to 160 b3. The activation volume values and the data analyses using the solid-solution models in literature indicated dislocation-solute interaction to be a potential deformation mechanism in thermally activated regime. The activation energy calculated at 573 K was very close to that found for diffusivity of oxygen in α-Zr that was suggestive of dislocations-oxygen interaction during plastic deformation. This type of information may be helpful in alloy design in selecting different elements to control the deformation behavior of the material and impart desired mechanical properties in those materials for specific applications.

  2. Thermal flexural analysis of cross-ply laminated plates using trigonometric shear deformation theory

    Directory of Open Access Journals (Sweden)

    Yuwaraj Marotrao Ghugal

    Full Text Available Thermal stresses and displacements for orthotropic, two-layer antisymmetric, and three-layer symmetric square cross-ply laminated plates subjected to nonlinear thermal load through the thickness of laminated plates are presented by using trigonometric shear deformation theory. The in-plane displacement field uses sinusoidal function in terms of thickness co-ordinate to include the shear deformation effect. The theory satisfies the shear stress free boundary conditions on the top and bottom surfaces of the plate. The present theory obviates the need of shear correction factor. Governing equations and boundary conditions of the theory are obtained using the principle of virtual work. The validity of present theory is verified by comparing the results with those of classical plate theory and first order shear deformation theory and higher order shear deformation theory.

  3. Research on Non-Similarity about Thermal Deformation Error of Mechanical Parts in High-accuracy Measurement

    International Nuclear Information System (INIS)

    Luo, Z; Fei, Y T

    2006-01-01

    Expanding with heat and contracting with cold are common physical phenomenon in the nature. The conventional theories and calculations of thermal deformation are approximate and linear, can only be applied in normal or low precision field. The thermal deformation error of mechanical parts doesn't follow the conventional linear formula, it relates to all physical dimension of the mechanical part, and the deformation can be indicated by a nonlinear formula of physical dimensions. A theory on non-similarity about thermal deformation error of mechanical parts is presented. Studies on some common mechanical parts in precision technology have went on and the mathematical models have been set up, hollow piece, gear and cube are included. The experimental results also make it clear that these models are more logical than traditional models

  4. The Lamb wave bandgap variation of a locally resonant phononic crystal subjected to thermal deformation

    Science.gov (United States)

    Zhu, Yun; Li, Zhen; Li, Yue-ming

    2018-05-01

    A study on dynamical characteristics of a ternary locally resonant phononic crystal (PC) plate (i.e., hard scatterer with soft coating periodically disperse in stiff host matrix) is carried out in this paper. The effect of thermal deformation on the structure stiffness, which plays an important role in the PC's dynamical characteristics, is considered. Results show that both the start and the stop frequency of bandgap shift to higher range with the thermal deformation. In particular, the characteristics of band structure change suddenly at critical buckling temperature. The effect of thermal deformation could be utilized for tuning of phononic band structures, which can promote their design and further applications.

  5. Influence of preliminary deformation and phase strengthening on γ reversible α transformation kinetics in cerium under pressure

    International Nuclear Information System (INIS)

    Larionov, L.V.; Livshits, L.D.; Peresada, G.I.; AN SSSR, Moscow. Inst. Fiziki Zemli)

    1985-01-01

    Using the methods of piezo- and resistometry the influence of preliminary plastic deformation, phase transformation induced strengthening and heat treatment on kinetics of γ reversible α transformation in cerium is studied. It is shown, that the used methods of preliminary treatment of sample material do not change pressure value of γ → α and α →γ transformation initiation and do not affect hysteresis value, but affect considerably its kinetics. Preliminary plastic deformation and structural strengthening increase the average formation rate of a new phase. According to the data of tensile tests, structural strengthening, apprearing as a result of one cycle of γ → α → γ transformation, increases cerium strength characteristics 6y 30-50% with simultaneous decrease in plasticity. Metallographic studies confirm martensitic character of γ → α → γ transformations in cerium

  6. STUDY OF THE EFFECT OF PRELIMINARY PLASTIC DEFORMATION IN THE PROCESS OF DISSOLUTION DURING TEMPERING OF LOW-CARBON AND BORON-CONTAINING ALLOYS

    OpenAIRE

    M. Yu. Filonenko; S. B. Piliaieva

    2009-01-01

    In the paper the influence of preliminary deformation on disintegration of martensite in boron-containing and carbonic alloy is explored. It is shown that at the small degree of deformation (7 per cent) both in low-carbonic and boron-containing alloys the process of martensite disintegration takes place less intensively. The increase of degree of preliminary deformation in a boron-containing alloy is instrumental in more even distribution of boron-cementite particles appearing as a result of ...

  7. STUDY OF THE EFFECT OF PRELIMINARY PLASTIC DEFORMATION IN THE PROCESS OF DISSOLUTION DURING TEMPERING OF LOW-CARBON AND BORON-CONTAINING ALLOYS

    Directory of Open Access Journals (Sweden)

    M. Yu. Filonenko

    2009-12-01

    Full Text Available In the paper the influence of preliminary deformation on disintegration of martensite in boron-containing and carbonic alloy is explored. It is shown that at the small degree of deformation (7 per cent both in low-carbonic and boron-containing alloys the process of martensite disintegration takes place less intensively. The increase of degree of preliminary deformation in a boron-containing alloy is instrumental in more even distribution of boron-cementite particles appearing as a result of martensite disintegration.

  8. Preliminary thermal and stress analysis of the SINQ window

    International Nuclear Information System (INIS)

    Heidenreich, G.

    1991-01-01

    Preliminary results of a finite element analysis for the SINQ proton beam window are presented. Temperatures and stresses are calculated in an axisymmetric model. As a result of these calculations, the H 2 O-cooled window (safety window) could be redesigned in such a way that plastic deformation resulting from excessive stress in some areas is avoided. (author)

  9. Control of thermal deformation in dielectric mirrors using mechanical design and atomic layer deposition.

    Science.gov (United States)

    Gabriel, Nicholas T; Kim, Sangho S; Talghader, Joseph J

    2009-07-01

    A mechanical design technique for optical coatings that simultaneously controls thermal deformation and optical reflectivity is reported. The method requires measurement of the refractive index and thermal stress of single films prior to the design. Atomic layer deposition was used for deposition because of the high repeatability of the film constants. An Al2O3/HfO2 distributed Bragg reflector was deposited with a predicted peak reflectivity of 87.9% at 542.4 nm and predicted edge deformation of -360 nm/K on a 10 cm silicon substrate. The measured peak reflectivity was 85.7% at 541.7 nm with an edge deformation of -346 nm/K.

  10. Preliminary three-dimensional model of mantle convection with deformable, mobile continental lithosphere

    Science.gov (United States)

    Yoshida, Masaki

    2010-06-01

    deformation. From geological evidence that a cratonic root survives at the surface for billions of years, the WCM may have existed in the past supercontinent throughout the Earth's geologic history. The preliminary model presented here should represent an important step toward realizing a more realistic model that could be used to address many outstanding geodynamic problems about the thermal and mechanical feedbacks between the mantle and continents and the temporal evolution of the Earth's mantle structure.

  11. Numerical simulation of time-dependent deformations under hygral and thermal transient conditions

    International Nuclear Information System (INIS)

    Roelfstra, P.E.

    1987-01-01

    Some basic concepts of numerical simulation of the formation of the microstructure of HCP are outlined. The aim is to replace arbitrary terms like aging by more realistic terms like bond density in the xerogel and bonds between hydrating particles of HCP. Actual state parameters such as temperature, humidity and degree of hydration can be determined under transient hygral and thermal conditions by solving numerically a series of appropriate coupled differential equations with given boundary conditions. Shrinkage of a composite structure without crack formation, based on calculated moisture distributions, has been determined with numerical concrete codes. The influence of crack formation, tensile strain-hardening and softening on the total deformation of a quasi-homogeneous drying material has been studied by means of model based on FEM. The difference between shrinkage without crack formation and shrinkage with crack formation can be quantified. Drying shrinkage and creep of concrete cannot be separated. The total deformation depends on the superimposed stress fields. Transient hygral deformation can be realistically predicted if the concept of point properties is applied rigorously. Transient thermal deformation has to be dealt with in the same way. (orig./HP)

  12. Method for compensating bellows pressure loads while accommodating thermal deformations

    International Nuclear Information System (INIS)

    Woodle, M.H.

    1985-01-01

    Many metal bellows are used on storage ring vacuum chambers. They allow the ring to accommodate deformations associated with alignment, mechanical assembly and thermal expansion. The NSLS has two such electron storage rings, the vuv ring and the x-ray ring. Both rings utilize a number of welded metal bellows within the ring and at every beam port. There are provisions for 16 beam ports on the vuv and 28 ports in the x-ray ring. At each of these locations the bellows are acted on by an external pressure of 1 atmosphere, which causes a 520 lb reaction at the vacuum chamber beam port and at the beamline flange downstream of the bellows. The use of rigid tie rods across the bellows flanges to support this load is troublesome because most storage ring vacuum chambers are baked in situ to achieve high internal vacuum. Significant forces can develop on components if thermal deformation is restrained and damage could occur

  13. Thermally induced processes in mixtures of aluminum with organic acids after plastic deformations under high pressure

    Science.gov (United States)

    Zhorin, V. A.; Kiselev, M. R.; Roldugin, V. I.

    2017-11-01

    DSC is used to measure the thermal effects of processes in mixtures of solid organic dibasic acids with powdered aluminum, subjected to plastic deformation under pressures in the range of 0.5-4.0 GPa using an anvil-type high-pressure setup. Analysis of thermograms obtained for the samples after plastic deformation suggests a correlation between the exothermal peaks observed around the temperatures of degradation of the acids and the thermally induced chemical reactions between products of acid degradation and freshly formed surfaces of aluminum particles. The release of heat in the mixtures begins at 30-40°C. The thermal effects in the mixtures of different acids change according to the order of acid reactivity in solutions. The extreme baric dependences of enthalpies of thermal effects are associated with the rearrangement of the electron subsystem of aluminum upon plastic deformation at high pressures.

  14. Effect of Length, Diameter, Chirality, Deformation, and Strain on Contact Thermal Conductance between Single Wall Carbon Nanotubes

    Science.gov (United States)

    Varshney, Vikas; Lee, Jonghoon; Brown, Joshua S.; Farmer, Barry L.; Voevodin, Andrey A.; Roy, Ajit K.

    2018-04-01

    Thermal energy transfer across physically interacting single-wall carbon nanotube (SWCNT) interconnects has been investigated using non-equilibrium molecular dynamics simulations. The role of various geometrical and structural (length, diameter, chirality) as well as external (deformation and strain) carbon nanotube (CNT) parameters has been explored to estimate total as well as area-normalized thermal conductance across cross-contact interconnects. It is shown that the CNT aspect ratio and degree of lateral as well as tensile deformation play a significant role in determining the extent of thermal energy exchange across CNT contacts, while CNT chirality has a negligible influence on thermal transport. Depending on the CNT diameter, aspect ratio, and degree of deformation at the contact interface, the thermal conductance values can vary significantly –by more than an order of magnitude for total conductance and a factor of 3 to 4 for area-normalized conductance. The observed trends are discussed from the perspective of modulation in number of low frequency out-of-plane (transverse, flexural, and radial) phonons that transmit thermal energy across the contact and govern the conductance across the interface. The established general dependencies for phonon governed thermal transport at CNT contacts are anticipated to help design and performance prediction of CNT-based flexible nanoelectronic devices, where CNT-CNT contact deformation and strain are routinely encountered during device operations.

  15. Influence of preliminary deformation on structure and properties of Fe-Ni-V-C alloy after reverse α → γ transformation

    International Nuclear Information System (INIS)

    Izotov, V.I.; Kozlov, A.P.

    1979-01-01

    Using transmission electron microscopy, the Fe-25 Ni-1.5 V-0.3 C alloy structure was investigated after the γ → α → γ transformation and the effect of the preliminary deformation upon it in the range from 16 to 33% at the temperature of +200 and -196 deg C. Characteristic of nondeformed specimens is the lath morphology of the reverse austenite. Deformation prior to the α → γ transformation is conducive to the appearance of areas of fine-grained austenite With a low density of dislocations, probably forming through a partial recrystallization of the lath austenite. It was found that the reverse austenite inherits the misorientation zones which are a structure particularity of slippage-deformed (259) martensite crystals (7). The maximum strength of the alloy after the α → γ transformation is achieved through a preliminary deformation at-196 deg C leading to a decrease in the amount of austenite that failed to undergo the γ → α → γ transformation

  16. Preliminary thermal architecture of the X-IFU instrument dewar

    Science.gov (United States)

    Charles, Ivan; Daniel, Christophe; André, Jérome; Duband, Lionel; Duval, Jean-Marc; den Hartog, Roland; Mitsuda, Kazuhisa; Shinozaki, Keisuke; van Weers, Henk; Yamasaki, Noriko Y.

    2016-07-01

    The ESA Athena mission will implement 2 instruments to study the hot and energetic universe. The X-ray Integral Field Unit (X-IFU) will provide spatially resolved high resolution spectroscopy. This high energy resolution of 2.5 eV at 7 keV could be achieved thanks to TES (Transition Edge Sensor) detectors that need to be cooled to very low temperature. To obtain the required 50 mK temperature level, a careful design of the cryostat and of the cooling chain including different technologies in cascade is needed. The preliminary cryogenic architecture of the X-IFU instrument that fulfils the TES detector thermal requirements is described. In particular, the thermal design of the detector focal plane assembly (FPA), that uses three temperature stages (from 2 K to 50 mK) to limit the thermal loads on the lowest temperature stage, is described. The baseline cooling chain is based on European and Japanese mechanical coolers (Stirling, Pulse tube and Joule Thomson coolers) that precool a sub Kelvin cooler made of a 3He sorption cooler coupled with a small ADR (Adiabatic Demagnetization Refrigerator). Preliminary thermal budgets of the X-IFU cryostat are presented and discussed regarding cooling chain performances.

  17. Influence of preliminary plastic deformation on plasticity characteristics and structure of armco-iron

    International Nuclear Information System (INIS)

    Vergazov, A.N.; Rybin, V.V.; Meshkov, Yu.Ya.; Moskvina, V.A.; Serditova, T.N.

    1990-01-01

    Effect of preliminary plastic deformation (PPD) by drawing on the maximum plasticity characteristics (critical rupture strain) ε c , general δ and uniform δ p relative elongation and on the structure of armco-iron in a wide range of PPD degree change (e=0-4.6) is studied. It is ascertained that with e growth the metal plastic properties at T test =77 and 293 K change in a different way. In particular, the critical strain ε c increases monotonously at 77 K and reduces at 293 K. It is shown that all changes of mechanical characteristics observed with e increase are conditioned by the development of fragmentation process in armco-iron. The data obtained are discussed from the veiwpoint of the developed plastic deformation physics concepts

  18. Plastic deformation tests on fragile materials using a thermal expansion machine

    International Nuclear Information System (INIS)

    Orozco, E.; Morales, A.; Mendoza, A.

    1991-01-01

    Applying an electrical current on an iron bar, a thermal expansion can be induced. We have taken advantage of this to deform fragile materials, in order to study their mechanical properties. In this paper we show some gels and high T c oxide superconductors (Author)

  19. STUDY ON THERMAL DEFORMATIONS OF THE PRIMARY SEALING OF FRONT SEALING

    Directory of Open Access Journals (Sweden)

    Mihaela ISTRATE

    2015-05-01

    Full Text Available The thermal phenomena appear at the level of the film within the primary sealing interstitium. An important temperature gradient is performed in the stator and in the rotor, which produces thermoelastic deformations. These deformations are of the order of film width and affect essentially the interstitium geometry. According to the temperature increase direction the repartition in the friction ring is different. The farthest areas from the temperature drops or the nearest to the heat sources will have he highest temperature. These dilate more that the rest of the areas and modify the interstitium form. From the calculation relations it comes out that deformations depend also on certain operating conditions, which can be modified through time (pressure, temperature, the sealing efficiency being thus different in time.

  20. Shear deformation-induced anisotropic thermal conductivity of graphene.

    Science.gov (United States)

    Cui, Liu; Shi, Sanqiang; Wei, Gaosheng; Du, Xiaoze

    2018-01-03

    Graphene-based materials exhibit intriguing phononic and thermal properties. In this paper, we have investigated the heat conductance in graphene sheets under shear-strain-induced wrinkling deformation, using equilibrium molecular dynamics simulations. A significant orientation dependence of the thermal conductivity of graphene wrinkles (GWs) is observed. The directional dependence of the thermal conductivity of GWs stems from the anisotropy of phonon group velocities as revealed by the G-band broadening of the phonon density of states (DOS), the anisotropy of thermal resistance as evidenced by the G-band peak mismatch of the phonon DOS, and the anisotropy of phonon relaxation times as a direct result of the double-exponential-fitting of the heat current autocorrelation function. By analyzing the relative contributions of different lattice vibrations to the heat flux, we have shown that the contributions of different lattice vibrations to the heat flux of GWs are sensitive to the heat flux direction, which further indicates the orientation-dependent thermal conductivity of GWs. Moreover, we have found that, in the strain range of 0-0.1, the anisotropy ratio of GWs increases monotonously with increasing shear strain. This is induced by the change in the number of wrinkles, which is more influential in the direction perpendicular to the wrinkle texture. The findings elucidated here emphasize the utility of wrinkle engineering for manipulation of nanoscale heat transport, which offers opportunities for the development of thermal channeling devices.

  1. Co-planar deformation and thermal propagation behavior in a bundle burst test

    International Nuclear Information System (INIS)

    Uetsuka, Hiroshi; Koizumi, Yasuo; Kawasaki, Satoru

    1980-07-01

    The probability of the suggested feedback mechanism which could lead to co-planar deformation in a bundle burst test was assessed by the data of test and the calculation based on simplified model. Following four points were evaluated. (1) The probability of local deformation during early heat up stage. (2) The relation between the characteristic of heater and the feedback mechanism. (3) Thermal propagation behavior between two adjacent rods during heat up stage. (4) The propagation of ballooning in a bundle. The probability of suggested feedback mechanism was denied in all the evaluation. The feedback mechanism suggested by Burman could not be a controlling mechanism in co-planar deformation in a bundle burst test. (author)

  2. Monitoring the Deformation of High-Rise Buildings in Shanghai Luijiazui Zone by Tomo-Psinsar

    Science.gov (United States)

    Zhou, L. F.; Ma, P. F.; Xia, Y.; Xie, C. H.

    2018-05-01

    In this study, we utilize a Tomography-based Persistent Scatterers Interferometry (Tomo-PSInSAR) approach for monitoring the deformation performances of high-rise buildings, i.e. SWFC and Jin Mao Tower, in Shanghai Lujiazui Zone. For the purpose of this study, we use 31 Stripmap acquisitions from TerraSAR-X missions, spanning from December 2009 to February 2013. Considering thermal expansion, creep and shrinkage are two long-term movements that occur in high-rise buildings with concrete structures, we use an extended 4-D SAR phase model, and three parameters (height, deformation velocity, and thermal amplitude) are estimated simultaneously. Moreover, we apply a two-tier network strategy to detect single and double PSs with no need for preliminary removal of the atmospheric phase screen (APS) in the study area, avoiding possible error caused by the uncertainty in spatiotemporal filtering. Thermal expansion is illustrated in the thermal amplitude map, and deformation due to creep and shrinkage is revealed in the linear deformation velocity map. The thermal amplitude map demonstrates that the derived thermal amplitude of the two high-rise buildings both dilate and contract periodically, which is highly related to the building height due to the upward accumulative effect of thermal expansion. The linear deformation velocity map reveals that SWFC is subject to deformation during the new built period due to creep and shrinkage, which is height-dependent movements in the linear velocity map. It is worth mention that creep and shrinkage induces movements that increase with the increasing height in the downward direction. In addition, the deformation rates caused by creep and shrinkage are largest at the beginning and gradually decrease, and at last achieve a steady state as time goes infinity. On the contrary, the linear deformation velocity map shows that Jin Mao Tower is almost stable, and the reason is that it is an old built building, which is not influenced by creep

  3. MONITORING THE DEFORMATION OF HIGH-RISE BUILDINGS IN SHANGHAI LUIJIAZUI ZONE BY TOMO-PSINSAR

    Directory of Open Access Journals (Sweden)

    L. F. Zhou

    2018-05-01

    Full Text Available In this study, we utilize a Tomography-based Persistent Scatterers Interferometry (Tomo-PSInSAR approach for monitoring the deformation performances of high-rise buildings, i.e. SWFC and Jin Mao Tower, in Shanghai Lujiazui Zone. For the purpose of this study, we use 31 Stripmap acquisitions from TerraSAR-X missions, spanning from December 2009 to February 2013. Considering thermal expansion, creep and shrinkage are two long-term movements that occur in high-rise buildings with concrete structures, we use an extended 4-D SAR phase model, and three parameters (height, deformation velocity, and thermal amplitude are estimated simultaneously. Moreover, we apply a two-tier network strategy to detect single and double PSs with no need for preliminary removal of the atmospheric phase screen (APS in the study area, avoiding possible error caused by the uncertainty in spatiotemporal filtering. Thermal expansion is illustrated in the thermal amplitude map, and deformation due to creep and shrinkage is revealed in the linear deformation velocity map. The thermal amplitude map demonstrates that the derived thermal amplitude of the two high-rise buildings both dilate and contract periodically, which is highly related to the building height due to the upward accumulative effect of thermal expansion. The linear deformation velocity map reveals that SWFC is subject to deformation during the new built period due to creep and shrinkage, which is height-dependent movements in the linear velocity map. It is worth mention that creep and shrinkage induces movements that increase with the increasing height in the downward direction. In addition, the deformation rates caused by creep and shrinkage are largest at the beginning and gradually decrease, and at last achieve a steady state as time goes infinity. On the contrary, the linear deformation velocity map shows that Jin Mao Tower is almost stable, and the reason is that it is an old built building, which is not

  4. Thermal deformation analysis and test of electron gun for high power klystron

    International Nuclear Information System (INIS)

    Zhou Zusheng; Chinese Academy of Sciences, Beijing; Dong Dong

    2006-01-01

    A 120 MW pulsed electron gun has been developed for 50 MW China-made klystron. It has a Pierce type dispenser cathode and it scans with a diameter of 85 mm. This paper describes the temperature field distribution in the gun and the gun deformation caused by this distribution by using ANSYS. According to the real complex structure and the energy conversion inside the electron gun, the authors took the thermal conduction as the main energy conversion form and got the temperature field. The coincidence between the temperature field and the structural deformation is also described. The beam optics simulated by EGUN with and without considering deformation is discussed, and the valuable results have been obtained. The high power test results and simulation results are analyzed and compared. (authors)

  5. Elasto/visco-plastic deformation of moderately thick shells of revolution under thermal loading due to fluid

    International Nuclear Information System (INIS)

    Takezono, S.; Tao, K.; Aoki, T.; Inamura, E.

    1993-01-01

    This paper is concerned with an analytical formulation and a numerical solution of the thermo-elasto/visco-plastic deformation of general, moderately thick shells of revolution subjected to thermal loads due to fluid. At first the temperature distribution through the thickness is supposed to be curves of second order, and the temperature field in the shell under the appropriate initial and boundary conditions is determined by using the equations of heat conduction and heat transfer. Secondly the stresses and deformations are derived from the thermal stress equations. The equations of equilibrium and the relations between the strains and displacements are developed by extending the Reissner-Naghdi theory for elastic shells. For the constitutive relations, the Perzyna elasto/visco-plastic equations including the temperature effect are employed. The fundamental equations derived are numerically solved by the finite difference method. As a numerical example, the simply supported cylindrical shell made of mild steel under thermal loading due to fluid is analyzed, and the results are compared with those from classical theory which neglects the effect of shear deformations. (author)

  6. Preliminary thermal design of the COLD-SAT spacecraft

    Science.gov (United States)

    Arif, Hugh

    1991-01-01

    The COLD-SAT free-flying spacecraft was to perform experiments with LH2 in the cryogenic fluid management technologies of storage, supply and transfer in reduced gravity. The Phase A preliminary design of the Thermal Control Subsystem (TCS) for the spacecraft exterior and interior surfaces and components of the bus subsystems is described. The TCS was composed of passive elements which were augmented with heaters. Trade studies to minimize the parasitic heat leakage into the cryogen storage tanks are described. Selection procedure for the thermally optimum on-orbit spacecraft attitude was defined. TRASYS-2 and SINDA'85 verification analysis was performed on the design and the results are presented.

  7. Thermal deformation prediction in reticles for extreme ultraviolet lithography based on a measurement-dependent low-order model

    NARCIS (Netherlands)

    Bikcora, C.; Weiland, S.; Coene, W.M.J.

    2014-01-01

    In extreme ultraviolet lithography, imaging errors due to thermal deformation of reticles are becoming progressively intolerable as the source power increases. Despite this trend, such errors can be mitigated by adjusting the wafer and reticle stages based on a set of predicted deformation-induced

  8. Deformation analysis considering thermal expansion of injection mold

    International Nuclear Information System (INIS)

    Kim, Jun Hyung; Yi, Dae Eun; Jang, Jeong Hui; Lee, Min Seok

    2015-01-01

    In the design of injection molds, the temperature distribution and deformation of the mold is one of the most important parameters that affect the flow characteristics, flash generation, and surface appearance, etc. Plastic injection analyses have been carried out to predict the temperature distribution of the mold and the pressure distribution on the cavity surface. As the input loads, we transfer the temperature and pressure results to the structural analysis. We compare the structural analysis results with the thermal expansion effect using the actual flash and step size of a smartphone cover part. To reduce the flash problem, we proposed a new mold design, and verified the results by performing simulations

  9. Deformation analysis considering thermal expansion of injection mold

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun Hyung; Yi, Dae Eun; Jang, Jeong Hui; Lee, Min Seok [Samsung Electronics Co., LTD., Seoul (Korea, Republic of)

    2015-09-15

    In the design of injection molds, the temperature distribution and deformation of the mold is one of the most important parameters that affect the flow characteristics, flash generation, and surface appearance, etc. Plastic injection analyses have been carried out to predict the temperature distribution of the mold and the pressure distribution on the cavity surface. As the input loads, we transfer the temperature and pressure results to the structural analysis. We compare the structural analysis results with the thermal expansion effect using the actual flash and step size of a smartphone cover part. To reduce the flash problem, we proposed a new mold design, and verified the results by performing simulations.

  10. Coupling analysis of deformation and thermal-hydraulics in a FBR fuel pin bundle using BAMBOO and ASFRE-IV Codes

    International Nuclear Information System (INIS)

    Ito, Masahiro; Imai, Yasutomo; Uwaba, Tomoyuki; Ohshima, Hiroyuki

    2004-03-01

    The bundle-duct interaction may occur in sodium cooled wire-wrapped FBR fuel subassemblies in high burn-up conditions. JNC has been developing a bundle deformation analysis code BAMBOO (Behavior Analysis code for Mechanical interaction of fuel Bundle under On-power Operation), a thermal hydraulics analysis code ASFRE-IV (Analysis of Sodium Flow in Reactor Elements - ver. IV) and their coupling method as a simulation system for the evaluation on the integrity of deformed FBR fuel pin bundles. In this study, the simulation system was applied to a coupling analysis of deformation and thermal-hydraulics in the fuel pin-bundle under a steady-state condition just after startup for the purpose of the verification of the simulation system. The iterative calculations of deformation and thermal-hydraulics employed in the coupling analysis provided numerically unstable solutions. From the result, it was found that improvement of the coupling algorithm of BAMBOO and ASFRE-IV is necessary to reduce numerical fluctuations and to obtain better convergence by introducing such computational technique as the optimized under-relaxation method. (author)

  11. A pratical case of a pipeline deformation by transverse and longitudinal thermal gradient

    International Nuclear Information System (INIS)

    Franca Filho, J.L. de; Souza, H.S.; Ribeiro, S.V.G.

    1982-01-01

    A pratical case of pipeline deformation due to a thermal gradient that exist in the cross section and along its length is presented. From an approximation of the temperature profile obtained by measurements made in the field and taking into account the boundary conditions of the structure, its displacements are calculated for comparison with the actual values observed. The analytical calculation of the displacements fields and stress fields are executed, using the concept of thermal momentum in the section. (EG) [pt

  12. Instanton transition in thermal and moduli deformed de Sitter cosmology

    International Nuclear Information System (INIS)

    Kounnas, Costas; Partouche, Herve

    2008-01-01

    We consider the de Sitter cosmology deformed by the presence of a thermal bath of radiation and/or time-dependent moduli fields. Depending on the parameters, either a first or second-order phase transition can occur. In the first case, an instanton allows a double analytic continuation. It induces a probability to enter the inflationary evolution by tunnel effect from another cosmological solution. The latter starts with a big bang and, in the case the transition does not occur, ends with a big crunch. A temperature duality exchanges the two cosmological branches. In the limit where the pure de Sitter universe is recovered, the tunnel effect reduces to a 'creation from nothing', due to the vanishing of the big bang branch. However, the latter may be viable in some range of the deformation parameter. In the second case, there is a smooth evolution from a big bang to the inflationary phase

  13. Analyses of deformation and thermal-hydraulics within a wire-wrapped fuel subassembly in a liquid metal fast reactor by the coupled code system

    Energy Technology Data Exchange (ETDEWEB)

    Uwaba, Tomoyuki, E-mail: uwaba.tomoyuki@jaea.go.jp; Ohshima, Hiroyuki; Ito, Masahiro

    2017-06-15

    Highlights: • The coupled computational code system allowed for mechanical and thermal-hydraulic analyses in a fast reactor fuel subassembly. • In this system interactive calculations between flow area deformations and coolant temperature changes are repeated to their convergence state. • Effects on bundle-duct interaction on coolant temperature distributions were investigated by using the code system. - Abstract: The coupled numerical analysis of mechanical and thermal-hydraulic behaviors was performed for a wire-wrapped fuel pin bundle subassembly irradiated in a fast reactor. For the analysis, the fuel pin bundle deformation analysis code BAMBOO and the thermal-hydraulic analysis code ASFRE exchanged the deformation and temperature analysis results through the iterative calculations to attain convergence corresponding to the static balance between deformation and temperature. The analysis by the coupled code system showed that the radial distribution of coolant temperature in the subassembly tended to flatten as a result of the fuel pin bundle deformation governed by cladding void swelling and irradiation creep. Such flattening of temperature distribution was slightly observed as a result of fuel pin bowings due to the cladding-wire interaction even when no bundle-duct interaction occurred. The effect of the spacer wire-pitch on deformation and thermal-hydraulics was also investigated in this study.

  14. Preliminary laboratory investigation of thermally treated recycled concrete aggregate for general use in concrete

    NARCIS (Netherlands)

    Larbi, J.A.; Heijnen, W.M.M.; Brouwer, J.P.; Mulder, E.

    2000-01-01

    This paper deals with a preliminary laboratory study to assess the effectiveness of thermal treatment methods to improve the quality of recycled concrete aggregate. The samples used for the study consisted of sieved fractions of crushed concrete that were subjected to various thermal treatments at

  15. Modeling Thermal Transport and Surface Deformation on Europa using Realistic Rheologies

    Science.gov (United States)

    Linneman, D.; Lavier, L.; Becker, T. W.; Soderlund, K. M.

    2017-12-01

    Most existing studies of Europa's icy shell model the ice as a Maxwell visco-elastic solid or viscous fluid. However, these approaches do not allow for modeling of localized deformation of the brittle part of the ice shell, which is important for understanding the satellite's evolution and unique geology. Here, we model the shell as a visco-elasto-plastic material, with a brittle Mohr-Coulomb elasto-plastic layer on top of a convective Maxwell viscoelastic layer, to investigate how thermal transport processes relate to the observed deformation and topography on Europa's surface. We use Fast Lagrangian Analysis of Continua (FLAC) code, which employs an explicit time-stepping algorithm to simulate deformation processes in Europa's icy shell. Heat transfer drives surface deformation within the icy shell through convection and tidal dissipation due to its elliptical orbit around Jupiter. We first analyze the visco-elastic behavior of a convecting ice layer and the parameters that govern this behavior. The regime of deformation depends on the magnitude of the stress (diffusion creep at low stresses, grain-size-sensitive creep at intermediate stresses, dislocation creep at high stresses), so we calculate effective viscosity each time step using the constitutive stress-strain equation and a combined flow law that accounts for all types of deformation. Tidal dissipation rate is calculated as a function of the temperature-dependent Maxwell relaxation time and the square of the second invariant of the strain rate averaged over each orbital period. After we initiate convection in the viscoelastic layer by instituting an initial temperature perturbation, we then add an elastoplastic layer on top of the convecting layer and analyze how the brittle ice reacts to stresses from below and any resulting topography. We also take into account shear heating along fractures in the brittle layer. We vary factors such as total shell thickness and minimum viscosity, as these parameters are

  16. Thermal Deformation and RF Performance Analyses for the SWOT Large Deployable Ka-Band Reflectarray

    Science.gov (United States)

    Fang, H.; Sunada, E.; Chaubell, J.; Esteban-Fernandez, D.; Thomson, M.; Nicaise, F.

    2010-01-01

    A large deployable antenna technology for the NASA Surface Water and Ocean Topography (SWOT) Mission is currently being developed by JPL in response to NRC Earth Science Tier 2 Decadal Survey recommendations. This technology is required to enable the SWOT mission due to the fact that no currently available antenna is capable of meeting SWOT's demanding Ka-Band remote sensing requirements. One of the key aspects of this antenna development is to minimize the effect of the on-orbit thermal distortion to the antenna RF performance. An analysis process which includes: 1) the on-orbit thermal analysis to obtain the temperature distribution; 2) structural deformation analysis to get the geometry of the antenna surface; and 3) the RF performance with the given deformed antenna surface has been developed to accommodate the development of this antenna technology. The detailed analysis process and some analysis results will be presented and discussed by this paper.

  17. Preliminary investigation on the deformation rates of the Nazimiye Fault (Eastern Turkey)

    Science.gov (United States)

    Sançar, Taylan

    2016-04-01

    The complex tectonic setting of the eastern Mediterranean is mainly shaped by the interaction between three major plates, Eurasian, African, and Arabian plates, with additional involvement from the smaller Anatolian Scholle. The internal deformation of the Anatolian Scholle is mainly accommodated along NW-striking dextral and NE-striking sinistral faults, which are explained by the Prandtl Cell model by Şengör (1979). Although some of these strike-slip faults, such as Tuzgölü, Ecemiş and Malatya-Ovacık faults, have long been documented, the Nazimiye Fault (NF) is only presented in very recent studies (Kara et al. 2013; Emre et al. 2012). The aim of the study is to understand intra-plate deformation of the Anatolian Scholle, by studying the morphotectonic structures along the NF. The study area located close to the eastern boundary of Anatolia, roughly on the wedge that is delimited by the North and East Anatolian shear zones and the Malatya-Ovacık Fault Zone. After the preliminary remote sensing analyses and field observations, I mapped the locations of the different terrace treads along the Pülümür River, which is strongly deflected by the activity of the NF. This dextral strike-slip fault, is not only characterized with the deformation of the Pülümür River, but also it shows many beheaded streams, pressure ridges, hot springs and travertines along its course. I sampled one of the alluvial fans for cosmogenic dating at the eastern section of the NF, where about 20 m of dextral offset was measured at the margins of the incised stream. Moreover, additional sampling was performed from different terrace levels along the Pülümür River, in order not only to estimate the min. horizontal rate, but also to quantify the vertical deformation. Moreover, I applied morphometric indices to understand the tectonic control on the local morphology along the NF. Transverse Topographic Symmetry Factor was used to show the relative degree of tectonic activity along the

  18. Preliminary design characteristics of the RB fast-thermal core 'HERBE'

    International Nuclear Information System (INIS)

    Pesic, M.; Marinkovic, P.

    1989-01-01

    The 'RB' is zero power heavy water critical assembly designed in 1958 in Yugoslavia. The reactor operated using natural metal uranium, 2% enriched metal uranium, and 80% enriched UO 2 fuel of Soviet origin. A study of design of fast neutron fields began in 1976 and three fast neutron fields were designed up to 1983: the external neutron converter, the experimental fuel channel and the internal neutron converter, as the first step to fast-thermal coupled system. The preliminary design characteristics of the HERBE - a new fast - thermal core at the RB reactor are shown in this paper. (author)

  19. Modeling the thermal deformation of TATB-based explosives. Part 1: Thermal expansion of “neat-pressed” polycrystalline TATB

    Energy Technology Data Exchange (ETDEWEB)

    Luscher, Darby J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-05-08

    thermal deformation of engineered components whose consolidation process is generally more complex than isostatic or die-pressed specimens. Finally, an envisioned application of the modeling approach to simulating thermal expansion of weapon systems and components is outlined along with necessary future work to introduce the effects of binder and ratcheting behavior. Key conclusions from this work include the following. Both porosity and grain aspect ratio have an influence on the thermal expansion of polycrystal TATB considering realistic material variability. Thepreferred orientation of the single crystal TATB [001] poles within a polycrystal gives rise to pronounced anisotropy of the macroscopic thermal expansion. The extent of this preferred orientation depends on the magnitude of deformation, and consequently, is expected to vary spatially throughout manufactured components much like porosity. The modeling approach presented here has utility toward bringing spatially variable microstructural features into macroscale system engineering modelsAbstract Not Provided

  20. Preliminary thermal sizing of intermediate heat exchanger for NHDD system

    International Nuclear Information System (INIS)

    Kim, Chan Soo; Hong, Sung Deok; Kim, Yong Wan; Chang, Jongh Wa

    2009-01-01

    Nuclear Hydrogen Development and Demonstration (NHDD) system is a Very High Temperature gascooled Reactor (VHTR) coupled with hydrogen production systems. Intermediate heat exchanger transfers heat from the nuclear reactor to the hydrogen production system. This study presented the sensitivity analysis on a preliminary thermal sizing of the intermediate heat exchanger. Printed Circuit Heat Exchanger (PCHE) was selected for the thermal sizing because the printed circuit heat exchanger has the largest compactness among the heat exchanger types. The analysis was performed to estimate the effect of key parameters including the operating condition of the intermediate system, the geometrical factors of the PCHE, and the working fluid of the intermediate system.

  1. Hierarchical evolution and thermal stability of microstructure with deformation twins in 316 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.J. [Department of Materials Science and Engineering, Texas A& M University, College Station, TX 77843 (United States); Jozaghi, T. [Department of Mechanical Engineering, Texas A& M University, College Station, TX 77843 (United States); Karaman, I., E-mail: ikaraman@tamu.edu [Department of Materials Science and Engineering, Texas A& M University, College Station, TX 77843 (United States); Department of Mechanical Engineering, Texas A& M University, College Station, TX 77843 (United States); Arroyave, R. [Department of Materials Science and Engineering, Texas A& M University, College Station, TX 77843 (United States); Department of Mechanical Engineering, Texas A& M University, College Station, TX 77843 (United States); Chumlyakov, Y.I. [Siberian Physical Technical Institute, Tomsk State University, Tomsk 634050 (Russian Federation)

    2017-05-10

    We report extensive nano-twin formation in 316 stainless steel (SS) and the evolution of a hierarchical microstructure through the formation of multi-scale twin bundles after uniaxial tension with uniform elongation levels of 20%, 30%, and 40%. Multiscale characterization techniques were employed to reveal the nature of these twins. The twin density increases with the increasing strain level, however, the twin width remains the same, notably reducing the mean free path of dislocations. Concurrently, significant work hardening is observed during subsequent deformation. The deformation-induced nano-twins are thermally stable up to ~800 °C, shown by both interrupted and in-situ transmission electron microscopy experiments, above which the recrystallization takes place in the vicinity of the twins. Such favorable thermal stability of the twins in nano-twin strengthened 316 SS offers a promising approach for microstructurally engineering these materials for potential applications at elevated temperatures. The related strengthening mechanisms are discussed in the light of the mean free path of dislocations and the dislocation interactions with twin boundaries.

  2. Preliminary data evaluation for thermal insulation characterization testing

    International Nuclear Information System (INIS)

    DeClue, J.F.; Moses, S.D.; Tollefson, D.A.

    1991-01-01

    The purpose of Thermal Insulation Characterization Testing is to provide physical data to support certain assumptions and calculational techniques used in the criticality safety calculations in Section 6 of the Safety Analysis Reports for Packaging (SARPs) for drum-type packaging for Department of Energy's (DOE) Oak Ridge Y-12 Plant, managed by Martin Marietta Energy Systems, Inc. Results of preliminary data evaluation regarding the fire-test condition reveal that realistic weight loss consideration and residual material characterization in developing calculational models for the hypothetical accident condition is necessary in order to prevent placement of unduly conservative restrictions on shipping requirements as a result of overly conservative modeling. This is particularly important for fast systems. Determination of the geometric arrangement of residual material is of secondary importance. Both the methodology used to determine the minimum thermal insulation mass remaining after the fire test and the treatment of the thermal insulation in the criticality safety calculational models requires additional evaluation. Specific testing to be conducted will provide experimental data with which to validate the mass estimates and calculational modeling techniques for extrapolation to generic drum-type containers

  3. A study of thermal deformation in the carriage of a permanent magnet direct drive linear motor stage

    International Nuclear Information System (INIS)

    Chow, J.H.; Zhong, Z.W.; Lin, W.; Khoo, L.P.

    2012-01-01

    Carriage deformation due to temperature gradients within the materials of the carriage affects the accuracy of precision machines. This is largely due to the indeterminist temperature distribution in the carriage's material caused by the non-linearity of heat transfer. The joule heat from the motor coil forms the main heat source. When coupled with the heat loss through convection and radiation, the temperature variation in the motor's carriage also increases. In this study, the Finite Element Analysis was used together with a set of boundary conditions, which was obtained empirically, to analyze the distortion of the motor's carriage. The simulated results were compared with those obtained through experiments. The study shows that it is important to know, rather than to assume, the thermal boundary conditions of the motor's carriage of a precision machine in order to accurately estimate the thermal deformation of the carriage in precision machining. - Highlights: ► Deformation occurs in carriages which are mounted with linear motor. ► The convective coefficient, which is assumed to be 10 W mm −2 , is shown to be invalid. ► The perfect contact conductance is shown to be invalid too. ► To have an accurate thermal model, boundary conditions have to be realistic. ► Boundary conditions are the heat source, convective and conductance values.

  4. Investigation of hydrogen-deformation interactions in β-21S titanium alloy using thermal desorption spectroscopy

    International Nuclear Information System (INIS)

    Tal-Gutelmacher, E.; Eliezer, D.; Boellinghaus, Th.

    2007-01-01

    The focus of this paper is the investigation of the combined influence of hydrogen and pre-plastic deformation on hydrogen's absorption/desorption behavior, the microstructure and microhardness of a single-phased β-21S alloy. In this study, thermal desorption analyses (TDS) evaluation of various desorption and trapping parameters provide further insight on the relationships between hydrogen absorption/desorption processes and deformation, and their mutual influence on the microstructure and the microhardness of β-21S alloy. TDS spectra were supported by other experimental techniques, such as X-ray diffraction, scanning and transmission electron microscopy, hydrogen quantity analyses and microhardness tests. Pre-plastic deformation, performed before the electrochemical hydrogenation of the alloy, increased significantly the hydrogen absorption capacity. Its influence was also evident on the notably expanded lattice parameter of β-21S alloy after hydrogenation. However, no hydride precipitation was observed. An interesting softening effect of the pre-deformed hydrogenated alloy was revealed by microhardness tests. TDS demonstrated the significant effect of pre-plastic deformation on the hydrogen evolution process. Hydrogen desorption temperature and the activation energy for hydrogen release increased, additional trap states were observed and the amount of desorbed hydrogen decreased

  5. Deformed Reality: Proof of concept and preliminary results

    OpenAIRE

    Haouchine , Nazim; Petit , Antoine; Roy , Frederick; Cotin , Stéphane

    2017-01-01

    International audience; We introduce " Deformed Reality " , a new paradigm to interactively manipulate objects in a scene in a deformable manner. Using the core principle of augmented reality to estimate rigid pose over time, our method enables the user to deform the targeted object while it is being rendered with its natural texture, giving the sense of a real-time object editing in user environment. The presented results show that our method can open new ways of using augmented reality by n...

  6. Development of a preliminary PIRT (Phenomena Identification and Ranking Table) of thermal-hydraulic phenomena for SMART

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Bub Dong; Lee, Won Jae; Kim, Hee Cheol; Song, Jin Ho; Sim, Suk Ku [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    The work reported in this paper identifies the thermal-hydraulic phenomena that are expected to occur during a number of key transients in SMART (System-integrated Modular Advanced ReacTor) which is under development at KAERI. The result of this effort is based on the current design concept of SMART integral reactor. Although the design is still evolving, the preliminary Phenomena Identification and Ranking Table (PIRT) has been developed based on the experts` knowledge and experience. The preliminary PIRT has been developed by consensus of KAERI expert panelists and AHP (Analytical Hierarchy Process). Preliminary PIRT developed in this paper is intended to be used to identify and integrate development areas of further experimental tests needed, thermal hydraulic models and correlations and code improvements for the safety analysis of the SMART. 8 refs., 4 tabs (Author)

  7. Development of a preliminary PIRT (Phenomena Identification and Ranking Table) of thermal-hydraulic phenomena for SMART

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Bub Dong; Lee, Won Jae; Kim, Hee Cheol; Song, Jin Ho; Sim, Suk Ku [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    The work reported in this paper identifies the thermal-hydraulic phenomena that are expected to occur during a number of key transients in SMART (System-integrated Modular Advanced ReacTor) which is under development at KAERI. The result of this effort is based on the current design concept of SMART integral reactor. Although the design is still evolving, the preliminary Phenomena Identification and Ranking Table (PIRT) has been developed based on the experts` knowledge and experience. The preliminary PIRT has been developed by consensus of KAERI expert panelists and AHP (Analytical Hierarchy Process). Preliminary PIRT developed in this paper is intended to be used to identify and integrate development areas of further experimental tests needed, thermal hydraulic models and correlations and code improvements for the safety analysis of the SMART. 8 refs., 4 tabs (Author)

  8. Development of a preliminary PIRT(Phenomena Indentification and Ranking Table) of thermal-hydraulic phenomena for SMART

    International Nuclear Information System (INIS)

    Chung, Bub Dong; Lee, Won Jae; Kim, Hee Cheol; Song, Jin Ho; Sim, Suk Ku

    1997-01-01

    The work reported in this paper identifies the thermal-hydraluic phenomena that are expected to occur during a number of key transients in SMART (System-integrated Modular Advanced ReacTor) which is under development at KAERI. The result of this effort is based on the current design concept of SMART integral reactor. Although the design is still evolving, the preliminary Phenomena Identification and Ranking Table (PIRT) has been developed based on the expert's knowledge and experience. The preliminary PIRT has been developed by consensus of KAERI expert panelists and AHP (Analytical Hierachy Process). Preliminary PIRT developed in this paper is intended to be used to identify and integrate development areas of further experimental test needed, thermal hydraulic models and correlations and code improvements for the safety analysis of the SMART

  9. Improvement of computer programs 'BAMBOO' and 'ASFRE-IV' for coupling analysis of deformation and thermal-hydraulics in a high burn-up fuel subassembly of fast reactor

    International Nuclear Information System (INIS)

    Uwaba, Tomoyuki; Ohshima, Hiroyuki; Imai, Yasutomo

    2003-04-01

    A simulation system of a deformed fuel subassembly is being developed for the structure integrity of high burn-up wire-spacer-type fuel subassemblies of sodium-cooled fast breeder reactors. This report describes a computer program improvement work for coupling analyses of deformation and thermal-hydraulics in a fuel subassembly as part of the simulation system development. In this work, a function of data conversion as an interface between a bundle deformation analysis program BAMBOO and a thermal hydraulic analysis program ASFRE-IV was incorporated to each program. BAMBOO was improved to accept the coolant temperature data from ASFRE-IV and to offer bundle deformation data to ASFRE-IV. ASFRE-IV was also improved to offer the coolant temperature data to BAMBOO and to obtain the bundle deformation data from BAMBOO. Improved BAMBOO and ASFRE-IV were applied to an analysis of 169-pin bundle for the program verification. It was confirmed that the coupling analysis gave the physically reasonable results on both deformation and thermal hydraulic behaviors in the fuel subassembly. (author)

  10. KALIMER fuel system preliminary design description

    International Nuclear Information System (INIS)

    Hwang, Woan; Lee, B.O.; Nam, C.; Paek, S.K.

    1998-10-01

    This document provides general design concepts, design basis, preliminary design specification and design technologies which are needed for designing the fuel/non-fuel rods and assembly ducts of the KALIMER fuel system. The core of LMFBR consists of driver fuel assembly, blanket assembly, reflector assembly, shielding assembly, control assembly and GEM (Gas Expansion Module) as well as USS, dummy assembly, detector assembly. These core components must be designed to withstand the high temperature, high flux for a long irradiation exposure time. Due to the high temperature and high flux, irradiation creep and swelling as well as thermal-mechanical deformation are occurred at the fuel/non-fuel system and cause the deformations of materials and the geometric deflections at fuel/non-fuel rods, assembly ducts and components. In order to overcome these intricate phenomena through the engineering design, the design basis including theoretical analysis methodologies and design considerations, material characteristics of fuel system, and the specifications and drawings of fuel/non-fuel rods and assembly ducts, respectively, are presented. This document is preliminary design description which is produced in the conceptual design stage, and does not present the detailed and finalized design data which can be for the manufacturing. (author). 22 refs

  11. Effect of deformation on the thermal conductivity of granular porous media with rough grain surface

    Science.gov (United States)

    Askari, Roohollah; Hejazi, S. Hossein; Sahimi, Muhammad

    2017-08-01

    Heat transfer in granular porous media is an important phenomenon that is relevant to a wide variety of problems, including geothermal reservoirs and enhanced oil recovery by thermal methods. Resistance to flow of heat in the contact area between the grains strongly influences the effective thermal conductivity of such porous media. Extensive experiments have indicated that the roughness of the grains' surface follows self-affine fractal stochastic functions, and thus, the contact resistance cannot be accounted for by models based on smooth surfaces. Despite the significance of rough contact area, the resistance has been accounted for by a fitting parameter in the models of heat transfer. In this Letter we report on a study of conduction in a packing of particles that contains a fluid of a given conductivity, with each grain having a rough self-affine surface, and is under an external compressive pressure. The deformation of the contact area depends on the fractal dimension that characterizes the grains' rough surface, as well as their Young's modulus. Excellent qualitative agreement is obtained with experimental data. Deformation of granular porous media with grains that have rough self-affine fractal surface is simulated. Thermal contact resistance between grains with rough surfaces is incorporated into the numerical simulation of heat conduction under compressive pressure. By increasing compressive pressure, thermal conductivity is enhanced more in the grains with smoother surfaces and lower Young's modulus. Excellent qualitative agreement is obtained with the experimental data.

  12. Feasibility study of thermal insulation materials for core support of experimental VHTR

    International Nuclear Information System (INIS)

    Kawakami, H.; Nakanishi, T.

    1982-01-01

    Thermal insulation materials for core support of the experimental VHTR, planned by JAERI, should maintain moderate compressive strength and dimensional stability as well as low thermal conductivity at the maximum service temperature of 1100 0 C for 20 years. For selecting materials, we investigate properties of some candidates, and evaluate their feasibility. Preliminary tests, heat treatment test and compressive creep tests for 1000 hours at 900 0 C and 1000 0 C were conducted. In the preliminary tests, EG-38B (carbon baked at 1350 0 C) and Fine Finnex 600 (silicon nitride) showed acceptable physical stability. In the heat treatment tests, silicon nitride showed weight loss probably caused by thermal decomposition. Compressive creep deformation of Fine Finnex 600 was negligible under stress of 100 kg/cm 2 for 1000 hours. Heat treatment at 1200 to 1300 0 C for 50 hours improved dimensional stability of carbon at 1000 0 C

  13. Non-Contact Acousto-Thermal Signatures of Plastic Deformation in TI-6AL-4V

    Science.gov (United States)

    Welter, J. T.; Malott, G.; Schehl, N.; Sathish, S.; Jata, K. V.; Blodgett, M. P.

    2010-02-01

    Plastic deformation introduces changes in a material which include increases in: dislocations, strains, residual stress, and yield stress. However, these changes have a very small impact on the material properties such as elastic modulus, conductivity and ultrasonic wave speed. This is due to the fact that interatomic forces govern these properties, and they are not affected by plastic deformation to any large degree. This is evident from the fact that the changes in electrical resistance and ultrasonic velocity in plastically deformed and virgin samples are very small and can only be determined by highly controlled experiments. Except for X-ray diffraction, there are no direct nondestructive methods for measuring strain and the residual stress. This paper presents an application of the non-contact acousto-thermal signature (NCATS) NDE methodology to detect plastic deformation in flat dog bone Ti-6Al-4V samples. Results of the NCATS measurements on samples subjected to incremental amounts of plastic deformation are presented. The maximum temperature attained by the sample due to acoustic excitation is found to be sensitive to the amount of plastic strain. It is observed that the temperature induced by acoustic excitation increases to a peak followed by a decrease to failure. The maximum temperature peak occurs at plastic strains of 12-14%. It is observed that there is a correlation between the peak in maximum temperature rise and the strain at the experimentally determined ultimate tensile strength. A microstructural based explanation for this will be presented. The results are discussed in reference to utilizing this technique for detection and evaluation of plastic deformation.

  14. Preliminary design of the thermal protection system for solar probe

    Science.gov (United States)

    Dirling, R. B., Jr.; Loomis, W. C.; Heightland, C. N.

    1982-01-01

    A preliminary design of the thermal protection system for the NASA Solar Probe spacecraft is presented. As presently conceived, the spacecraft will be launched by the Space Shuttle on a Jovian swing-by trajectory and at perihelion approach to three solar radii of the surface of the Earth's sun. The system design satisfies maximum envelope, structural integrity, equipotential, and mass loss/contamination requirements by employing lightweight carbon-carbon emissive shields. The primary shield is a thin shell, 15.5-deg half-angle cone which absorbs direct solar flux at up to 10-deg off-nadir spacecraft pointing angles. Secondary shields of sandwich construction and low thickness-direction thermal conductivity are used to reduce the primary shield infrared radiation to the spacecraft payload.

  15. Inelastic deformations of fault and shear zones in granitic rock

    International Nuclear Information System (INIS)

    Wilder, D.G.

    1986-02-01

    Deformations during heating and cooling of three drifts in granitic rock were influenced by the presence of faults and shear zones. Thermal deformations were significantly larger in sheared and faulted zones than where the rock was jointed, but neither sheared nor faulted. Furthermore, thermal deformations in faulted or sheared rock were not significantly recovered during subsequent cooling, thus a permanent deformation remained. This inelastic response is in contrast with elastic behavior identified in unfaulted and unsheared rock segments. A companion paper indicates that deformations in unsheared or unfaulted rock were effectively modeled as an elastic response. We conclude that permanent deformations occurred in fractures with crushed minerals and fracture filling or gouge materials. Potential mechanisms for this permanent deformation are asperity readjustments during thermal deformations, micro-shearing, asperity crushing and crushing of the secondary fracture filling minerals. Additionally, modulus differences in sheared or faulted rock as compared to more intact rock would result in greater deformations in response to the same thermal loads

  16. Deformations and Displacements of the LHC Superconducting Dipoles Induced by Standard and Non-Standard Operational Modes

    CERN Document Server

    La China, M; Gubello, G; Scandale, Walter

    2004-01-01

    A full-scale and fully-instrumented working model of the LHC lattice cell has been tested at CERN between March and December 2002. Aside of the current, pressure and temperature sensors, controlled by an industrial supervision system, a novel device has been set to monitor magnet positions with respect to the surrounding cryostat. The series of operating modes to test cryogenics, current leads and quench recovery electronics offered the chance to investigate potentially harmful deformations of the superconducting structure. In this paper we present a survey of displacements and deformations experienced by the LHC cell magnets during thermal cycles, current ramps and resistive transitions. Although the system complexity prevented from complete modeling, a preliminary phenomena explanation is given.

  17. Numerical modelling of stresses and deformations in casting processes

    DEFF Research Database (Denmark)

    Hattel, Jesper Henri

    1997-01-01

    Keywords: Stresses and deformations, casting, governing equations, thermal strain, control volume method......Keywords: Stresses and deformations, casting, governing equations, thermal strain, control volume method...

  18. Thermal Stability of Microstructure and Microhardness of Heterophase BCC-Alloys After Torsional Deformation on Bridgman Anvils

    Science.gov (United States)

    Ditenberg, I. A.; Tyumentsev, A. N.

    2018-03-01

    The results of investigations of thermal stability of microstructure and microhardness of alloys of the V-4Ti-4Cr and Mo-47Re systems, subjected to torsional deformation by high quasi-hydrostatic pressure at room temperature, are reported. It is shown that submicrocrystalline and nanocrystalline states, and the respective high values of microhardness, persist up to the upper bound ( 0.4 Tmelt) of the temperature interval of their recovery and polygonization in a single-phase state. The main factors ensuring thermal stability of highlydefective states in heterophase alloys are discussed.

  19. Thermal-deformation effect of welding on A 1 reactor pressure vessel weld joints properties and state of stress

    International Nuclear Information System (INIS)

    Becka, J.; Kupka, I.

    1976-01-01

    The methods are compared of electroslag welding and of arc welding with a view to their possible application in welding the Bohunice A-1 reactor pressure vessel. Considered are the thermal deformation effects of welding on the physical properties and the stress present in welded joints. For testing, plates were used having the dimensions of 1100x2300x200 mm and rings with 4820 mm outer diameter, 1800 mm height and 170 mm thickness made of steel CSN 413O30 modified with Ni, Al+Ti. The deformation effect of welding on the residual surface and triaxial stress, the specific stored energy, the initiation temperature of brittle crack and the critical size of the initiation defect corresponding to the thermal deformation effect of welding were determined. It was found that for electroslag welding, there is a low probability of crack formation in the joints, a low level of residual stress and a low level of specific stored energy in a relatively wide joint zone. For arc welding there is a considerable probability of defect formation in the vicinity of the sharp boundary of the joint, a high level of the triaxial state of stress in the tensile region, and a high level of specific stored energy concentrated in the narrow zone of weld joints. The recommended thermal process is given for welding pressure vessels made of the CSN 413030 steel modified with Ni, Al+Ti, and 150 to 200 mm in thickness. (J.P.)

  20. Some contributions to the high strain rate deformation of solids and the thermally activated deformation of wood

    International Nuclear Information System (INIS)

    Ferguson, W George

    2009-01-01

    The behaviour of metals as a function of rate of loading, strain rate, and temperature is discussed in terms of previous work by the author. Strain rates range from 10 -3 s -1 , obtained in a standard tensile testing machine, to 10 2 s -1 obtained in a hydraulic piston driven machine and up to 10 4 s -1 , very high strain rates with a Kolsky split Hopkinson bar using shear type loading. At rates less 10 3 s -1 the strength is a function of strain rate and temperature, is thermally activated and governed by the stress-assisted thermal activation of dislocations across short-range barriers in the crystal. At very high strain rates however the behaviour is controlled by interaction of dislocations with either phonons or electrons, giving a strength proportional to strain rate. The compressive strength of small clear samples of wood, Pinus radiata and Kahikatea, determined over the strain rate range 10 -3 s -1 to 10 3 s -1 as a function of strain rate, temperature and moisture content shows the behaviour to again be thermally activated with the strength a function of stain rate, temperature and moisture content. A rate theory of deformation is developed where the yield behaviour of wood is assumed to result from the stress-assisted thermally activated motion of elementary fibrils over short-range barriers. The moisture is assumed to affect the bond energy between elementary fibrils and the barrier energy is taken to be a linear decreasing function of increasing moisture content and the moisture to act like a plasticiser in separating the elementary fibrils. The theory more than adequately explains the observed behaviour.

  1. Deformation and velocity measurements at elevated temperature in a fractured 0.5 M block of tuff

    International Nuclear Information System (INIS)

    Blair, S.C.; Berge, P.A.

    1996-01-01

    This paper presents preliminary results of laboratory tests conducted on small block samples of Topopah Spring tuff, in support of the Yucca Mountain Site Characterization Project. The overall objective of these tests is to investigate the thermal-mechanical, thermal-hydrological, and thermal-chemical response of the rock to conditions similar to the near-field environment (NFE) of a potential nuclear waste repository. We present preliminary results of deformation and elastic wave velocity measurements on a 0.5-m-scale block of Topopah Spring tuff tested in uniaxial compression to 8.5 MPa and at temperatures to 85 degree C. The Young's modulus was found to be about 7 to 31 GPa for vertical measurements parallel to the stress direction across parts of the block containing no fractures or a few fractures, and 0.5 to 0.9 GPA for measurements across individual fractures, at ambient temperature and 8.5 MPa maximum stress. During stress cycles between 5 and 8.5 MPa, the deformation modulus values for the matrix with fractures were near 15-20 GPa at ambient temperature but dropped to about 10 GPa at 85 degree C. Compressional wave velocities were found to be about 3.6 to 4.7 km/s at ambient temperature and stress. After the stress was cycled, velocities dropped to values as low as 2.6 km/s in the south end of the block where vertical cracks developed. Heating the block to about 85 degree C raised velocities to as much as 5.6 km/s in the upper third of the block

  2. Preliminary study on acceptability of scope of thermal discharge mixing zone for nuclear power plant

    International Nuclear Information System (INIS)

    Liu Yongye; Yang Yang; Wang Liang; Chen Xiaoqiu; Liu Senlin

    2012-01-01

    Based on the situation that the existing domestic temperature control standards are not performable, the preliminary study on the acceptability of the mixing zone scope of thermal discharge for nuclear power plant was conducted in this paper, taking a coastal power station SNP as a case. The following preliminary conclusions could be drawn from the results of cluster analysis of the SNP site under different results of mathematical modeling and physical model test: 1) The influence intensity of ecological function of the SNP site seawater is small and the scope of thermal discharge mixing zone is acceptable under SNP-1 (Unit 1 and 2) operating condition; 2) the influence intensity of ecological function of the SNP site seawater is small and the scope of thermal discharge mixing zone is acceptable in spring under SNP-1 (Unit 1 and 2) and SNP-2 (Unit 3 and 4) operating condition, while the influence intensity of ecological function of the SNP site seawater is large and the scope of mixing zone is unacceptable in autumn under the same operating condition. (authors)

  3. Partitioning planning studies: Preliminary evaluation of metal and radionuclide partitioning the high-temperature thermal treatment systems

    International Nuclear Information System (INIS)

    Liekhus, K.; Grandy, J.; Chambers, A.

    1997-03-01

    A preliminary study of toxic metals and radionuclide partitioning during high-temperature processing of mixed waste has been conducted during Fiscal Year 1996 within the Environmental Management Technology Evaluation Project. The study included: (a) identification of relevant partitioning mechanisms that cause feed material to be distributed between the solid, molten, and gas phases within a thermal treatment system; (b) evaluations of existing test data from applicable demonstration test programs as a means to identify and understand elemental and species partitioning; and, (c) evaluation of theoretical or empirical partitioning models for use in predicting elemental or species partitioning in a thermal treatment system. This preliminary study was conducted to identify the need for and the viability of developing the tools capable of describing and predicting toxic metals and radionuclide partitioning in the most applicable mixed waste thermal treatment processes. This document presents the results and recommendations resulting from this study that may serve as an impetus for developing and implementing these predictive tools

  4. Partitioning planning studies: Preliminary evaluation of metal and radionuclide partitioning the high-temperature thermal treatment systems

    Energy Technology Data Exchange (ETDEWEB)

    Liekhus, K.; Grandy, J.; Chambers, A. [and others

    1997-03-01

    A preliminary study of toxic metals and radionuclide partitioning during high-temperature processing of mixed waste has been conducted during Fiscal Year 1996 within the Environmental Management Technology Evaluation Project. The study included: (a) identification of relevant partitioning mechanisms that cause feed material to be distributed between the solid, molten, and gas phases within a thermal treatment system; (b) evaluations of existing test data from applicable demonstration test programs as a means to identify and understand elemental and species partitioning; and, (c) evaluation of theoretical or empirical partitioning models for use in predicting elemental or species partitioning in a thermal treatment system. This preliminary study was conducted to identify the need for and the viability of developing the tools capable of describing and predicting toxic metals and radionuclide partitioning in the most applicable mixed waste thermal treatment processes. This document presents the results and recommendations resulting from this study that may serve as an impetus for developing and implementing these predictive tools.

  5. Thermal treatment of recycled concrete aggegate for general use in concrete. A preliminary study

    NARCIS (Netherlands)

    Larbi, J.A.; Heijnen, W.M.M.; Brouwer, J.P.; Mulder, E.

    2000-01-01

    In this paper, the results of a preliminary laboratory study to assess the effectiveness of thermally treating recycled concrete aggregate for genera) use in concrete are presented. The samples used for the study consisted of sieved fractions of crushed concrete that were subjected to various

  6. Deformation and rupture of a horizontal liquid layer by thermal and solutal Marangoni flows

    Energy Technology Data Exchange (ETDEWEB)

    Viviani, Antonio [Seconda Universita di Napoli (SUN), Dipartimento di Ingegneria Aerospaziale e Meccanica (DIAM), via Roma 29, 81031 Aversa (Italy); Zuev, Andrew [Institute of Continuous Media Mechanics, UB Russian Academy of Sciences, Academic Korolev Street 1, 614013 Perm (Russian Federation)

    2008-11-15

    The evolution of strong surface deformation of a thin viscous fluid layer on a horizontal solid wettable substrate was studied experimentally. Layer deformation is caused by the concentration gradient of surface tension generated by a drop of soluble surfactant placed on the free layer surface. The conditions leading to the layer rupture and drying of the bottom section under the spreading drop were studied. The dependence of the dry spot radius on time, horizontal dimension and thickness of the layer, volume of the introduced droplet and fluids properties, were obtained for various fluid pairs. It was found that the critical initial thickness of the layer, at which its deformation reaches the layer bottom, is practically insensitive to the quantity of the applied surfactant and is defined by the difference in surface tension between the drop and the layer. Comparison of the data with the results of the study of the thermocapillary rupture of a cylindrical layer heated at the center and cooled along the periphery showed good agreement between the dependences of the critical layer thickness on the thermal and the solutal surface tension difference. (author)

  7. Effects of thermal residual stresses and fiber packing on deformation of metal-matrix composites

    International Nuclear Information System (INIS)

    Nakamura, T.; Suresh, S.

    1993-01-01

    The combined effects of thermal residual stresses and fiber spatial distribution on the deformation of a 6061 aluminum alloy containing a fixed concentration unidirectional boron fibers have been analyzed using detailed finite element models. The geometrical structure includes perfectly periodic, uniformly space fiber arrangements in square and hexagonal cells, as well as different cells in which either 30 or 60 fibers are randomly placed in the ductile matrix. The model involves an elastic-plastic matrix, elastic fibers, and mechanically bonded interfaces. The results indicate that both fiber packing and thermal residual stresses can have a significant effect on the stress-strain characteristics of the composite. The thermal residual stresses cause pronounced matrix yielding which also influences the apparent overall stiffness of the composite during the initial stages of subsequent far-field loading along the axial and transverse direction. Furthermore, the thermal residual stresses apparently elevate the flow stress of the composite during transverse tension. Such effects can be traced back to the level of constraint imposed on the matrix by local fiber spacing. The implications of the present results to the processing of the composites are also briefly addressed

  8. Preliminary design and thermal analysis of device for finish cooling Jaffa biscuits in a.d. 'Jaffa'- Crvenka

    Directory of Open Access Journals (Sweden)

    Salemović Duško R.

    2015-01-01

    Full Text Available In this paper preliminary design of device for finish cooling chocolate topping of biscuits in A.D. 'Jaffa'- Crvenka was done. The proposed preliminary design followed by the required technological process of finish cooling biscuits and required parameters of process which was supposed to get and which represented part of project task. Thermal analysis was made and obtained percentage error between surface contact of the air and chocolate topping, obtained from heat balance and geometrical over proposed preliminary design, wasn't more than 0.67%. This is a preliminary design completely justified because using required length of belt conveyor receive required temperature of chocolate topping at the end of the cooling process.

  9. Rock deformation in hydrothermal systems: the nature of fractures in plutons and their host rocks. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Norton, D.

    1981-11-01

    The purpose of this program is to accumulate the types of field data which are important for the analysis of magma-hydrothermal systems. The structural effects of thermal processes were identified in order to distinguish the thermally induced deformations from the deformations that occurred subsequent to complete cooling of the system. Mapping techniques were developed to record the structural data on the ground from local domains characteristic of larger areas in the magma chamber, and in the air from low-angle oblique aerial photography of the entire region. The ground system is complete and preliminary testing is currently being carried out to verify the method. The results indicate that granitic crystalline rocks have no structural resistance to thermal perturbations. If nuclear wastes are to be stored in granite, precautionary buffers would have to be incorporated into the system. A total of 30 fossil magma chambers have been studied over the past 2 years. An extensive set of fracture imagery has been collected, together with information related to the geological history of the plutons. Fossil magma chambers in Arizona, Utah, California, Washington, Montana, and British Columbia have been studied.

  10. Thermal Hydraulic Computational Fluid Dynamics Simulations and Experimental Investigation of Deformed Fuel Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Mays, Brian [AREVA Federal Services, Lynchburg, VA (United States); Jackson, R. Brian [TerraPower, Bellevue, WA (United States)

    2017-03-08

    The project, Toward a Longer Life Core: Thermal Hydraulic CFD Simulations and Experimental Investigation of Deformed Fuel Assemblies, DOE Project code DE-NE0008321, was a verification and validation project for flow and heat transfer through wire wrapped simulated liquid metal fuel assemblies that included both experiments and computational fluid dynamics simulations of those experiments. This project was a two year collaboration between AREVA, TerraPower, Argonne National Laboratory and Texas A&M University. Experiments were performed by AREVA and Texas A&M University. Numerical simulations of these experiments were performed by TerraPower and Argonne National Lab. Project management was performed by AREVA Federal Services. The first of a kind project resulted in the production of both local point temperature measurements and local flow mixing experiment data paired with numerical simulation benchmarking of the experiments. The project experiments included the largest wire-wrapped pin assembly Mass Index of Refraction (MIR) experiment in the world, the first known wire-wrapped assembly experiment with deformed duct geometries and the largest numerical simulations ever produced for wire-wrapped bundles.

  11. Model of the Evolution of Deformation Defects and Irreversible Strain at Thermal Cycling of Stressed TiNi Alloy Specimen

    Directory of Open Access Journals (Sweden)

    Volkov Aleksandr E.

    2015-01-01

    Full Text Available This microstructural model deals with simulation both of the reversible and irreversible deformation of a shape memory alloy (SMA. The martensitic transformation and the irreversible deformation due to the plastic accommodation of martensite are considered on the microscopic level. The irreversible deformation is described from the standpoint of the plastic flow theory. Isotropic hardening and kinematic hardening are taken into account and are related to the densities of scattered and oriented deformation defects. It is supposed that the phase transformation and the micro plastic deformation are caused by the generalized thermodynamic forces, which are the derivatives of the Gibbs’ potential of the two-phase body. In terms of these forces conditions for the phase transformation and for the micro plastic deformation on the micro level are formulated. The macro deformation of the representative volume of the polycrystal is calculated by averaging of the micro strains related to the evolution of the martensite Bain’s variants in each grain comprising this volume. The proposed model allowed simulating the evolution of the reversible and of the irreversible strains of a stressed SMA specimen under thermal cycles. The results show a good qualitative agreement with available experimental data. Specifically, it is shown that the model can describe a rather big irreversible strain in the first thermocycle and its fast decrease with the number of cycles.

  12. Effects of thermal deformation on optical instruments for space application

    Science.gov (United States)

    Segato, E.; Da Deppo, V.; Debei, S.; Cremonese, G.

    2017-11-01

    Optical instruments for space missions work in hostile environment, it's thus necessary to accurately study the effects of ambient parameters variations on the equipment. In particular optical instruments are very sensitive to ambient conditions, especially temperature. This variable can cause dilatations and misalignments of the optical elements, and can also lead to rise of dangerous stresses in the optics. Their displacements and the deformations degrade the quality of the sampled images. In this work a method for studying the effects of the temperature variations on the performance of imaging instrument is presented. The optics and their mountings are modeled and processed by a thermo-mechanical Finite Element Model (FEM) analysis, then the output data, which describe the deformations of the optical element surfaces, are elaborated using an ad hoc MATLAB routine: a non-linear least square optimization algorithm is adopted to determine the surface equations (plane, spherical, nth polynomial) which best fit the data. The obtained mathematical surface representations are then directly imported into ZEMAX for sequential raytracing analysis. The results are the variations of the Spot Diagrams, of the MTF curves and of the Diffraction Ensquared Energy due to simulated thermal loads. This method has been successfully applied to the Stereo Camera for the BepiColombo mission reproducing expected operative conditions. The results help to design and compare different optical housing systems for a feasible solution and show that it is preferable to use kinematic constraints on prisms and lenses to minimize the variation of the optical performance of the Stereo Camera.

  13. Impact of thermal conductivity models on the coupling of heat transport, oxygen diffusion, and deformation in (U, Pu)O nuclear fuel elements

    Science.gov (United States)

    Mihaila, Bogdan; Stan, Marius; Crapps, Justin; Yun, Di

    2013-02-01

    We study the coupled thermal transport, oxygen diffusion, and thermal expansion in a generic nuclear fuel rod consisting of a (U) fuel pellet separated by a helium gap from zircaloy cladding. Steady-state and time-dependent finite-element simulations with a variety of initial- and boundary-value conditions are used to study the effect of the Pu content, y, and deviation from stoichiometry, x, on the temperature and deformation profiles in this fuel element. We find that the equilibrium radial temperature and deformation profiles are most sensitive to x at small values of y. For larger values of y, the effects of oxygen and Pu content are equally important. Following a change in the heat-generation rate, the centerline temperature, the radial deformation of the fuel pellet, and the centerline deviation from stoichiometry track each other closely in (U,Pu)O, as the characteristic time scales of the heat transport and oxygen diffusion are similar. This result is different from the situation observed in the case of UO fuels.

  14. Correlation between thermal gradient and flexure-type deformation as a potential trigger for exfoliation-related rock falls (Invited)

    Science.gov (United States)

    Collins, B. D.; Stock, G. M.

    2010-12-01

    Stress-induced exfoliation of granitic rocks is an important means by which cliffs deform and subsequently erode. During exfoliation, fractures are formed, and when exposed in cliff faces, are susceptible to subsequent rock falls. This is the case in Yosemite National Park, California, where exfoliation continues to play a primary role in cliff evolution. In Yosemite, numerous mechanisms are inferred to trigger rock falls; nevertheless, many rock falls have no recognized triggers. As a result, several potential, but as yet unquantified, triggering mechanisms have been proposed. One of these, thermally induced flexure, wherein solar radiation and temperature variation drives cumulative deformation of partially detached rock flakes, has the potential to explain several recent rock falls in Yosemite. We explore this potential mechanism by quantifying the deformation, temperature, and solar radiation exposure of a near-vertical rock flake in Yosemite Valley. The flake, 14 m tall, 4 m wide and 12 cm thick, receives direct sunlight during most of the day. Whereas the flake is attached to the cliff face at its bottom and top, the sides are detached from the cliff by a 10 cm wide crack on one side, tapering to a 1 cm wide crack on the opposite side. Instrumentation consists of three custom-designed crackmeters placed between the flake and the adjacent cliff face, three air temperature sensors located behind the flake, and three dual air temperature-light sensors located on the outside surface of the flake. Nearby relative humidity and barometric pressure sensors complete the instrumentation. Five-minute interval data from spring - fall 2010 indicate the flake undergoes maximum deformation at mid-span between attachment points and that it deforms from both diurnal and climatic temperature fluctuations. Recorded maximum deformations, measured perpendicular to crack orientation, are 1 cm diurnally and nearly 1.5 cm (including diurnal effect) over a 5-day period of cooler

  15. Development of a preliminary PIRT (Phenomena Identification and Ranking Table) of thermal-hydraulic phenomena for 330MWt SMART integral reactor

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B. D.; Lee, W. J.; Sim, S. K.; Song, J. H.; Kim, H. C.

    1997-09-01

    The work reported in this document identifies the thermal-hydraulic phenomena that are expected to occur during a number of key transients in a 330 MWt SMART integral reactor which is under development at KAERI. The result of this efforts is based on the current design concept of SMART integral reactor. Although the design is still evolving, the preliminary Phenomena Identification and Ranking Table (PIRT) has been developed based on the experts` knowledge and experience. The preliminary PIRT has been developed by the consensus of KAERI expert panelists and AHP (Analytical Hierarchy Process). Preliminary PIRT developed in this report is intended for use to identify and integrate development areas of further experimental tests needed and thermal-hydraulic models and correlations and code improvements for the safety analysis of the SMART integral reactor. (author). 7 refs., 21 tabs., 22 figs.

  16. Design of durability and lifetime assessment method under thermomechanical stress for thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hyun Gyoo; Choi, Young Kue; Jeon, Seol; Lee, Hee Soo [Pusan National University, Busan (Korea, Republic of); Jeon, Min Seok [Korea Testing Laboratory, Seoul (Korea, Republic of)

    2014-01-15

    A durability testing method under thermo-mechanical stress for thermal barrier coatings (TBC) specimens was designed by a combination of an electric furnace and a tensile testing machine, which was done on TBCs on NIMONIC 263 substrates by an atmospheric plasma spraying (APS) deposition method. The testing conditions were chosen according to a preliminary experiment that identified the elastic deformation region of the top coating and the substrate during mechanical loading. Surface cracking and a decrease in the thickness of the top coating, which are typical degradation behaviors under conventional thermal shock testing, were observed after the designed thermal fatigue test, and delamination at the top coating-bond coating interface occurred by the mechanical load. Lifetime assessment was conducted by statistical software using life cycle data which were obtained after the thermal fatigue test.

  17. Preliminary hazards analysis of thermal scrap stabilization system. Revision 1

    International Nuclear Information System (INIS)

    Lewis, W.S.

    1994-01-01

    This preliminary analysis examined the HA-21I glovebox and its supporting systems for potential process hazards. Upon further analysis, the thermal stabilization system has been installed in gloveboxes HC-21A and HC-21C. The use of HC-21C and HC-21A simplified the initial safety analysis. In addition, these gloveboxes were cleaner and required less modification for operation than glovebox HA-21I. While this document refers to glovebox HA-21I for the hazards analysis performed, glovebox HC-21C is sufficiently similar that the following analysis is also valid for HC-21C. This hazards analysis document is being re-released as revision 1 to include the updated flowsheet document (Appendix C) and the updated design basis (Appendix D). The revised Process Flow Schematic has also been included (Appendix E). This Current revision incorporates the recommendations provided from the original hazards analysis as well. The System Design Description (SDD) has also been appended (Appendix H) to document the bases for Safety Classification of thermal stabilization equipment

  18. Mechanism for microstructural evolution induced by high temperature deformation in Zr-based bulk metallic glasses

    International Nuclear Information System (INIS)

    Cheng, Sirui; Wang, Chunju; Ma, Mingzhen; Shan, Debin; Guo, Bin

    2016-01-01

    In the Zr_4_1_._2Ti_1_3_._8Cu_1_2_._5Ni_1_0Be_2_2_._5 (Vit1) alloy undergoing high temperature deformation, its thermal properties and microstructure are quite different from those in the annealing alloy. In order to research the coupled effect of temperature and plastic strain on microstructural evolution of Zr-based amorphous, uniaxial compression test of Vit1 alloy with good amorphous nature has been performed, and then the structural state and thermal properties of Vit1 alloy after thermal deformation and isothermal annealing in the supercooled liquid region were investigated. It is revealed that the deformed specimens possess higher characteristic temperature and lower enthalpy change of microstructural relaxation. In addition, the smaller inter-atomic distance and higher order degree of atomic arrangement can be observed in those deformed Vit1 alloy. That can be deduced that thermal deformation is in favor of the microstructural evolution from a metastable amorphous state to stable crystallization state, because plastic strain promotes the annihilation of free volume and provide excess driving force of atomic diffusion. However, upon increasing the ambient temperature, the influence of plastic deformation on microstructure gradually decreased owing to the decreasing proportion of the plastic deformation-induced annihilation of free volume during the whole thermal deformation process. - Highlights: • The deformed specimens possess closer microstructure and higher characteristic temperatures. • The order degree of microstructures in deformed specimens is higher than that in annealed specimens. • Thermal deformation accelerates the microstructural evolution of Zr-based BMGs. • The influence of thermal deformation on microstructure decreases with the temperature increasing.

  19. Mechanism for microstructural evolution induced by high temperature deformation in Zr-based bulk metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Sirui [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wang, Chunju [Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080 (China); School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Ma, Mingzhen [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Shan, Debin, E-mail: shandebin@hit.edu.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080 (China); School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Guo, Bin [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2016-08-15

    In the Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5} (Vit1) alloy undergoing high temperature deformation, its thermal properties and microstructure are quite different from those in the annealing alloy. In order to research the coupled effect of temperature and plastic strain on microstructural evolution of Zr-based amorphous, uniaxial compression test of Vit1 alloy with good amorphous nature has been performed, and then the structural state and thermal properties of Vit1 alloy after thermal deformation and isothermal annealing in the supercooled liquid region were investigated. It is revealed that the deformed specimens possess higher characteristic temperature and lower enthalpy change of microstructural relaxation. In addition, the smaller inter-atomic distance and higher order degree of atomic arrangement can be observed in those deformed Vit1 alloy. That can be deduced that thermal deformation is in favor of the microstructural evolution from a metastable amorphous state to stable crystallization state, because plastic strain promotes the annihilation of free volume and provide excess driving force of atomic diffusion. However, upon increasing the ambient temperature, the influence of plastic deformation on microstructure gradually decreased owing to the decreasing proportion of the plastic deformation-induced annihilation of free volume during the whole thermal deformation process. - Highlights: • The deformed specimens possess closer microstructure and higher characteristic temperatures. • The order degree of microstructures in deformed specimens is higher than that in annealed specimens. • Thermal deformation accelerates the microstructural evolution of Zr-based BMGs. • The influence of thermal deformation on microstructure decreases with the temperature increasing.

  20. A Preliminary Experimental Study on Flow Boiling CHF Characteristics of Ballooned Channel

    International Nuclear Information System (INIS)

    Kim, Yong Jin; Song, Sub Lee; Chang, Soon Heung; Moon, Sang Ki

    2013-01-01

    The purpose of this research is to measure heat transfer characteristics experimentally and to develop correlation based on experimental data. Experiments are in progress. The result of preliminary experimental test of ballooned channel was reported. The trends of CHF value for deformed channel is not usual as normal smooth tube. The spot of CHF was moved by changing different experimental cases. The transition of flow pattern at neck of deformation is considered as main factor of changing CHF trends. More cases are under operation and analysis based on flow dynamics are developing. Cladding is one of the most important parts in nuclear power plant because it is second barrier of radiation leakage from nuclear fuel. Originally, cladding keeps its integrity in 1200 .deg. C and 150bar, which is normal operation state of nuclear power plant. However, integrity of cladding can be deformed by more severe conditions caused by accident. In case of LOCA, high temperature, oxidation and thermal shock induced by safety injection can deform cladding. Main problem of deformed cladding is blockage of cooled to prevent core melt accident. Change of flow path by blockage affects flow of safety coolant, heat transfer coefficient and critical heat flux of rod bundles. Until now, there are insufficient heat transfer data for deformed flow path compared to normal flow path. In order to enhance safety of nuclear power plant after accident, it should be clarified that how deformed cladding affects heat transfer

  1. Adaptive radiation along a thermal gradient: preliminary results of habitat use and respiration rate divergence among whitefish morphs.

    Directory of Open Access Journals (Sweden)

    Kimmo Kalevi Kahilainen

    Full Text Available Adaptive radiation is considered an important mechanism for the development of new species, but very little is known about the role of thermal adaptation during this process. Such adaptation should be especially important in poikilothermic animals that are often subjected to pronounced seasonal temperature variation that directly affects metabolic function. We conducted a preliminary study of individual lifetime thermal habitat use and respiration rates of four whitefish (Coregonus lavaretus (L. morphs (two pelagic, one littoral and one profundal using stable carbon and oxygen isotope values of otolith carbonate. These morphs, two of which utilized pelagic habitats, one littoral and one profundal recently diverged via adaptive radiation to exploit different major niches in a deep and thermally stratified subarctic lake. We found evidence that the morphs used different thermal niches. The profundal morph had the most distinct thermal niche and consistently occupied the coldest thermal habitat of the lake, whereas differences were less pronounced among the shallow water pelagic and littoral morphs. Our results indicated ontogenetic shifts in thermal niches: juveniles of all whitefish morphs inhabited warmer ambient temperatures than adults. According to sampling of the otolith nucleus, hatching temperatures were higher for benthic compared to pelagic morphs. Estimated respiration rate was the lowest for benthivorous profundal morph, contrasting with the higher values estimated for the other morphs that inhabited shallower and warmer water. These preliminary results suggest that physiological adaptation to different thermal habitats shown by the sympatric morphs may play a significant role in maintaining or strengthening niche segregation and divergence in life-history traits, potentially contributing to reproductive isolation and incipient speciation.

  2. Microfabricated thermal modulator for comprehensive two-dimensional micro gas chromatography: design, thermal modeling, and preliminary testing.

    Science.gov (United States)

    Kim, Sung-Jin; Reidy, Shaelah M; Block, Bruce P; Wise, Kensall D; Zellers, Edward T; Kurabayashi, Katsuo

    2010-07-07

    In comprehensive two-dimensional gas chromatography (GC x GC), a modulator is placed at the juncture between two separation columns to focus and re-inject eluting mixture components, thereby enhancing the resolution and the selectivity of analytes. As part of an effort to develop a microGC x microGC prototype, in this report we present the design, fabrication, thermal operation, and initial testing of a two-stage microscale thermal modulator (microTM). The microTM contains two sequential serpentine Pyrex-on-Si microchannels (stages) that cryogenically trap analytes eluting from the first-dimension column and thermally inject them into the second-dimension column in a rapid, programmable manner. For each modulation cycle (typically 5 s for cooling with refrigeration work of 200 J and 100 ms for heating at 10 W), the microTM is kept approximately at -50 degrees C by a solid-state thermoelectric cooling unit placed within a few tens of micrometres of the device, and heated to 250 degrees C at 2800 degrees C s(-1) by integrated resistive microheaters and then cooled back to -50 degrees C at 250 degrees C s(-1). Thermal crosstalk between the two stages is less than 9%. A lumped heat transfer model is used to analyze the device design with respect to the rates of heating and cooling, power dissipation, and inter-stage thermal crosstalk as a function of Pyrex-membrane thickness, air-gap depth, and stage separation distance. Experimental results are in agreement with trends predicted by the model. Preliminary tests using a conventional capillary column interfaced to the microTM demonstrate the capability for enhanced sensitivity and resolution as well as the modulation of a mixture of alkanes.

  3. Calculation of thermal deformations in water-cooled monochromator crystals

    International Nuclear Information System (INIS)

    Nakamura, Ario; Hashimoto, Shinya; Motohashi, Haruhiko

    1994-11-01

    Through calculation of temperature distribution and thermal deformation of monochromators, optical degradation by the heat loads in SPring-8 have been discussed. Cooling experiments were made on three models of copper structures with the JAERI Electron Beam Irradiation Stand (JEBIS) and the results were used to estimate heat transfer coefficients in the models. The heat transfer coefficients have been adopted to simulate heating processes on silicon models of the same structures as the copper models, for which radiations from the SPring-8 bending magnet and the JAERI prototype undulator (WPH-33J) were considered. It has been concluded that, in the case of bending magnet (with power density of 0.27[MW/m 2 ] on monochromator surface), the temperature at the surface center reaches about 30[degC] from the initial temperature of 27[degC] in all the models. In the case of WPH-33J (with power density of 8.2[MW/m 2 ]), the temperature reaches about 200 to 280[degC] depending on the models. The radiation from WPH-33J yields slope errors bigger than the Darwin's width(23[μrad]). (author)

  4. Coupling analysis of frictional heat of fluid film and thermal deformation of mechanical seal end faces

    International Nuclear Information System (INIS)

    Zhou Jianfeng; Gu Boqin

    2007-01-01

    The heat transfer model of the rotating ring and the stationary ring of mechanical seal was built. The method to calculate the frictional heat that transferred by the rings was given. the coupling analysis of the frictional heat of fluid film and thermal deformation of end faces was carried out by using FEA and BP ANN, and the relationship among the rotational speed ω, the fluid film thickness h i on the inner diameter of sealing face and the radial separation angle β of deformed end faces was obtained. Corresponding to a given ω, h i and β can be obtained by the equilibrium condition between the closing force and the bearing force of fluid film. The relationship between the leakage rate and the closing force was analyzed, and the fundamental of controlling the leakage rate by regulating the closing force was also discussed. (authors)

  5. Thermal exploitation of shallow aquifers. Guide for the preparation of preliminary studies of technical feasibility

    International Nuclear Information System (INIS)

    Ausseur, J.Y.; Sauty, J.P.

    1982-08-01

    This report presents the main devices aimed at exploiting surface aquifers. After an introduction to the different systems of thermal exploitation of aquifers (generalities, very low energy geothermal, sensitive heat storage, interest of thermal exploitation of aquifers, indication of possible systems), this report presents the different possible systems and analyses their characteristics and performance. These systems are: direct exploitation of groundwater bodies at their natural temperature by heat sink and with release in surface networks or by geothermal dipole, or exploitation with artificial thermal refill. Thus the report addresses the single sink device with or without storage, heat pumps on dipole in surface groundwater bodies or very low temperature geothermal, the scanning dipole system, and the dipole system with hot sink and cold sink. It discusses the choice and sizing of the exploitation system. An appendix reports a feasibility preliminary study of nine cases of thermal exploitation of surface aquifers by double drills

  6. Augmentation Rhinoplasty in Cleft Lip Nasal Deformity: Preliminary Patients’ Perspective

    Directory of Open Access Journals (Sweden)

    William H. C. Tiong

    2014-01-01

    Full Text Available The correction of cleft lip nasal deformity is challenging and there have been numerous methods described in the literature with little demonstrated technical superiority of one over another. The common clinical issues associated with cleft lip nasal deformity are its lack of symmetry, alar collapse on the affected side, obtuse nasal labial angle, short nasal length, loss of tip definition, and altered columella show among others. We carried out augmentation of cleft lip rhinoplasties with rib graft in 16 patients over the one-year study period. Each of these patients was reviewed and given questionnaire before and after surgery to evaluate their response on the outcome to the approach. Preoperatively, nasal asymmetry is the main complaint (14/16, 87.5% among our series of patients. Postoperatively, 12 (75% patients out of the 16 reported significant improvement in their nasal symmetry with the other four marginal. All patients reported excellent nasal projection postoperatively with good nasal tip definition. Our series of patients reported overall good satisfaction outcome and will recommend this procedure to other patients with cleft lip nasal deformity. In conclusion, augmentation of cleft lip rhinoplasty can be employed to achieve perceivable and satisfactory outcome in patients with cleft lip nasal deformity.

  7. Analysis of the ballooning deformation of an internally pressurized thin-wall tube during fast thermal transients

    International Nuclear Information System (INIS)

    Lin, E.I.H.

    1977-01-01

    A large-strain time-dependent thermoplastic analysis has been developed for the ballooning deformation of a thin-wall tube subjected to internal pressure, axial loading, and fast thermal transients. This deformation initiates with the onset of plastic instability in the material, the onset being determined by a plastic-instability criterion for strain-rate sensitive materials. The interaction among the local ballooning geometry, the state of stress, and the plastic flow process was considered, and integration of the flow equations yields the local curvature and the states of stress and strain in the vicinity of the maximum ballooning site. The effects of axial constraint and heating rate were also discussed. The analysis was applied to a LWR Zircaloy cladding subjected to a constant heating rate and a range of internal pressures. The results agree very well with experimental strain-time data obtained from tube-burst tests. In most cases, the time of rupture was accurately predicted despite the lack of complete material-property data

  8. Non-thermal plasma instabilities induced by deformation of the electron energy distribution function

    Science.gov (United States)

    Dyatko, N. A.; Kochetov, I. V.; Napartovich, A. P.

    2014-08-01

    Non-thermal plasma is a key component in gas lasers, microelectronics, medical applications, waste gas cleaners, ozone generators, plasma igniters, flame holders, flow control in high-speed aerodynamics and others. A specific feature of non-thermal plasma is its high sensitivity to variations in governing parameters (gas composition, pressure, pulse duration, E/N parameter). This sensitivity is due to complex deformations of the electron energy distribution function (EEDF) shape induced by variations in electric field strength, electron and ion number densities and gas excitation degree. Particular attention in this article is paid to mechanisms of instabilities based on non-linearity of plasma properties for specific conditions: gas composition, steady-state and decaying plasma produced by the electron beam, or by an electric current pulse. The following effects are analyzed: the negative differential electron conductivity; the absolute negative electron mobility; the stepwise changes of plasma properties induced by the EEDF bi-stability; thermo-current instability and the constriction of the glow discharge column in rare gases. Some of these effects were observed experimentally and some of them were theoretically predicted and still wait for experimental confirmation.

  9. Modeling Thermal Pressurization Around Shallow Dikes Using Temperature-Dependent Hydraulic Properties: Implications for Deformation Around Intrusions

    Science.gov (United States)

    Townsend, Meredith R.

    2018-01-01

    Pressurization and flow of groundwater around igneous intrusions depend in part on the hydraulic diffusivity of the host rocks and processes that enhance diffusivity, such as fracturing, or decrease diffusivity, such as mineral precipitation during chemical alteration. Characterizing and quantifying the coupled effects of alteration, pore pressurization, and deformation have significant implications for deformation around intrusions, geothermal energy, contact metamorphism, and heat transfer at mid-ocean ridges. Fractures around dikes at Ship Rock, New Mexico, indicate that pore pressures in the host rocks exceeded hydrostatic conditions by at least 15 MPa following dike emplacement. Hydraulic measurements and petrographic analysis indicate that mineral precipitation clogged the pores of the host rock, reducing porosity from 0.25 to reducing permeability by 5 orders of magnitude. Field data from Ship Rock are used to motivate and constrain numerical models for thermal pore fluid pressurization adjacent to a meter-scale dike, using temperature-dependent hydraulic properties in the host rock as a proxy for porosity loss by mineral precipitation during chemical alteration. Reduction in permeability by chemical alteration has a negligible effect on pressurization. However, reduction in porosity by mineral precipitation increases fluid pressure by constricting pore volume and is identified as a potentially significant source of pressure. A scaling relationship is derived to determine when porosity loss becomes important; if permeability is low enough, pressurization by porosity loss outweighs pressurization by thermal expansion of fluids.

  10. Structural properties, deformation behavior and thermal stability of martensitic Ti-Nb alloys

    Energy Technology Data Exchange (ETDEWEB)

    Boenisch, Matthias

    2016-06-10

    Ti-Nb alloys are characterized by a diverse metallurgy which allows obtaining a wide palette of microstructural configurations and physical properties via careful selection of chemical composition, heat treatment and mechanical processing routes. The present work aims to expand the current state of knowledge about martensite forming Ti-Nb alloys by studying 15 binary Ti-c{sub Nb}Nb (9 wt.% ≤ c{sub Nb} ≤ 44.5 wt.%) alloy formulations in terms of their structural and mechanical properties, as well as their thermal stability. The crystal structures of the martensitic phases, α{sup '} and α'', and the influence of the Nb content on the lattice (Bain) strain and on the volume change related to the β → α{sup '}/α'' martensitic transformations are analyzed on the basis of Rietveld-refinements. The magnitude of the shuffle component of the β → α{sup '}/α'' martensitic transformations is quantified in relation to the chemical composition. The largest transformation lattice strains are operative in Nb-lean alloys. Depending on the composition, both a volume dilatation and contraction are encountered and the volume change may influence whether hexagonal martensite α{sup '} or orthorhombic martensite α'' forms from β upon quenching. The mechanical properties and the deformation behavior of martensitic Ti-Nb alloys are studied by complementary methods including monotonic and cyclic uniaxial compression, nanoindentation, microhardness and impulse excitation technique. The results show that the Nb content strongly influences the mechanical properties of martensitic Ti-Nb alloys. The elastic moduli, hardness and strength are minimal in the vicinity of the limiting compositions bounding the interval in which orthorhombic martensite α'' forms by quenching. Uniaxial cyclic compressive testing demonstrates that the elastic properties of strained samples are different than those of unstrained ones

  11. Influences of thermal deformation of cavity mirrors induced by high energy DF laser to beam quality under the simulated real physical circumstances

    Science.gov (United States)

    Deng, Shaoyong; Zhang, Shiqiang; He, Minbo; Zhang, Zheng; Guan, Xiaowei

    2017-05-01

    The positive-branch confocal unstable resonator with inhomogeneous gain medium was studied for the normal used high energy DF laser system. The fast changing process of the resonator's eigenmodes was coupled with the slow changing process of the thermal deformation of cavity mirrors. Influences of the thermal deformation of cavity mirrors to the outcoupled beam quality and transmission loss of high frequency components of high energy laser were computed. The simulations are done through programs compiled by MATLAB and GLAD software and the method of combination of finite elements and Fox-li iteration algorithm was used. Effects of thermal distortion, misaligned of cavity mirrors and inhomogeneous distribution of gain medium were introduced to simulate the real physical circumstances of laser cavity. The wavefront distribution and beam quality (including RMS of wavefront, power in the bucket, Strehl ratio, diffraction limit β, position of the beam spot center, spot size and intensity distribution in far-field ) of the distorted outcoupled beam were studied. The conclusions of the simulation agree with the experimental results. This work would supply references of wavefront correction range to the adaptive optics system of interior alleyway.

  12. SolarOil Project, Phase I preliminary design report. [Solar Thermal Enhanced Oil Recovery project

    Energy Technology Data Exchange (ETDEWEB)

    Baccaglini, G.; Bass, J.; Neill, J.; Nicolayeff, V.; Openshaw, F.

    1980-03-01

    The preliminary design of the Solar Thermal Enhanced Oil Recovery (SolarOil) Plant is described in this document. This plant is designed to demonstrate that using solar thermal energy is technically feasible and economically viable in enhanced oil recovery (EOR). The SolarOil Plant uses the fixed mirror solar concentrator (FMSC) to heat high thermal capacity oil (MCS-2046) to 322/sup 0/C (611/sup 0/F). The hot fluid is pumped from a hot oil storage tank (20 min capacity) through a once-through steam generator which produces 4.8 MPa (700 psi) steam at 80% quality. The plant net output, averaged over 24 hr/day for 365 days/yr, is equivalent to that of a 2.4 MW (8.33 x 10/sup 6/ Btu/hr) oil-fired steam generator having an 86% availability. The net plant efficiency is 57.3% at equinox noon, a 30%/yr average. The plant will be demonstrated at an oilfield site near Oildale, California.

  13. Relationships between stratigraphy, deformation and thermal history in sedimentary basins. Impact of geodynamic concepts in petroleum exploration

    International Nuclear Information System (INIS)

    Sarmiento, Luis Fernando

    2002-01-01

    The natural processes that generate petroleum accumulations in a sedimentary basin require several ingredients: (1) the petroleum system elements: source, reservoir, seal and overburden rocks, which are the result of sedimentation processes in a subsiding basin; (2) petroleum traps, which in many cases are the result of deformation and (3) heat to convert suitable organic matter into petroleum. Although these different phenomena are considered independent at the scale of an oil field, at the lithosphere scale thermal phenomena, (2) vertical movements of the earth surface responsible for sedimentation and erosion and (3) tectonic deformation are not independent phenomena, physical quantitative laws intimately relate them. These mutual inter relationships are useful in petroleum exploration to predict one factor having knowledge of the others. Applications of these concepts can contribute to understand the tectonic history of complex areas, such as the Colombian sedimentary basins and reduce exploration risk

  14. Preliminary thermal-hydraulic and structural strength analyses for pre-moderator of cold moderator

    International Nuclear Information System (INIS)

    Aso, Tomokazu; Kaminaga, Masanori; Terada, Atsuhiko; Hino, Ryutaro

    2001-08-01

    A light-water cooled pre-moderator with a thin-walled structure made of aluminum alloy is installed around a liquid hydrogen moderator in order to enhance the neutron performance of a MW-scale spallation target system which is being developed in the Japan Atomic Energy Research Institute (JAERI). Since the pre-moderator is needed to be located close to a target working as a neutron source, it is indispensable to remove nuclear heat deposition in the pre-moderator effectively by means of smooth water flow without flow stagnation. Also, the structural integrity of the thin-walled structure should be kept against the water pressure. Preliminary thermal-hydraulic analytical results showed that the water temperature rise could be suppressed less than 1degC while keeping the smooth water flow, which would assure the expected neutron performance. As for the structural integrity, several measures to meet allowable stress conditions of aluminum alloy were proposed on the basis of the preliminary structural strength analyses. (author)

  15. The deformation analysis of the KALIMER breakeven core driver fuel pin based on the axial power profile during irradiation

    International Nuclear Information System (INIS)

    Lee, Dong Uk; Lee, Byoung Oon; Kim, Young Kyun; Hong, Ser Gi; Chang, Jin Wook; Lee, Ki Bok; Kim, Young Il

    2003-03-01

    In this study, material properties such as coolant specific heat, film heat transfer coefficient, cladding thermal conductivity, surface diffusion coefficient of the multi-bubble are improved in MACSIS-Mod1. The axial power and flux profile module was also incorporated with irradiation history. The performance and feasibility of the driver fuel pin have been analyzed for nominal parameters based on the conceptual design for the KALIMER breakeven core by MACSIS-MOD1 code. The fuel slug centerline temperature takes the maximum at 700mm from the bottom of the slug in spite of the nearly symmetric axial power distribution. The cladding mid-wall and coolant temperatures take the maximum at the top of the pin. Temperature of the fuel slug surface over the entire irradiation life is much lower than the fuel-clad eutectic reaction temperature. The fission gas release of the driver fuel pin at the End Of Life(EOL) is predicted to be 68.61% and plenum pressure is too low to cause cladding yielding. The probability that the fuel pin would fail is estimated to be much less than that allowed in the design criteria. The maximum radial deformation of the fuel pin is 1.928%, satisfying the preliminary design criterion (3%) for fuel pin deformation. Therefore the conceptual design parameters of the driver fuel pin for the KALIMER breakeven core are expected to satisfy the preliminary criteria on temperature, fluence limit, deformation limit etc

  16. The deformation analysis of the KALIMER breakeven core driver fuel pin based on the axial power profile during irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Uk; Lee, Byoung Oon; Kim, Young Kyun; Hong, Ser Gi; Chang, Jin Wook; Lee, Ki Bok; Kim, Young Il

    2003-03-01

    In this study, material properties such as coolant specific heat, film heat transfer coefficient, cladding thermal conductivity, surface diffusion coefficient of the multi-bubble are improved in MACSIS-Mod1. The axial power and flux profile module was also incorporated with irradiation history. The performance and feasibility of the driver fuel pin have been analyzed for nominal parameters based on the conceptual design for the KALIMER breakeven core by MACSIS-MOD1 code. The fuel slug centerline temperature takes the maximum at 700mm from the bottom of the slug in spite of the nearly symmetric axial power distribution. The cladding mid-wall and coolant temperatures take the maximum at the top of the pin. Temperature of the fuel slug surface over the entire irradiation life is much lower than the fuel-clad eutectic reaction temperature. The fission gas release of the driver fuel pin at the End Of Life(EOL) is predicted to be 68.61% and plenum pressure is too low to cause cladding yielding. The probability that the fuel pin would fail is estimated to be much less than that allowed in the design criteria. The maximum radial deformation of the fuel pin is 1.928%, satisfying the preliminary design criterion (3%) for fuel pin deformation. Therefore the conceptual design parameters of the driver fuel pin for the KALIMER breakeven core are expected to satisfy the preliminary criteria on temperature, fluence limit, deformation limit etc.

  17. Simulating the swelling and deformation behaviour in soft tissues using a convective thermal analogy

    Directory of Open Access Journals (Sweden)

    Herzog Walter

    2002-12-01

    Full Text Available Abstract Background It is generally accepted that cartilage adaptation and degeneration are mechanically mediated. Investigating the swelling behaviour of cartilage is important because the stress and strain state of cartilage is associated with the swelling and deformation behaviour. It is well accepted that the swelling of soft tissues is associated with mechanical, chemical, and electrical events. Method The purpose of the present study was to implement the triphasic theory into a commercial finite element tool (ABAQUS to solve practical problems in cartilage mechanics. Because of the mathematical identity between thermal and mass diffusion processes, the triphasic model was transferred into a convective thermal diffusion process in the commercial finite element software. The problem was solved using an iterative procedure. Results The proposed approach was validated using the one-dimensional numerical solutions and the experimental results of confined compression of articular cartilage described in the literature. The time-history of the force response of a cartilage specimen in confined compression, which was subjected to swelling caused by a sudden change of saline concentration, was predicted using the proposed approach and compared with the published experimental data. Conclusion The advantage of the proposed thermal analogy technique over previous studies is that it accounts for the convective diffusion of ion concentrations and the Donnan osmotic pressure in the interstitial fluid.

  18. Modeling and preliminary thermal analysis of the capsule for a creep test in HANARO

    International Nuclear Information System (INIS)

    Choi, Myoung Hwan; Cho, Man Soon; Choo, Kee Nam; Kang, Young Hwan; Sohn, Jae Min; Shin, Yoon Taeg; Park, Sung Jae; Kim, Bong Goo; Kim, Young Jin

    2005-01-01

    A creep capsule is a device to investigate the creep characteristics of nuclear materials during inpile irradiation tests. To obtain the design data of the capsule through a preliminary thermal analysis, a 2-dimensional model for the cross section of the capsule including the specimens and components is generated, and an analysis using the ANSYS program is performed. The gamma-heating rates of the materials for the HANARO power of 30MW are considered, and the effect of the gap size and the control rod position on the temperature of the specimen is discussed. From the analysis it is found that the gap between the thermal media and the external tube has a significant effect on the temperature of the specimen. The temperature by increasing the position of the control rod is decreased

  19. Effects of deformability and thermal motion of lipid membrane on electroporation: By molecular dynamics simulations

    International Nuclear Information System (INIS)

    Sun, Sheng; Yin, Guangyao; Lee, Yi-Kuen; Wong, Joseph T.Y.; Zhang, Tong-Yi

    2011-01-01

    Research highlights: → MD simulations show that deformability and thermal motion of membrane affect electroporation. → Stiffer membrane inhibits electroporation and makes water penetrate from both sides. → Higher temperature accelerates electroporation. -- Abstract: Effects of mechanical properties and thermal motion of POPE lipid membrane on electroporation were studied by molecular dynamics simulations. Among simulations in which specific atoms of lipids were artificially constrained at their equilibrium positions using a spring with force constant of 2.0 kcal/(mol A 2 ) in the external electric field of 1.4 kcal/(mol A e), only constraint on lateral motions of lipid tails prohibited electroporation while non-tail parts had little effects. When force constant decreased to 0.2 kcal/(mol A 2 ) in the position constraints on lipid tails in the external electric field of 2.0 kcal/(mol A e), water molecules began to enter the membrane. Position constraints of lipid tails allow water to penetrate from both sides of membrane. Thermal motion of lipids can induce initial defects in the hydrophobic core of membrane, which are favorable nucleation sites for electroporation. Simulations at different temperatures revealed that as the temperature increases, the time taken to the initial pore formation will decrease.

  20. Effects of superplastic deformations on thermophysical properties of tetragonal zirconia polycrystals

    International Nuclear Information System (INIS)

    Motohashi, Y.; Wan, C.; Sakuma, T.; Harjo, S.; Shibata, T.; Ishihara, M.; Baba, S.; Hoshiya, T.

    2004-01-01

    Neutron irradiation studies on superplastic zirconia-based ceramics are now in progress as an innovative basic project using the High-temperature Engineering Test Reactor (HTTR) in Japan. The characteristics of the zirconia-based engineering components, made through the formation of superplastic, may be strongly affected by their response to transient or steady-state heat flow. Reliable thermophysical properties such as the coefficients of thermal expansion and thermal conductivity are, therefore, needed to estimate and predict the influence of a high-temperature environment. Accordingly, one of this project's targets is to study the thermophysical properties of superplastic zirconia-based ceramics. The first stage of the research addresses the effects of superplastic deformations on the thermophysical properties of a typical superplastic ceramic, 3 mol% yttria-stabilised tetragonal zirconia polycrystals (3Y-TZP), in its un-irradiated state. First, superplastic tensile deformations were conducted on 3Y-TZP specimens under different conditions in order to obtain specimens with different microstructural characteristics. Afterwards, the following actions were taken: - Specific heat measurements were conducted on the specimens at temperatures ranging from 473 K to 1273 K. - The thermal diffusivity was measured using a laser flash method. The thermal conductivity was then calculated from the measured thermal diffusivity, specific heat and density. - The linear thermal expansion was measured by a push-rod type dilatometer from 300 K to 1473 K. The coefficient of linear thermal expansion (CTE) was estimated from the thermal expansion data. The results obtained from the above measurements are discussed, as is the microstructural evolution caused by the superplastic deformations. It was found that the specific heat was almost independent of microstructural evolution, whereas the thermal diffusivity, thermal conductivity and thermal expansion were quite sensitive to

  1. Low temperature deformation mechanisms in LiF single crystals

    International Nuclear Information System (INIS)

    Fotedar, H.L.; Stroebe, T.G.

    1976-01-01

    An analysis of the deformation behavior of high purity LiF single crystals is given using yielding and work hardening data and thermally activated deformation parameters obtained in the temperature range 77-423 0 K. It is found that while the Fleischer mechanism is apparently valid experimentally over the thermally activated temperature range, vacancies produced in large numbers at 77 0 K could also play a role in determining the critical resolved shear stress at that temperature

  2. Development of an integrated optical coherence tomography-gas nozzle system for surgical laser ablation applications: preliminary findings of in situ spinal cord deformation due to gas flow effects.

    Science.gov (United States)

    Wong, Ronnie; Jivraj, Jamil; Vuong, Barry; Ramjist, Joel; Dinn, Nicole A; Sun, Cuiru; Huang, Yize; Smith, James A; Yang, Victor X D

    2015-01-01

    Gas assisted laser machining of materials is a common practice in the manufacturing industry. Advantages in using gas assistance include reducing the likelihood of flare-ups in flammable materials and clearing away ablated material in the cutting path. Current surgical procedures and research do not take advantage of this and in the case for resecting osseous tissue, gas assisted ablation can help minimize charring and clear away debris from the surgical site. In the context of neurosurgery, the objective is to cut through osseous tissue without damaging the underlying neural structures. Different inert gas flow rates used in laser machining could cause deformations in compliant materials. Complications may arise during surgical procedures if the dura and spinal cord are damaged by these deformations. We present preliminary spinal deformation findings for various gas flow rates by using optical coherence tomography to measure the depression depth at the site of gas delivery.

  3. Deformation at Lava Lake Volcanoes: Lessons from Karthala

    Science.gov (United States)

    Biggs, J.; Rust, A.; Owens, C.

    2014-12-01

    To remain hot, permanent lava lakes require a continuous connection to a magma reservoir. Depending on the state of the conduit, changes in magma pressure could result in changes in the lake level (hydraulic head) or be accommodated elastically leading to surface deformation. Observing deformation is therefore key to understanding the plumbing system associated with lava lakes. However, the majority of the world's lava lakes lie in difficult socio-economic or remote locations meaning that there are few ground-based observations, and it is often necessary to rely on satellite imagery. Karthala volcano experienced a sequence of eruptions in April 2005, Nov 2005, May 2006 and Jan 2007. The first 3 took place at the Choungou Chahale crater, which typically contains either a water or lava lake; the last formed a new pit crater to the north. Satellite thermal imagery (Hirn et al, 2008) does not show an anomaly during the first eruption, which had a phreatomagmatic component, but large thermal anomalies, associated with an ephemeral lava lake were detected during the Nov 2005 and May 2006 eruptions. The final eruption produced a smaller anomaly attributed to a minor lava flow. Here we present InSAR observations from 2004-2010. We find no significant deformation associated with the first three eruptions, but the January 2007 eruption was associated with ~25 cm of deformation near the volcano's summit, characteristic of a dyke intrusion aligned with the northern rift zone. We also observe an unusual pattern deformation along the coast which may be attributed to rapid settling of soft sediment or recent volcanic deposits triggered by seismic activity. We propose that the first eruption cleared the reservoir-summit connection and interacted with the water in Choungou Chahale. The following eruptions formed a lava lake, but without causing deformation. By the final eruption, the conduit had become blocked and magma intruded along the rift zone causing deformation but no

  4. Finite element analysis of large elasto-plastic deformation for sealing ring in nuclear pressure vessel

    International Nuclear Information System (INIS)

    Xiao Xuejian; Chen Ruxin

    1995-02-01

    Based on the R. Hills incremental virtual power principle and the elasto-plastic constitution equation for large deformation and by considering physical nonlinear, geometric nonlinear and thermal effects, a plane and axisymmetric finite element equation for thermal large elasto-plastic deformation has been established in the Euler description. The corresponding analysis program ATLEPD has been also complied for thermal large elasto-plastic deformation process of O-ring in RPV. The variations of stress, strain, contact specific pressure, mesh deformation and the aspects of spring back in upsetting and spring back process have been also investigated. Numerical results are fairly consistent with experimental ones. (5 figs., 4 tabs.)

  5. Thermal expansion absorbing structure for pipeline

    International Nuclear Information System (INIS)

    Nagata, Takashi; Yamashita, Takuya.

    1995-01-01

    A thermal expansion absorbing structure for a pipeline is disposed to the end of pipelines to form a U-shaped cross section connecting a semi-circular torus shell and a short double-walled cylindrical tube. The U-shaped longitudinal cross-section is deformed in accordance with the shrinking deformation of the pipeline and absorbs thermal expansion. Namely, since the central lines of the outer and inner tubes of the double-walled cylindrical tube deform so as to incline, when the pipeline is deformed by thermal expansion, thermal expansion can be absorbed by a simple configuration thereby enabling to contribute to ensure the safety. Then, the entire length of the pipeline can greatly be shortened by applying it to the pipeline disposed in a high temperature state compared with a method of laying around a pipeline using only elbows, which has been conducted so far. Especially, when it is applied to a pipeline for an FBR-type reactor, the cost for the construction of a facility of a primary systems can greater be reduced. In addition, it can be applied to a pipeline for usual chemical plants and any other structures requiring absorption of deformation. (N.H.)

  6. Influence of thermally activated processes on the deformation behavior during low temperature ECAP

    Science.gov (United States)

    Fritsch, S.; Scholze, M.; F-X Wagner, M.

    2016-03-01

    High strength aluminum alloys are generally hard to deform. Therefore, the application of conventional severe plastic deformation methods to generate ultrafine-grained microstructures and to further increase strength is considerably limited. In this study, we consider low temperature deformation in a custom-built, cooled equal channel angular pressing (ECAP) tool (internal angle 90°) as an alternative approach to severely plastically deform a 7075 aluminum alloy. To document the maximum improvement of mechanical properties, these alloys are initially deformed from a solid solution heat-treated condition. We characterize the mechanical behavior and the microstructure of the coarse grained initial material at different low temperatures, and we analyze how a tendency for the PLC effect and the strain-hardening rate affect the formability during subsequent severe plastic deformation at low temperatures. We then discuss how the deformation temperature and velocity influence the occurrence of PLC effects and the homogeneity of the deformed ECAP billets. Besides the mechanical properties and these microstructural changes, we discuss technologically relevant processing parameters (such as pressing forces) and practical limitations, as well as changes in fracture behavior of the low temperature deformed materials as a function of deformation temperature.

  7. Study of deformation mechanisms of zinc bicrystals by thermal cycling (1963); Etude des mecanismes de deformation par cyclage thermique de bicristaux de zinc (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Mondon, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1963-06-15

    The thermal cycling of zinc bicrystals has been studied in order to precise the thermal cycling growth mechanism, proposed by Burke and TURKALO, specially the dependence of 'equi-cohesive' temperature of grains on their mutual orientation and the parameters of the thermal cycle. Dilatometric studies showed that a bicrystal had no equi-cohesive temperature and that the grain-boundary develops stress at all temperatures. The creep of single and bicrystal have been studied on a dilatometer with stress below the Yield-stress. At constant temperature secondary creep appears after a transient period, at cycled temperature creep stays transient for strains of about 10{sup -4} to 10{sup -3} when the crystal is plastically hard. Micrographic investigations show that grain-boundary migration accompanies the grain boundary shearing and that cycles produce a strong polygonisation, corroborating the fact that the grain boundary remains a stress-generator and that creep occurs in the volume of grains. The discussion of results shows that the transient creep of hard grain in a bicrystal makes the thermal cycling irreversible and allows on elongation at each cycle if that have the lower expansion coefficient. (author) [French] Le cyclage thermique de bicristaux de zinc a ete etudie pour preciser le mecanisme de la croissance au cyclage thermique propose par BURKE et TURKALO, notamment la temperature d' 'equicohesion' des grains en fonction de leur orientation mutuelle et du regime de cyclage impose. Des essais dilatometriques ont montre qu'un bicristal ne presentait pas de temperature d'equicohesion et que le joint exercait des contraintes quelle que soit la temperature superieure du cycle. Le fluage de monocristaux et de bicristaux a ete etudie sur un dilatometre avec des contraintes inferieures a la limite elastique. A temperature constante le fluage secondaire apparait apres une periode transitoire, a temperature cyclee le fluage reste transitoire pour des deformations de l

  8. Multi-dimensional SAR tomography for monitoring the deformation of newly built concrete buildings

    Science.gov (United States)

    Ma, Peifeng; Lin, Hui; Lan, Hengxing; Chen, Fulong

    2015-08-01

    Deformation often occurs in buildings at early ages, and the constant inspection of deformation is of significant importance to discover possible cracking and avoid wall failure. This paper exploits the multi-dimensional SAR tomography technique to monitor the deformation performances of two newly built buildings (B1 and B2) with a special focus on the effects of concrete creep and shrinkage. To separate the nonlinear thermal expansion from total deformations, the extended 4-D SAR technique is exploited. The thermal map estimated from 44 TerraSAR-X images demonstrates that the derived thermal amplitude is highly related to the building height due to the upward accumulative effect of thermal expansion. The linear deformation velocity map reveals that B1 is subject to settlement during the construction period, in addition, the creep and shrinkage of B1 lead to wall shortening that is a height-dependent movement in the downward direction, and the asymmetrical creep of B2 triggers wall deflection that is a height-dependent movement in the deflection direction. It is also validated that the extended 4-D SAR can rectify the bias of estimated wall shortening and wall deflection by 4-D SAR.

  9. Role of grain refinement in hardening of structural steels at preliminary thermomechanical treatment

    International Nuclear Information System (INIS)

    Bukhvalov, A.B.; Grigor'eva, E.V.; Davydova, L.S.; Degtyarev, M.V.; Levit, V.I.; Smirnova, N.A.; Smirnov, L.V.

    1981-01-01

    The hardening mechanism during preliminary thermomechanical treatment with deformation by cold rolling or hydroextrusion is studied on structural 37KhN3M1 and 38KhN3MFA steels. Specimens have been tested on static tension, impact strength and fracture toughness. It is shown that hydroextrusion application instead of rolling does not change the hardening effect of preliminary thermomechanical treatment (PTMT). It is established that the increase of preliminary deformation degree and the use of accelerated short term hardening heating provides a bett er grain refinement and the increase of PTMT hardening effect [ru

  10. Deformation Analysis of the Main Components in a Single Screw Compressor

    Science.gov (United States)

    Liu, Feilong; Liao, Xueli; Feng, Quanke; Van Den Broek, Martijn; De Paepe, Michel

    2015-08-01

    The single screw compressor is used in many fields such as air compression, chemical industry and refrigeration. During operation, different gas pressures and temperatures applied on the components can cause different degrees of deformation, which leads to a difference between the thermally induced clearance and the designed clearance. However, limited research about clearance design is reported. In this paper, a temperature measurement instrument and a convective heat transfer model were described and used to establish the temperature of a single screw air compressor's casing, screw rotor and star wheel. 3-D models of these three main components were built. The gas force deformation, thermal- structure deformation and thermal-force coupling deformation were carried out by using a finite element simulation method. Results show that the clearance between the bottom of the groove and the top of star wheel is reduced by 0.066 mm, the clearance between the side of groove and the star wheel is reduced by 0.015 mm, and the clearance between the cylinder and the rotor is reduced by 0.01 mm. It is suggested that these deformations should be taken into account during the design of these clearances.

  11. A nonlocal strain gradient model for dynamic deformation of orthotropic viscoelastic graphene sheets under time harmonic thermal load

    Science.gov (United States)

    Radwan, Ahmed F.; Sobhy, Mohammed

    2018-06-01

    This work presents a nonlocal strain gradient theory for the dynamic deformation response of a single-layered graphene sheet (SLGS) on a viscoelastic foundation and subjected to a time harmonic thermal load for various boundary conditions. Material of graphene sheets is presumed to be orthotropic and viscoelastic. The viscoelastic foundation is modeled as Kelvin-Voigt's pattern. Based on the two-unknown plate theory, the motion equations are obtained from the dynamic version of the virtual work principle. The nonlocal strain gradient theory is established from Eringen nonlocal and strain gradient theories, therefore, it contains two material scale parameters, which are nonlocal parameter and gradient coefficient. These scale parameters have two different effects on the graphene sheets. The obtained deflection is compared with that predicted in the literature. Additional numerical examples are introduced to illustrate the influences of the two length scale coefficients and other parameters on the dynamic deformation of the viscoelastic graphene sheets.

  12. Preliminary tension effect on low-cycle fatigue of 40Kh13 steel in gaseous hydrogen

    International Nuclear Information System (INIS)

    Romaniv, A.N.

    1984-01-01

    Comparative bending tests of specimens deformed by tension at 65, 18 and 30% in hydrogen and vacuum were accomplished to reveal the effect of preliminary tension on low-cycle fatigue strength of 40Kh13 martensitic steel. It was found that small amounts of preliminary strains induced a considerable decrease in low-cycle durability in vacuum and hydrogen which was connected with developing defects arising at the early stages of plastic deformation. A rather high degree of preliminary tension promoted steel homogenization, hydrogen embrittlement decrease and service behaviour improvement

  13. Discrete Surface Evolution and Mesh Deformation for Aircraft Icing Applications

    Science.gov (United States)

    Thompson, David; Tong, Xiaoling; Arnoldus, Qiuhan; Collins, Eric; McLaurin, David; Luke, Edward; Bidwell, Colin S.

    2013-01-01

    Robust, automated mesh generation for problems with deforming geometries, such as ice accreting on aerodynamic surfaces, remains a challenging problem. Here we describe a technique to deform a discrete surface as it evolves due to the accretion of ice. The surface evolution algorithm is based on a smoothed, face-offsetting approach. We also describe a fast algebraic technique to propagate the computed surface deformations into the surrounding volume mesh while maintaining geometric mesh quality. Preliminary results presented here demonstrate the ecacy of the approach for a sphere with a prescribed accretion rate, a rime ice accretion, and a more complex glaze ice accretion.

  14. Deformation twinning: Influence of strain rate

    Energy Technology Data Exchange (ETDEWEB)

    Gray, G.T. III

    1993-11-01

    Twins in most crystal structures, including advanced materials such as intermetallics, form more readily as the temperature of deformation is decreased or the rate of deformation is increased. Both parameters lead to the suppression of thermally-activated dislocation processes which can result in stresses high enough to nucleate and grow deformation twins. Under high-strain rate or shock-loading/impact conditions deformation twinning is observed to be promoted even in high stacking fault energy FCC metals and alloys, composites, and ordered intermetallics which normally do not readily deform via twinning. Under such conditions and in particular under the extreme loading rates typical of shock wave deformation the competition between slip and deformation twinning can be examined in detail. In this paper, examples of deformation twinning in the intermetallics TiAl, Ti-48Al-lV and Ni{sub 3}A as well in the cermet Al-B{sub 4}C as a function of strain rate will be presented. Discussion includes: (1) the microstructural and experimental variables influencing twin formation in these systems and twinning topics related to high-strain-rate loading, (2) the high velocity of twin formation, and (3) the influence of deformation twinning on the constitutive response of advanced materials.

  15. Thermal Microstructural Stability of AZ31 Magnesium after Severe Plastic Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Young, John P.; Askari, Hesam A.; Hovanski, Yuri; Heiden, Michael J.; Field, David P.

    2015-03-01

    Both equal channel angular pressing and friction stir processing have the ability to refine the grain size of twin roll cast AZ31 magnesium and potentially improve its superplastic properties. This work used isochronal and isothermal heat treatments to investigate the microstructural stability of twin roll cast, equal channel angular pressed and friction stir processed AZ31 magnesium. For both heat treatment conditions, it was found that the twin roll casted and equal channel angular pressed materials were more stable than the friction stir processed material. Calculations of the grain growth kinetics showed that severe plastic deformation processing decreased the activation energy for grain boundary motion with the equal channel angular pressed material having the greatest Q value of the severely plastically deformed materials and that increasing the tool travel speed of the friction stir processed material improved microstructural stability. The Hollomon-Jaffe parameter was found to be an accurate means of identifying the annealing conditions that will result in substantial grain growth and loss of potential superplastic properties in the severely plastically deformed materials. In addition, Humphreys’s model of cellular microstructural stability accurately predicted the relative microstructural stability of the severely plastically deformed materials and with some modification, closely predicted the maximum grain size ratio achieved by the severely plastically deformed materials.

  16. Thermoelastoplastic Deformation of a Multilayer Ball

    Science.gov (United States)

    Murashkin, E. V.; Dats, E. P.

    2017-09-01

    The problem of centrally symmetric deformation of a multilayer elastoplastic ball in the process of successive accretion of preheated layers to its outer surface is considered in the framework of small elastoplastic deformations. The problems of residual stress formation in the elastoplastic ball with an inclusion and a cavity are solved under various mechanical boundary conditions on the inner surface and for prescribed thermal compression distributions. The graphs of residual stress and displacement fields are constructed.

  17. Study beryllium microplastic deformation

    International Nuclear Information System (INIS)

    Papirov, I.I.; Ivantsov, V.I.; Nikolaenko, A.A.; Shokurov, V.S.; Tuzov, Yu.V.

    2015-01-01

    Microplastic flow characteristics systematically studied for different varieties beryllium. In isostatically pressed beryllium it decreased with increasing particle size of the powder, increasing temperature and increasing the pressing metal purity. High initial values of the limit microelasticity and microflow in some cases are due a high level of internal stresses of thermal origin and over time it can relax slowly. During long-term storage of beryllium materials with high initial resistance values microplastic deformation microflow limit and microflow stress markedly reduced, due mainly to the relaxation of thermal microstrain

  18. Deformation mechanism of the Cryostat in the CADS Injector II

    Science.gov (United States)

    Yuan, Jiandong; Zhang, Bin; Wan, Yuqin; Sun, Guozhen; Bai, Feng; Zhang, Juihui; He, Yuan

    2018-01-01

    Thermal contraction and expansion of the Cryostat will affect its reliability and stability. To optimize and upgrade the Cryostat, we analyzed the heat transfer in a cryo-vacuum environment from the theoretical point first. The simulation of cryo-vacuum deformation based on a finite element method was implemented respectively. The completed measurement based on a Laser Tracker and a Micro Alignment Telescope was conducted to verify its correctness. The monitored deformations were consistent with the simulated ones. After the predictable deformations in vertical direction have been compensated, the superconducting solenoids and Half Wave Resonator cavities approached the ideal "zero" position under liquid helium conditions. These guaranteed the success of 25 MeV@170 uA continuous wave protons of Chinese accelerator driven subcritical system Injector II. By correlating the vacuum and cryo-deformation, we have demonstrated that the complete deformation was the superposition effect of the atmospheric pressure, gravity and thermal stress during both the process of cooling down and warming up. The results will benefit to an optimization for future Cryostat's design.

  19. Effect of Deformation Parameters on Microstructure and Properties During DIFT of X70HD Pipeline Steel

    Science.gov (United States)

    Wang, Jian; Zhu, Wei; Xiao, Hong; Zhang, Liang-liang; Qin, Hao; Yu, Yue

    2018-02-01

    Grain refinement is a critical approach to improve the strength of materials without damaging the toughness. The grains of deformation-induced ferrite are considerably smaller than those of proeutectoid ferrite. Grain refinement is crucial to the application of deformation-induced ferrite. The composition of ferrite and bainite or martensite is important in controlling the performance of X70HD pipeline steel, and cooling significantly influences the control of their ratio and grain size. By analyzing the static and dynamic phase-transition points using Gleeble-3800 thermal simulator, thermal simulations were performed through two-stage deformations in the austenite zone. Ferrite transformation rules were studied with thermal simulation tests under different deformation and cooling parameters based on the actual production of cumulative deformation. The influence of deformation parameters on the microstructure transformation was analyzed. Numerous fine-grain deformation-induced ferrites were obtained by regulating various parameters, including deformation temperature, strain rate, cooling rate, final cooling temperature and other parameters. Results of metallographic observation and microtensile testing revealed that the selection of appropriate parameters can refine the grains and improve the performance of the X70HD pipeline steel.

  20. Stage I surface crack formation in thermal fatigue: A predictive multi-scale approach

    International Nuclear Information System (INIS)

    Osterstock, S.; Robertson, C.; Sauzay, M.; Aubin, V.; Degallaix, S.

    2010-01-01

    A multi-scale numerical model is developed, predicting the formation of stage I cracks, in thermal fatigue loading conditions. The proposed approach comprises 2 distinct calculation steps. Firstly, the number of cycles to micro-crack initiation is determined, in individual grains. The adopted initiation model depends on local stress-strain conditions, relative to sub-grain plasticity, grain orientation and grain deformation incompatibilities. Secondly, 2-4 grains long surface cracks (stage I) is predicted, by accounting for micro-crack coalescence, in 3 dimensions. The method described in this paper is applied to a 500 grains aggregate, loaded in representative thermal fatigue conditions. Preliminary results provide quantitative insight regarding position, density, spacing and orientations of stage I surface cracks and subsequent formation of crack networks. The proposed method is fully deterministic, provided all grain crystallographic orientations and micro-crack linking thresholds are specified. (authors)

  1. Thermal behavior of the Medicina 32-meter radio telescope

    Science.gov (United States)

    Pisanu, Tonino; Buffa, Franco; Morsiani, Marco; Pernechele, Claudio; Poppi, Sergio

    2010-07-01

    We studied the thermal effects on the 32 m diameter radio-telescope managed by the Institute of Radio Astronomy (IRA), Medicina, Bologna, Italy. The preliminary results show that thermal gradients deteriorate the pointing performance of the antenna. Data has been collected by using: a) two inclinometers mounted near the elevation bearing and on the central part of the alidade structure; b) a non contact laser alignment optical system capable of measuring the secondary mirror position; c) twenty thermal sensors mounted on the alidade trusses. Two series of measurements were made, the first series was performed by placing the antenna in stow position, the second series was performed while tracking a circumpolar astronomical source. When the antenna was in stow position we observed a strong correlation between the inclinometer measurements and the differential temperature. The latter was measured with the sensors located on the South and North sides of the alidade, thus indicating that the inclinometers track well the thermal deformation of the alidade. When the antenna pointed at the source we measured: pointing errors, the inclination of the alidade, the temperature of the alidade components and the subreflector position. The pointing errors measured on-source were 15-20 arcsec greater than those measured with the inclinometer.

  2. Determination of the plastic deformation and residual stress tensor distribution using surface and bulk intrinsic magnetic properties

    International Nuclear Information System (INIS)

    Hristoforou, E.; Svec, P. Sr.

    2015-01-01

    We have developed an unique method to provide the stress calibration curve in steels: performing flaw-less welding in the under examination steel, we obtained to determine the level of the local plastic deformation and the residual stress tensors. These properties where measured using both the X-ray and the neutron diffraction techniques, concerning their surface and bulk stresses type II (intra-grain stresses) respectively, as well as the stress tensor type III by using the electron diffraction technique. Measuring the distribution of these residual stresses along the length of a welded sample or structure, resulted in determining the local stresses from the compressive to tensile yield point. Local measurement of the intrinsic surface and bulk magnetic property tensors allowed for the un-hysteretic correlation. The dependence of these local magnetic tensors with the above mentioned local stress tensors, resulting in a unique and almost un-hysteretic stress calibration curve of each grade of steel. This calibration integrated the steel's mechanical and thermal history, as well as the phase transformations and the presence of precipitations occurring during the welding process.Additionally to that, preliminary results in different grade of steels reveal the existence of a universal law concerning the dependence of magnetic and magnetostrictive properties of steels on their plastic deformation and residual stress state, as they have been accumulated due to their mechanical and thermal fatigue and history. This universality is based on the unique dependence of the intrinsic magnetic properties of steels normalized with a certain magnetoelastic factor, upon the plastic deformation or residual stress state, which, in terms, is normalized with their yield point of stress. (authors)

  3. Cold deformation of ADI castings: Martensitic transformation

    International Nuclear Information System (INIS)

    Navea, Lilian R; Mannheim, Rodolfo M; Garin, Jorge L

    2004-01-01

    Research and applications in austempered ductile iron (ADI castings) have recently undergone noticeable progress in the industrialized world, becoming a highly competitive engineering material. The notable properties of these castings derive from their austenitic matrix stabilized by carbon, a thermally stable austenite during the austenizing process but possibly turning into martensite when undergoing plastic deformation. This work aims to study the changing structure of an ADI casting caused by one directional cold lamination. The samples that were studied were obtained from two nodular castings, one without alloying and the other alloyed with Cu, Ni and Mo. The samples were austenized in the first stage of the austempering process at 910 o C for 80 min. Then in the second stage the unalloyed samples were austempered at 410 o C for 10 min and the alloyed samples for 120 min. After the thermal treatment, the test pieces were deformed 0% to 25% by cold lamination. The quantification of the phases was performed using x-ray diffraction and the metallographic study using optic and Scanning Electronic Microscopy. The results show that the martensitic phase obtained by deformation is a very fine structure that evolves into a thicker one when the deformation of the samples increases (CW)

  4. Thermal stability of a highly-deformed warm-rolled tungsten plate in the temperature range 1100–1250 °C

    Energy Technology Data Exchange (ETDEWEB)

    Alfonso, A., E-mail: aalz@dtu.dk [Section of Materials and Surface Engineering, Department of Mechanical Engineering, Technical University of Denmark, 2800 Lyngby (Denmark); Sino-Danish Center for Education and Research, Denmark and China (Denmark); Juul Jensen, D. [Danish-Chinese Center for Nanometals, Section of Materials Science and Advanced Characterization, Department of Wind Energy, Technical University of Denmark, Risø Campus, 4000 Roskilde (Denmark); Sino-Danish Center for Education and Research, Denmark and China (Denmark); Luo, G.-N. [Fusion Reactor Materials Science and Technology Division, Institute of Plasma Physics, Chinese Academy of Sciences, 230031 Hefei, Anhui (China); Sino-Danish Center for Education and Research, Denmark and China (Denmark); Pantleon, W. [Section of Materials and Surface Engineering, Department of Mechanical Engineering, Technical University of Denmark, 2800 Lyngby (Denmark); Association EURATOM-DTU (Denmark); Sino-Danish Center for Education and Research, Denmark and China (Denmark)

    2015-10-15

    Highlights: • Annealing kinetics of highly-deformed tungsten up to 190 h between 1100 °C and 1250 °C. • Loss of mechanical strength characterized by Vickers hardness measurements. • Two distinct stages of recovery and recrystallization identified and described by established models. • Activation energy of recrystallization lower than after moderate deformation of tungsten. • Comparable to activation energy of grain boundary diffusion due to abundance of low angle boundaries. - Abstract: Pure tungsten is considered as armor material for the most critical parts of fusion reactors (i.e. the divertor and the first wall), among other reasons due to its high melting point (3422 °C) and recrystallization temperature. The thermal stability of a pure tungsten plate warm-rolled to a high plastic strain by 90% thickness reduction was investigated by isothermal annealing for up to 190 h in the temperature range between 1100 °C and 1250 °C. Vickers hardness testing allowed tracking the changes in mechanical properties caused by recovery and recrystallization. The hardness evolution could be rationalized in terms of a logarithmic recovery kinetics and a Johnson–Mehl–Avrami–Kolmogorov recrystallization kinetics accounting for an incubation time of recrystallization. The observed time spans for recrystallization and the corresponding recrystallization activation energy for this highly deformed plate suggest that large plastic deformations (e.g. applied during shaping) are only suitable to produce tungsten components to be used at relatively low temperatures (up to 900 °C for a 2 years lifespan). Higher operation temperatures will lead to fast degradation of the microstructure during operation.

  5. Thermal stability of a highly-deformed warm-rolled tungsten plate in the temperature range 1100–1250 °C

    International Nuclear Information System (INIS)

    Alfonso, A.; Juul Jensen, D.; Luo, G.-N.; Pantleon, W.

    2015-01-01

    Highlights: • Annealing kinetics of highly-deformed tungsten up to 190 h between 1100 °C and 1250 °C. • Loss of mechanical strength characterized by Vickers hardness measurements. • Two distinct stages of recovery and recrystallization identified and described by established models. • Activation energy of recrystallization lower than after moderate deformation of tungsten. • Comparable to activation energy of grain boundary diffusion due to abundance of low angle boundaries. - Abstract: Pure tungsten is considered as armor material for the most critical parts of fusion reactors (i.e. the divertor and the first wall), among other reasons due to its high melting point (3422 °C) and recrystallization temperature. The thermal stability of a pure tungsten plate warm-rolled to a high plastic strain by 90% thickness reduction was investigated by isothermal annealing for up to 190 h in the temperature range between 1100 °C and 1250 °C. Vickers hardness testing allowed tracking the changes in mechanical properties caused by recovery and recrystallization. The hardness evolution could be rationalized in terms of a logarithmic recovery kinetics and a Johnson–Mehl–Avrami–Kolmogorov recrystallization kinetics accounting for an incubation time of recrystallization. The observed time spans for recrystallization and the corresponding recrystallization activation energy for this highly deformed plate suggest that large plastic deformations (e.g. applied during shaping) are only suitable to produce tungsten components to be used at relatively low temperatures (up to 900 °C for a 2 years lifespan). Higher operation temperatures will lead to fast degradation of the microstructure during operation.

  6. How deformation enhances mobility in a polymer glass

    Science.gov (United States)

    Lacks, Daniel

    2013-03-01

    Recent experiments show that deformation of a polymer glass can lead to orders-of-magnitude enhancement in the atomic level dynamics. To determine why this change in dynamics occurs, we carry out molecular dynamics simulations and energy landscape analyses. The simulations address the coarse-grained polystyrene model of Kremer and co-workers, and the dynamics, as quantified by the van Hove function, are examined as the glass undergoes shear deformation. In agreement with experiment, the simulations find that deformation enhances the atomic mobility. The enhanced mobility is shown to arise from two mechanisms: First, active deformation continually reduces barriers for hopping events, and the importance of this mechanism is modulated by the rate of thermally activated transitions between adjacent energy minima. Second, deformation moves the system to higher-energy regions of the energy landscape, characterized by lower barriers. Both mechanisms enhance the dynamics during deformation, and the second mechanism is also relevant after deformation has ceased.

  7. Deformation-driven diffusion and plastic flow in amorphous granular pillars.

    Science.gov (United States)

    Li, Wenbin; Rieser, Jennifer M; Liu, Andrea J; Durian, Douglas J; Li, Ju

    2015-06-01

    We report a combined experimental and simulation study of deformation-induced diffusion in compacted quasi-two-dimensional amorphous granular pillars, in which thermal fluctuations play a negligible role. The pillars, consisting of bidisperse cylindrical acetal plastic particles standing upright on a substrate, are deformed uniaxially and quasistatically by a rigid bar moving at a constant speed. The plastic flow and particle rearrangements in the pillars are characterized by computing the best-fit affine transformation strain and nonaffine displacement associated with each particle between two stages of deformation. The nonaffine displacement exhibits exponential crossover from ballistic to diffusive behavior with respect to the cumulative deviatoric strain, indicating that in athermal granular packings, the cumulative deviatoric strain plays the role of time in thermal systems and drives effective particle diffusion. We further study the size-dependent deformation of the granular pillars by simulation, and find that different-sized pillars follow self-similar shape evolution during deformation. In addition, the yield stress of the pillars increases linearly with pillar size. Formation of transient shear lines in the pillars during deformation becomes more evident as pillar size increases. The width of these elementary shear bands is about twice the diameter of a particle, and does not vary with pillar size.

  8. Anisotropic plastic deformation by viscous flow in ion tracks

    NARCIS (Netherlands)

    van Dillen, T; Polman, A; Onck, PR; van der Giessen, E

    2005-01-01

    A model describing the origin of ion beam-induced anisotropic plastic deformation is derived and discussed. It is based on a viscoelastic thermal spike model for viscous flow in single ion tracks derived by Trinkaus and Ryazanov. Deviatoric (shear) stresses, brought about by the rapid thermal

  9. Experiment and simulation on the thermal instability of a heavily deformed Cu-Fe composite

    International Nuclear Information System (INIS)

    Qu Lei; Wang Engang; Zuo Xiaowei; Zhang Lin; He Jicheng

    2011-01-01

    Research highlights: → Fe fibers undergo thermal instability at temperature above 600 deg. C. → Longitudinal boundary splitting is the dominant instability process. → Instability of cylindrical fibers is controlled by breakup, growth and coarsening. → Breakup times can be predicted by Rayleigh perturbation model accurately. → The increase of fiber diameters is due to the coarsening and growth. - Abstract: The thermal instability of the Fe fibers in the heavily deformed Cu-12.8 wt.%Fe composites is investigated experimentally and numerically. The fiber evolution is characterized by a field emission scanning electron microscopy (FESEM). The results show that the dominant instability of the Fe fibers is the longitudinal boundary splitting which is determined by the greater cross sectional aspect ratio (width/thickness, w/t) and the larger ratio of boundary to interfacial energy (γ B /γ S ). The longitudinal boundary splitting makes the ribbon-like Fe fibers evolve into a series of cylindrical fibers. Then the cylindrical Fe fibers undergo the instability process in terms of the breakup, growth and coarsening concurrently. The breakup times are accurately predicted by the Rayleigh perturbation model. The growth process primarily contributes to the higher increasing rate of the fiber radius during isothermal annealing at 700 deg. C than that calculated by the coarsening theory developed for cylindrical fibers, since the Cu-matrix of composites is highly supersaturated after casting/cold-working process.

  10. Non-Fourier based thermal-mechanical tissue damage prediction for thermal ablation.

    Science.gov (United States)

    Li, Xin; Zhong, Yongmin; Smith, Julian; Gu, Chengfan

    2017-01-02

    Prediction of tissue damage under thermal loads plays important role for thermal ablation planning. A new methodology is presented in this paper by combing non-Fourier bio-heat transfer, constitutive elastic mechanics as well as non-rigid motion of dynamics to predict and analyze thermal distribution, thermal-induced mechanical deformation and thermal-mechanical damage of soft tissues under thermal loads. Simulations and comparison analysis demonstrate that the proposed methodology based on the non-Fourier bio-heat transfer can account for the thermal-induced mechanical behaviors of soft tissues and predict tissue thermal damage more accurately than classical Fourier bio-heat transfer based model.

  11. Structure of deformed metals. Struktura deformirovannykh metallov

    Energy Technology Data Exchange (ETDEWEB)

    Bernshtein, M L

    1977-01-01

    A teaching aid for students at metallurgical and machine-building institutions of higher learning. It can also be used by engineering-technical personnel and scientists. A presentation is made of physical concepts on the mechanism of plastic deformation and its effect on fine structure, structure and properties of metals and alloys. An examination is made of the processes of recovery, polygonization and recrystallization during the heating of cold-deformed metals. The influence of thermal deformation is described to account for the interaction between admixture atoms and dislocations, phase and structural transformations. An examination is made of the phenomenon of superplasticity. Special attention is given to the process of hot deformation. An analysis is made of phenomena at the basis of hardening steel as a result of thermo-mechanical processing, including controlled rolling.

  12. Coherent gradient sensing method for measuring thermal stress field of thermal barrier coating structures

    Directory of Open Access Journals (Sweden)

    Kang Ma

    2017-01-01

    Full Text Available Coherent gradient sensing (CGS method can be used to measure the slope of a reflective surface, and has the merits of full-field, non-contact, and real-time measurement. In this study, the thermal stress field of thermal barrier coating (TBC structures is measured by CGS method. Two kinds of powders were sprayed onto Ni-based alloy using a plasma spraying method to obtain two groups of film–substrate specimens. The specimens were then heated with an oxy-acetylene flame. The resulting thermal mismatch between the film and substrate led to out-of-plane deformation of the specimen. The deformation was measured by the reflective CGS method and the thermal stress field of the structure was obtained through calibration with the help of finite element analysis. Both the experiment and numerical results showed that the thermal stress field of TBC structures can be successfully measured by CGS method.

  13. Preliminary degradation process study of infectious biological waste in a 5 k W thermal plasma equipment

    International Nuclear Information System (INIS)

    Xochihua S M, M.C.

    1997-01-01

    This work is a preliminary study of infectious biological waste degradation process by thermal plasma and was made in Thermal Plasma Applications Laboratory of Environmental Studies Department of the National Institute of Nuclear Research (ININ). Infectious biological waste degradation process is realized by using samples such polyethylene, cotton, glass, etc., but the present study scope is to analyze polyethylene degradation process with mass and energy balances involved. Degradation method is realized as follow: a polyethylene sample is put in an appropriated crucible localized inside a pyrolysis reactor chamber, the plasma jet is projected to the sample, by the pyrolysis phenomena the sample is degraded into its constitutive particles: carbon and hydrogen. Air was utilized as a recombination gas in order to obtain the higher percent of CO 2 if amount of O 2 is greater in the recombination gas, the CO generation is reduced. The effluent gases of exhaust pyrolysis reactor through are passed through a heat exchanger to get cooled gases, the temperature water used is 15 Centigrade degrees. Finally the gases was tried into absorption tower with water as an absorbent fluid. Thermal plasma degradation process is a very promising technology, but is necessary to develop engineering process area to avail all advantages of thermal plasma. (Author)

  14. Investigations on fuel can plastic deformations

    International Nuclear Information System (INIS)

    Boutard, J.L.; Dupouy, J.M.

    1979-01-01

    To the extent where the elongation of claddings differs from the mean swelling, the diametral plastic deformation can include, apart from that due to fission gases or the mechanical oxide-cladding interaction, contributions due to swelling prevented along the axis or to growth phenomena. The high thermal activation of the creep of hyper quenched steel unlike cold rolled steel, gives rise to the problem of a contribution to creep in the reactor other than the term SIPA. The impact of mechanisms of diffusion deformation on the boundary decohesion criteria is discussed in conclusion [fr

  15. Effect of cold deformation on latent energy value and high-temperature mechanical properties of 12Cr18Ni10Ti steel

    International Nuclear Information System (INIS)

    Maksimkin, O.P.; Shiganakov, Sh.B.; Gusev, M.N.

    1997-01-01

    Energetic and magnetic characteristics and also the high-temperature mechanical properties depending on the preliminary cold deformation of 12Cr18Ni10Ti steel are presented. It is shown that the value of storage energy in the steel has being grown with increase of the deformation. The rate of its growth has been increased after beginning of martensitic γ→α'- transformation when value of comparative storage energy at first decreased and then has been stay practically constant. Level of mechanical properties of the steel at 1073 K has been determined not only by value of cold deformation but and structural reconstruction corresponding to deformations 35-45% and accompanying with α'-phase martensite formation and change of energy accumulating rate. Preliminary cold deformation (40-60 %) does not improve high- temperature plasticity of steel samples implanted by helium. refs. 7, figs. 2

  16. Modeling of macrosegregation caused by volumetric deformation in a coherent mushy zone

    Science.gov (United States)

    Nicolli, Lilia C.; Mo, Asbjørn; M'hamdi, Mohammed

    2005-02-01

    A two-phase volume-averaged continuum model is presented that quantifies macrosegregation formation during solidification of metallic alloys caused by deformation of the dendritic network and associated melt flow in the coherent part of the mushy zone. Also, the macrosegregation formation associated with the solidification shrinkage (inverse segregation) is taken into account. Based on experimental evidence established elsewhere, volumetric viscoplastic deformation (densification/dilatation) of the coherent dendritic network is included in the model. While the thermomechanical model previously outlined (M. M’Hamdi, A. Mo, and C.L. Martin: Metall. Mater. Trans. A, 2002, vol. 33A, pp. 2081-93) has been used to calculate the temperature and velocity fields associated with the thermally induced deformations and shrinkage driven melt flow, the solute conservation equation including both the liquid and a solid volume-averaged velocity is solved in the present study. In modeling examples, the macrosegregation formation caused by mechanically imposed as well as by thermally induced deformations has been calculated. The modeling results for an Al-4 wt pct Cu alloy indicate that even quite small volumetric strains (≈2 pct), which can be associated with thermally induced deformations, can lead to a macroscopic composition variation in the final casting comparable to that resulting from the solidification shrinkage induced melt flow. These results can be explained by the relatively large volumetric viscoplastic deformation in the coherent mush resulting from the applied constitutive model, as well as the relatively large difference in composition for the studied Al-Cu alloy in the solid and liquid phases at high solid fractions at which the deformation takes place.

  17. Bridge monitoring by interferometric deformation sensors

    Science.gov (United States)

    Inaudi, Daniele; Vurpillot, Samuel; Casanova, Nicoletta

    1996-09-01

    In many concrete bridges, the deformations are the most relevant parameter to be monitored in both short and long- terms. Strain monitoring gives only local information about the material behavior and too many such sensors would therefore be necessary to gain a complete understanding of the bridge behavior. We have found that fiber optic deformation sensors, with measurement bases of the order of one to a few meters, can give useful information both during the first days after concrete pouring and in the long term. In a first phase it is possible to monitor the thermal expansion due to the exothermic setting reaction and successively the thermal and drying shrinkages. Thanks to the long sensor basis, the detection of a crack traverse to the measurement region becomes probable and the evolution of cracks can therefore be followed with a reduced number of sensors. In the long-term it is possible to measure the geometric deformations and therefore the creeping of the bridge under static loads, especially under its own weight. In the past two years, our laboratory has installed hundreds of fiber optic deformation sensors in more than five concrete, composite steel-concrete, refurbished and enlarged bridges (road, highway and railway bridges). The measuring technique relies on low-coherence interferometry and offers a resolution down to a few microns even for long-term measurements. This contribution briefly discusses the measurement technique and then focuses on the development of a reliable sensor for direct concrete embedding and on the experimental results obtained on these bridges.

  18. Liquid Segregation Phenomenological Behaviors of Ti14 Alloy during Semisolid Deformation

    Directory of Open Access Journals (Sweden)

    Y. N. Chen

    2014-05-01

    Full Text Available The liquid segregation phenomenon and its effect on deformation mechanism of Ti14 alloy in semisolid metal processing were investigated by thermal simulation test. Microstructure of depth profile was determined by cross-section quantitative metallography, and liquid segregation phenomenon was described by Darcy's law. The results show that segregation phenomenon was affected by solid fraction, strain rate, and deformation rate. More liquid segregated from center to edge portion with high strain rate and/or deformation ratio as well as low solid fraction, which caused different distribution of dominating deformation mechanism. The relationship between liquid segregation and main deformation mechanism was also discussed by phenomenological model.

  19. Preliminary conceptual design and analysis on KALIMER reactor structures

    International Nuclear Information System (INIS)

    Kim, Jong Bum

    1996-10-01

    The objectives of this study are to perform preliminary conceptual design and structural analyses for KALIMER (Korea Advanced Liquid Metal Reactor) reactor structures to assess the design feasibility and to identify detailed analysis requirements. KALIMER thermal hydraulic system analysis results and neutronic analysis results are not available at present, only-limited preliminary structural analyses have been performed with the assumptions on the thermal loads. The responses of reactor vessel and reactor internal structures were based on the temperature difference of core inlet and outlet and on engineering judgments. Thermal stresses from the assumed temperatures were calculated using ANSYS code through parametric finite element heat transfer and elastic stress analyses. While, based on the results of preliminary conceptual design and structural analyses, the ASME Code limits for the reactor structures were satisfied for the pressure boundary, the needs for inelastic analyses were indicated for evaluation of design adequacy of the support barrel and the thermal liner. To reduce thermal striping effects in the bottom are of UIS due to up-flowing sodium form reactor core, installation of Inconel-718 liner to the bottom area was proposed, and to mitigate thermal shock loads, additional stainless steel liner was also suggested. The design feasibilities of these were validated through simplified preliminary analyses. In conceptual design phase, the implementation of these results will be made for the design of the reactor structures and the reactor internal structures in conjunction with the thermal hydraulic, neutronic, and seismic analyses results. 4 tabs., 24 figs., 4 refs. (Author)

  20. A study of the deformability of composite rods with end fittings for truss structures

    Energy Technology Data Exchange (ETDEWEB)

    Stepanychev, E I; Novikov, V V; Sukhanov, A V; Lapotkin, V A; Postnov, A N [Moskovskii Aviatsionnyi Tekhnologicheskii Institut, Moscow (USSR)

    1989-04-01

    A method is proposed for studying the deformability characteristics of composite rods with end fittings under static loading. Three types of connectors for tubular composite rods are examined from the standpoint of deformability, and differences in the deformability of the central part of a rod and of the connection zone are discussed. The effect of thermal cycling on the deformability of structures of this type is analyzed. 7 refs.

  1. A study on thermal ratcheting structure test of 316L test cylinder

    International Nuclear Information System (INIS)

    Lee, H. Y.; Kim, J. B.; Koo, G. H.

    2001-01-01

    In this study, the progressive inelastic deformation, so called, thermal ratchet phenomenon which can occur in high temperature liquid metal reactor was simulated with thermal ratchet structural test facility and 316L stainless steel test cylinder. The inelastic deformation of the reactor baffle cylinder can occur due to the moving temperature distribution along the axial direction as the hot free surface moves up and down under the cyclic heat-up and cool-down of reactor operations. The ratchet deformations were measured with the laser displacement sensor and LVDTs after cooling the structural specimen which experiences thermal load up to 550 .deg. C and the temperature differences of about 500 .deg. C. During structural thermal ratchet test, the temperature distribution of the test cylinder along the axial direction was measured from 28 channels of thermocouples and the temperatures were used for the ratchet analysis. The thermal ratchet deformation analysis was performed with the NONSTA code whose constitutive model is nonlinear combined kinematic and isotropic hardening model and the test results were compared with those of the analysis. Thermal ratchet test was carried out with respect to 9 cycles of thermal loading and the maximum residual displacements were measured to be 1.8mm. It was shown that thermal ratchet load can cause a progressive deformation to the reactor structure. The analysis results with the combined hardening model were in reasonable agreement with those of the tests

  2. Hot compressive deformation behavior of the as-quenched A357 aluminum alloy

    International Nuclear Information System (INIS)

    Yang, X.W.; Lai, Z.H.; Zhu, J.C.; Liu, Y.; He, D.

    2012-01-01

    Highlights: ► We create a thermal history curve which was applied to carry out compression tests. ► We make an analysis of deformation performance for as-quenched A357 alloy. ► We create a constitutive equation which has good accuracy. - Abstract: The objective of the present work was to establish an accurate thermal-stress mathematical model of the quenching operation for A357 (Al–7Si–0.6Mg) alloy and to investigate the deformation behavior of this alloy. Isothermal compression tests of as-quenched A357 alloy were performed in the temperature range of 350–500 °C and at the strain rate range of 0.001–1 s −1 . Experimental results show that the flow stress of as-quenched A357 alloy decreases with the increase of temperature and the decrease of strain rate. Based on the hyperbolic sine equation, a constitutive equation is a relation between 0.2 pct yield stress and deformation conditions (strain rate and deformation temperature) was established. The corresponding hot deformation activation energy (Q) for as-quenched A357 alloy is 252.095 kJ/mol. Under the different small strains (≤0.01), the constitutive equation parameters of as-quenched A357 alloy were calculated. Values of flow stress calculated by constitutive equation were in a very good agreement with experimental results. Therefore, it can be used as an accurate thermal-stress model to solve the problems of quench distortion of parts.

  3. Non-uniform temperature gradients and thermal stresses produced ...

    Indian Academy of Sciences (India)

    thermally-induced stress distributions in a hollow steel sphere heated by a moving uniform ... models to evaluate temperatures according to the frictional heat generation, ... of these thermal effects include thermal stress, strain and deformation.

  4. Multiscale modeling of large deformations in 3-D polycrystals

    International Nuclear Information System (INIS)

    Lu Jing; Maniatty, Antoinette; Misiolek, Wojciech; Bandar, Alexander

    2004-01-01

    An approach for modeling 3-D polycrystals, linking to the macroscale, is presented. A Potts type model is used to generate a statistically representative grain structures with periodicity to allow scale-linking. The grain structures are compared to experimentally observed grain structures to validate that they are representative. A macroscale model of a compression test is compared against an experimental compression test for an Al-Mg-Si alloy to determine various deformation paths at different locations in the samples. These deformation paths are then applied to the experimental grain structure using a scale-bridging technique. Preliminary results from this work will be presented and discussed

  5. Acoustic emission during tensile deformation of M250 grade maraging steel

    Science.gov (United States)

    Mukhopadhyay, Chandan Kumar; Rajkumar, Kesavan Vadivelu; Chandra Rao, Bhaghi Purna; Jayakumar, Tamanna

    2012-05-01

    Acoustic emission (AE) generated during room temperature tensile deformation of varyingly heat treated (solution annealed and thermally aged) M250 grade maraging steel specimens have been studied. Deformation of microstructure corresponding to different heat treated conditions in this steel could be distinctly characterized using the AE parameters such as RMS voltage, counts and peak amplitude of AE hits (events).

  6. The Clinical Value of Prenatal 3D Ultrasonic Diagnosis on Fetus Hemivertebra Deformity- A Preliminary Study.

    Science.gov (United States)

    Wen, Yanting; Xiang, Guishuang; Liang, Xiaoqiu; Tong, Xiaoqian

    2018-02-01

    The present study is planned to discuss the clinical value of prenatal 3D ultra-sonic diagnosis on fetus hemivertebra deformity through the retrospective analysis of clinical data of fetus hemivertebra deformity. Selected 9 fetus hemivertebra deformity cases, which have been admitted to our hospital during the period from January, 2010 to January, 2016 as study samples, and analyzed their 2D and 3D ultrasonic examination data. 4 cases of the fetus hemivertebra deformity occurred at lumbar vertebra, 3 cases at thoracic vertebra, and 2 cases at thoracolumbar vertebra. There were scoliosis and opened spine bifida (OSB). In 7 cases, there was absence of ribs in fetus. The 2D ultrasonic image showed that: The echo at the center of fetus vertebral arch lesion was blurred or lost. The coronal section showed the deformity of the spine. There was obvious loss of the ossification center. From the cross section, we could see that the vertebral body of the fetus was shrinking and the edges were relatively blurred. The 3D ultrasonic image showed that: the echo at the ossification center of the fetus vertebra was relatively blurred, or even lost. The image also indicated scoliosis deformity of the spine. The vertebral body lesion could be accurately located. 9 cases of fetus hemivertebra deformity have been detected through examination. Labor inductions have been carried out after getting the permission from the family members. The X-ray examination of the fetus after labor induction showed that the diagnosis was correct. Prenatal ultra-sonic examination holds strong potential for the diagnosis of fetus hemivertebra deformity quite early and deserves further clinical evaluation with large sample size.

  7. On The Stress Free Deformation Of Linear FGM Interface Under Constant Temperature

    Directory of Open Access Journals (Sweden)

    Ganczarski Artur

    2015-09-01

    Full Text Available This paper demonstrates the stress free thermo-elastic problem of the FGM thick plate. Existence of such a purely thermal deformation is proved in two ways. First proof is based on application of the Iljushin thermo-elastic potential to displacement type system of equations. This reduces 3D problem to the plane stress state problem. Next it is shown that the unique solution fulfils conditions of simultaneous constant temperature and linear gradation of thermal expansion coefficient. Second proof is based directly on stress type system of equations which straightforwardly reduces to compatibility equations for purely thermal deformation. This occurs if only stress field is homogeneous in domain and at boundary. Finally an example of application to an engineering problem is presented.

  8. Thermal Hydraulic Analysis of K-DEMO Single Blanket Module for Preliminary Accident Analysis using MELCOR

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sung Bo; Bang, In Cheol [UNIST, Ulsan (Korea, Republic of)

    2016-05-15

    To develop the Korean fusion commercial reactor, preliminary design concept for K-DEMO (Korean fusion demonstration reactor) has been announced by NFRI (National Fusion Research Institute). This pre-conceptual study of K-DEMO has been introduced to identify technical details of a fusion power plant for the future commercialization of fusion reactor in Korea. Before this consideration, to build the K-DEMO, accident analysis is essential. Since the Fukushima accident, which is severe accident from unexpected disaster, safety analysis of nuclear power plant has become important. The safety analysis of both fission and fusion reactors is deemed crucial in demonstrating the low radiological effect of these reactors on the environment, during severe accidents. A risk analysis of K-DEMO should be performed, as a prerequisite for the construction of a fusion reactor. In this research, thermal-hydraulic analysis of single blanket module of K-DEMO is conducted for preliminary accident analysis for K-DEMO. Further study about effect of flow distributer is conducted. The normal K-DEMO operation condition is applied to the boundary condition and simulated to verify the material temperature limit using MELCOR. MELCOR is fully integrated, relatively fast-running code developed by Sandia National Laboratories. MELCOR had been used for Light Water Reactors and fusion reactor version of MELCOR was developed for ITER accident analysis. This study shows the result of thermal-hydraulic simulation of single blanket module with MELCOR which is severe accident code for nuclear fusion safety analysis. The difference of mass flow rate for each coolant channel with or without flow distributer is presented. With flow distributer, advantage of broadening temperature gradient in the K-DEMO blanket module and increase mass flow toward first wall is obtained. This can enhance the safety of K-DEMO blanket module. Most 13 .deg. C temperature difference in blanket module is obtained.

  9. Effect of gamma irradiation on thermal inactivation and injury of Bacillus subtilis spores

    International Nuclear Information System (INIS)

    El-Zawahry, Y.A.; Mostafa, S.A.; Awny, N.M.

    1986-01-01

    Bacillus subtilis spores which received preliminary irradiation doses were more sensitive to subsequent heating than non-irradiated spores. The thermal inactivation increased by increasing any of exposure temperature, thermal exposure time or preliminary irradiation dose. The thermal (D T -) value was much higher for non-irradiated spores than the D TR value for the pre-thermal irradiated spores. The radiosensitizing effect was directly proportional to the preliminary irradiation dose. The pre-thermal irradiation treatment of B. subtilis spores resulted in a synergistic effect in spore deactivation. This synergistic effect increased gradually by increasing the preliminary irradiation dose and/or the thermal temperature from 60 to 80 0 C, but decreased for 90 0 C and for the longer exposure periods at any of the examined temperature. Thermal injury of B. subtilis spores was more for the non-irradiated than for the irradiated spores

  10. Analytical and experimental assessment of TVS-2006 fuel assembly thermal-mechanical shape deformation at temperature modeling of a loss-of-coolant accident

    International Nuclear Information System (INIS)

    Afanasiev, A.; Semishkin, V.; Makarov, V.; Matvienko, I.; Puzanov, D.

    2015-01-01

    generated for the consideration of TVS-2006 fuel assembly thermal-mechanical stability and its component shape deformation in loss-of-coolant accidents. The calculation results have shown that in the course of a design-basis loss-of-coolant accident TVS-2006 has a two-fold margin for stability loss at the longitudinal compression considering the increase in the force of FA compression due to thermal expansion of fuel rod bundle. The increase in the width across the flats is insignificant and it does not impede the post-accident core unloading. (authors) KEYWORDS: TVS- 2006, thermal-mechanical, shape deformation, modeling, loss of coolant

  11. GPS observations of coseismic deformation following the May 20 and 29, 2012, Emilia seismic events (northern Italy: data, analysis and preliminary models

    Directory of Open Access Journals (Sweden)

    Enrico Serpelloni

    2012-10-01

    Full Text Available In May-July 2012, a seismic sequence struck a broad area of the Po Plain Region in northern Italy. The sequence included two Ml >5.5 mainshocks. The first one (Ml 5.9 occurred near the city of Finale Emilia (ca. 30 km west of Ferrara on May 20 at 02:03:53 (UTC, and the second (Ml 5.8 occurred on May 29 at 7:00:03 (UTC, about 12 km southwest of the May 20 mainshock (Figure 1, near the city of Mirandola. The seismic sequence involved an area that extended in an E-W direction for more than 50 km, and included seven Ml ≥5.0 events and more than 2,300 Ml >1.5 events (http://iside.rm.ingv.it. The focal mechanisms of the main events [Pondrelli et al. 2012, Scognamiglio et al. 2012, this volume] consistently showed compressional kinematics with E-W oriented reverse nodal planes. This sector of the Po Plain is known as a region characterized by slow deformation rates due to the northwards motion of the northern Apennines fold-and-thrust belt, which is buried beneath the sedimentary cover of the Po Plain [Picotti and Pazzaglia 2008, Toscani et al. 2009]. Early global positioning system (GPS measurements [Serpelloni et al. 2006] and the most recent updates [Devoti et al. 2011, Bennett et al. 2012] recognized that less than 2 mm/yr of SW-NE shortening are accommodated across this sector of the Po Plain, in agreement with other present-day stress indicators [Montone et al. 2012] and known active faults [Basili et al. 2008]. In the present study, we describe the GPS data used to study the coseismic deformation related to the May 20 and 29 mainshocks, and provide preliminary models of the two seismic sources, as inverted from consensus GPS coseismic deformation fields. […

  12. In situ measurement on TSV-Cu deformation with hotplate system based on sheet resistance

    Science.gov (United States)

    Sun, Yunna; Wang, Bo; Wang, Huiying; Wu, Kaifeng; Yang, Shengyong; Wang, Yan; Ding, Guifu

    2017-12-01

    The in situ measurement of TSVs deformation at different temperature is meaningful for learning more about the thermal deformation schemes of 3D TSVs in the microelectronic devices. An efficient and smart hotplate based on sheet resistance is designed for offering more heat, producing a uniform temperature distribution, relieving thermal stress and heat concentration issues, and reducing room space, which was optimized by the finite element method (FEM). The fabricated hotplate is efficient and smart (2.5 cm  ×  2.0 cm  ×  0.5 cm) enough to be located in the limited space during measuring. The thermal infrared imager was employed as the temperature sensor for monitoring the temperature distribution of TSVs sample. The 3D profilometry was adopted as the observer for TSVs profiles survey. The in situ 2D top surface profiles and 3D displacement profiles of TSVs sample at the different temperature were measured by 3D profilometer. The in situ average relative deformation and effective plastic deformation of the TSV sample were measured. With optical measurement method, 3D profilometry, the TSV sample can be tested repeatedly.

  13. Thermal design studies in superconducting rf cavities: Phonon peak and Kapitza conductance

    Directory of Open Access Journals (Sweden)

    A. Aizaz

    2010-09-01

    Full Text Available Thermal design studies of superconducting radio frequency (SRF cavities involve two thermal parameters, namely the temperature dependent thermal conductivity of Nb at low temperatures and the heat transfer coefficient at the Nb-He II interface, commonly known as the Kapitza conductance. During the fabrication process of the SRF cavities, Nb sheet is plastically deformed through a deep drawing process to obtain the desired shape. The effect of plastic deformation on low temperature thermal conductivity as well as Kapitza conductance has been studied experimentally. Strain induced during the plastic deformation process reduces the thermal conductivity in its phonon transmission regime (disappearance of phonon peak by 80%, which may explain the performance limitations of the defect-free SRF cavities during their high field operations. Low temperature annealing of the deformed Nb sample could not recover the phonon peak. However, moderate temperature annealing during the titanification process recovered the phonon peak in the thermal conductivity curve. Kapitza conductance measurements for the Nb-He II interface for various surface topologies have also been carried out before and after the annealing. These measurements reveal consistently increased Kapitza conductance after the annealing process was carried out in the two temperature regimes.

  14. High temperature deformation behavior, thermal stability and irradiation performance in Grade 92 steel

    Science.gov (United States)

    Alsagabi, Sultan

    The 9Cr-2W ferritic-martensitic steel (i.e. Grade 92 steel) possesses excellent mechanical and thermophysical properties; therefore, it has been considered to suit more challenging applications where high temperature strength and creep-rupture properties are required. The high temperature deformation mechanism was investigated through a set of tensile testing at elevated temperatures. Hence, the threshold stress concept was applied to elucidate the operating high temperature deformation mechanism. It was identified as the high temperature climb of edge dislocations due to the particle-dislocation interactions and the appropriate constitutive equation was developed. In addition, the microstructural evolution at room and elevated temperatures was investigated. For instance, the microstructural evolution under loading was more pronounced and carbide precipitation showed more coarsening tendency. The growth of these carbide precipitates, by removing W and Mo from matrix, significantly deteriorates the solid solution strengthening. The MX type carbonitrides exhibited better coarsening resistance. To better understand the thermal microstructural stability, long tempering schedules up to 1000 hours was conducted at 560, 660 and 760°C after normalizing the steel. Still, the coarsening rate of M23C 6 carbides was higher than the MX-type particles. Moreover, the Laves phase particles were detected after tempering the steel for long periods before they dissolve back into the matrix at high temperature (i.e. 720°C). The influence of the tempering temperature and time was studied for Grade 92 steel via Hollomon-Jaffe parameter. Finally, the irradiation performance of Grade 92 steel was evaluated to examine the feasibility of its eventual reactor use. To that end, Grade 92 steel was irradiated with iron (Fe2+) ions to 10, 50 and 100 dpa at 30 and 500°C. Overall, the irradiated samples showed some irradiation-induced hardening which was more noticeable at 30°C. Additionally

  15. Investigation of surface deformations by double exposure holographic interferometry

    International Nuclear Information System (INIS)

    Ecevit, F.N.; Guven, H.; Aydin, R.

    1990-01-01

    Surface deformations of rigid bodies produced by thermal as well as mechanical strains have been investigated using double-exposure holographic interferometry. The recorded interference fringes have been discussed qualitatively. (author). 9 refs, 4 figs

  16. Thermally-Induced Structural Disturbances of Rigid Panel Solar Arrays

    Science.gov (United States)

    Johnston, John D.; Thornton, Earl A.

    1997-01-01

    The performance of a significant number of spacecraft has been impacted negatively by attitude disturbances resulting from thermally-induced motions of flexible structures. Recent examples of spacecraft affected by these disturbances include the Hubble Space Telescope (HST) and the Upper Atmosphere Research Satellite (UARS). Thermally-induced structural disturbances occur as the result of rapid changes in thermal loading typically initiated as a satellite exits or enters the Earth's shadow. Temperature differences in flexible appendages give rise to structural deformations, which in turn result in disturbance torques reacting back on the spacecraft. Structures which have proven susceptible to these disturbances include deployable booms and solar arrays. This paper investigates disturbances resulting from thermally-induced deformations of rigid panel solar arrays. An analytical model for the thermal-structural response of the solar array and the corresponding disturbance torque are presented. The effect of these disturbances on the attitude dynamics of a simple spacecraft is then investigated using a coupled system of governing equations which includes the effects of thermally-induced deformations. Numerical results demonstrate the effect of varying solar array geometry on the dynamic response of the system.

  17. Effect of fin attachment on thermal stress reduction of exhaust manifold of an off road diesel engine

    Institute of Scientific and Technical Information of China (English)

    Ali; Akbar; Partoaa; Morteza; Abdolzadeh; Masoud; Rezaeizadeh

    2017-01-01

    The effect of fin attachment on the thermal stress reduction of exhaust manifold of an off road diesel engine(Komatsu HD325-6) was investigated.For doing this,coupled thermo-fluid-solid analysis of exhaust manifold of the off road diesel engine was carried out.The thermal analysis,including thermal flow,thermal stress,and the thermal deformation of the manifold was investigated.The flow inside the manifold was simulated and then its properties including velocity,pressure,and temperature were obtained.The flow properties were transferred to the solid model and then the thermal stresses and the thermal deformations of the manifold under different operating conditions were calculated.Finally,based on the predicted thermal stresses and thermal deformations of the manifold body shell,two fin types as well as body shell thickness increase were applied in the critical induced thermal stress area of the manifold to reduce the thermal stress and thermal deformation.The results of the above modifications show that the combined modifications,i.e.the thickness increase and the fin attachment,decrease the thermal stresses by up to 28% and the contribution of the fin attachment in this reduction is much higher compared to the shell thickness increase.

  18. Structurally Deformed MoS2 for Electrochemically Stable, Thermally Resistant, and Highly Efficient Hydrogen Evolution Reaction

    KAUST Repository

    Chen, Yen-Chang; Lu, Ang-Yu; Lu, Ping; Yang, Xiulin; Jiang, Chang-Ming; Mariano, Marina; Kaehr, Brian; Lin, Oliver; Taylor, André ; Sharp, Ian D.; Li, Lain-Jong; Chou, Stanley S.; Tung, Vincent

    2017-01-01

    The emerging molybdenum disulfide (MoS2) offers intriguing possibilities for realizing a transformative new catalyst for driving the hydrogen evolution reaction (HER). However, the trade-off between catalytic activity and long-term stability represents a formidable challenge and has not been extensively addressed. This study reports that metastable and temperature-sensitive chemically exfoliated MoS2 (ce-MoS2) can be made into electrochemically stable (5000 cycles), and thermally robust (300 °C) while maintaining synthetic scalability and excellent catalytic activity through physical-transformation into 3D structurally deformed nanostructures. The dimensional transition enabled by a high throughput electrohydrodynamic process provides highly accessible, and electrochemically active surface area and facilitates efficient transport across various interfaces. Meanwhile, the hierarchically strained morphology is found to improve electronic coupling between active sites and current collecting substrates without the need for selective engineering the electronically heterogeneous interfaces. Specifically, the synergistic combination of high strain load stemmed from capillarity-induced-self-crumpling and sulfur (S) vacancies intrinsic to chemical exfoliation enables simultaneous modulation of active site density and intrinsic HER activity regardless of continuous operation or elevated temperature. These results provide new insights into how catalytic activity, electrochemical-, and thermal stability can be concurrently enhanced through the physical transformation that is reminiscent of nature, in which properties of biological materials emerge from evolved dimensional transitions.

  19. Structurally Deformed MoS2 for Electrochemically Stable, Thermally Resistant, and Highly Efficient Hydrogen Evolution Reaction

    KAUST Repository

    Chen, Yen-Chang

    2017-10-12

    The emerging molybdenum disulfide (MoS2) offers intriguing possibilities for realizing a transformative new catalyst for driving the hydrogen evolution reaction (HER). However, the trade-off between catalytic activity and long-term stability represents a formidable challenge and has not been extensively addressed. This study reports that metastable and temperature-sensitive chemically exfoliated MoS2 (ce-MoS2) can be made into electrochemically stable (5000 cycles), and thermally robust (300 °C) while maintaining synthetic scalability and excellent catalytic activity through physical-transformation into 3D structurally deformed nanostructures. The dimensional transition enabled by a high throughput electrohydrodynamic process provides highly accessible, and electrochemically active surface area and facilitates efficient transport across various interfaces. Meanwhile, the hierarchically strained morphology is found to improve electronic coupling between active sites and current collecting substrates without the need for selective engineering the electronically heterogeneous interfaces. Specifically, the synergistic combination of high strain load stemmed from capillarity-induced-self-crumpling and sulfur (S) vacancies intrinsic to chemical exfoliation enables simultaneous modulation of active site density and intrinsic HER activity regardless of continuous operation or elevated temperature. These results provide new insights into how catalytic activity, electrochemical-, and thermal stability can be concurrently enhanced through the physical transformation that is reminiscent of nature, in which properties of biological materials emerge from evolved dimensional transitions.

  20. Strain measurement of objects subjected to aerodynamic heating using digital image correlation: experimental design and preliminary results.

    Science.gov (United States)

    Pan, Bing; Jiang, Tianyun; Wu, Dafang

    2014-11-01

    In thermomechanical testing of hypersonic materials and structures, direct observation and quantitative strain measurement of the front surface of a test specimen directly exposed to severe aerodynamic heating has been considered as a very challenging task. In this work, a novel quartz infrared heating device with an observation window is designed to reproduce the transient thermal environment experienced by hypersonic vehicles. The specially designed experimental system allows the capture of test article's surface images at various temperatures using an optical system outfitted with a bandpass filter. The captured images are post-processed by digital image correlation to extract full-field thermal deformation. To verify the viability and accuracy of the established system, thermal strains of a chromiumnickel austenite stainless steel sample heated from room temperature up to 600 °C were determined. The preliminary results indicate that the air disturbance between the camera and the specimen due to heat haze induces apparent distortions in the recorded images and large errors in the measured strains, but the average values of the measured strains are accurate enough. Limitations and further improvements of the proposed technique are discussed.

  1. A Deformation Model of TRU Metal Dispersion Fuel Rod for HYPER

    International Nuclear Information System (INIS)

    Lee, Byoung Oon; Hwang, Woan; Park, Won S.

    2002-01-01

    Deformation analysis in fuel rod design is essential to assure adequate fuel performance and integrity under irradiation conditions. An in-reactor performance computer code for a dispersion fuel rod is being developed in the conceptual design stage of blanket fuel for HYPER. In this paper, a mechanistic deformation model was developed and the model was installed into the DIMAC program. The model was based on the elasto-plasticity theory and power-law creep theory. The preliminary deformation calculation results for (TRU-Zr)-Zr dispersion fuel predicted by DIMAC were compared with those of silicide dispersion fuel predicted by DIFAIR. It appeared that the deformation levels for (TRU-Zr)-Zr dispersion fuel were relatively higher than those of silicide fuel. Some experimental tests including in-pile and out-pile experiments are needed for verifying the predictive capability of the DIMAC code. An in-reactor performance analysis computer code for blanket fuel is being developed at the conceptual design stage of blanket fuel for HYPER. In this paper, a mechanistic deformation model was developed and the model was installed into the DIMAC program. The model was based on the elasto-plasticity theory and power-law creep theory. The preliminary deformation calculation results for (TRUZr)- Zr dispersion fuel predicted by DIMAC were compared with those of silicide dispersion fuel predicted by DIFAIR. It appears that the deformation by swelling within fuel meat is very large for both fuels, and the major deformation mechanism at cladding is creep. The swelling strain is almost constant within the fuel meat, and is assumed to be zero in the cladding made of HT9. It is estimated that the deformation levels for (TRU-Zr)-Zr dispersion fuel were relatively higher than those of silicide fuel, and the dispersion fuel performance may be limited by swelling. But the predicted volume change of the (TRU-Zr)-Zr dispersion fuel models is about 6.1% at 30 at.% burnup. The value of cladding

  2. Ground Deformation Detection Using China’s ZY-3 Stereo Imagery in an Opencast Mining Area

    OpenAIRE

    Wenmin Hu; Lixin Wu; Wei Zhang; Bin Liu; Jiaxing Xu

    2017-01-01

    Detection and extraction of mining-induced ground deformation can be used to understand the deformation process and space distribution and to estimate the deformation laws and trends. This study focuses on the application of ground deformation detection and extraction combined with digital surface model (DSM), derived from China’s ZiYuan-3 (ZY-3) satellite stereo imagery and the advanced spaceborne thermal emission and reflection radiometer global digital elevation model (ASTER GDEM) data. A ...

  3. In-situ neutron diffraction characterization of temperature dependence deformation in α-uranium

    Science.gov (United States)

    Calhoun, C. A.; Garlea, E.; Sisneros, T. A.; Agnew, S. R.

    2018-04-01

    In-situ strain neutron diffraction measurements were conducted at temperature on specimens coming from a clock-rolled α-uranium plate, and Elasto-Plastic Self-Consistent (EPSC) modeling was employed to interpret the findings. The modeling revealed that the active slip systems exhibit a thermally activated response, while deformation twinning remains athermal over the temperature ranges explored (25-150 °C). The modeling also allowed assessment of the effects of thermal residual stresses on the mechanical response during compression. These results are consistent with those from a prior study of room-temperature deformation, indicating that the thermal residual stresses strongly influence the internal strain evolution of grain families, as monitored with neutron diffraction, even though accounting for these residual stresses has little effect on the macroscopic flow curve, except in the elasto-plastic transition.

  4. A two-step approach for the preliminary evaluation of the thermal-hydraulics and safety of the ELSY open square core design

    International Nuclear Information System (INIS)

    Meloni, Paride; Bandini, Giacomino; Polidori, Massimiliano; Cervone, Antonio; Manservisi, Sandro

    2009-01-01

    Several innovative solutions for a liquid metal fast reactor design have been investigated in the EURATOM Sixth Framework Programme and an open-assembly core design for the ELSY (European Lead-cooled System) reactor has been proposed by ENEA. The development of this new reactor, based on innovative neutronic and safety considerations, requires a new approach to the thermal-hydraulic (T/H) core design. In this paper a new two-step approach of the T/H analysis for this open-assembly core is presented and, in particular is used for the evaluation of the preliminary core design of a 1500 MW lead fast reactor with open square lattice and three fuel radial zones with different levels of enrichment. In the first step a preliminary thermal-hydraulic and safety evaluation of the core neutronic design is investigated by using a one-dimensional RELAP5 model for independent channel analysis. Then two and three-dimensional effects are taken into account by using a dedicated tool for the evaluation of assembly mixing effects. The RELAP5 model, based on pressure loss and heat transfer correlations available for heavy liquid metal flows in rod bundle, consists of completely independent assemblies and therefore it can be used for a conservative evaluation of the thermal-hydraulics of the core reactor. Due to the open-lattice configuration, the two and three-dimensional effects are important and they are taken into account by using a simplified three-dimensional numerical model of an open square lattice reactor core, developed with the purpose of analyzing the whole core behavior. The numerical simulation is performed at assembly length level taking into account the local fluctuations of turbulent viscosity and energy exchange coefficients at sub-channel level through transfer operators based on parametric coefficients. A preliminary evaluation of the mixing effects between assembly flows on the temperature field has been performed by using an average assembly turbulent viscosity

  5. Microstructure and mechanical properties of precipitation hardened aluminum under high rate deformation

    International Nuclear Information System (INIS)

    Grady, D.E.; Asav, J.R.; Rohde, R.W.; Wise, J.L.

    1983-01-01

    This chapter attempts to correlate the shock compression and quasistatic deformation of 6061-T6 aluminium. Examines recovered specimens which have been shock loaded, and compares results with both static and dynamic mechanical property measurements. Discusses experimental procedures (reshock and unloading experiments, shock recovery techniques, metallographic techniques and coldwork experiments); dynamic strength and wave-profile properties (strength and shear-stress states on the Hugoniot, steady-wave risetime and viscosity); quasistatic and shock metallography studies (metallography of quasistatically deformed material; metallography of shock deformed specimens; comparison of static and shock deformation; correlation of hardness and dynamic strength measurements); and thermal trapping calculations in shocked aluminium (heterogeneous deformation and adiabatic heating in shock-wave loading; energy and risetime relations under steadywave shock compression; heterogeneous temperature calculations in aluminium). Concludes that heterogeneous shear deformation appears to play a role in the dynamic deformation process

  6. Equivalent Energy Density concept: A preliminary reexamination of a technique for equating thermal loads

    International Nuclear Information System (INIS)

    Ryder, E.E.

    1992-08-01

    Historical and projected inventories of spent fuel from commercial light-water nuclear reactors exhibit diverse decay characteristics and ages. This report summarizes a preliminary reexamination of a method for determining equivalent thermal loads for the range of spent fuel expected at a potential underground repository. The method, known at the Equivalent Energy Density (EED) concept, bases its equivalence criteria on the assumption that a given waste will produce worst-case thermomechanical effects equal to worst-case thermomechanical effects produced by a baseline waste, provided that the thermal energy deposited in the host rock over a specified deposition period is the same for both waste descriptions. To test this assumption, temperature histories at representative locations within the host rock were calculated using layouts defined by the EED concept and four deposition periods (20, 50, 100, and 300 years). It was found that the peak temperatures at near-field locations were best matched by the shorter deposition periods of 20 and 50 years. However, due to the sensitivity of the near-field environment to short-term canister-to-canister interactions, caution,should be used when choosing a near-field deposition period. At the location chosen to represent the far-field, a 300-year deposition period provided reasonable correspondence of peak temperature responses for all waste descriptions examined

  7. Preliminary applications of the new Neptune two-phase CFD solver to pressurized thermal shock investigations

    International Nuclear Information System (INIS)

    Boucker, M.; Laviaville, J.; Martin, A.; Bechaud, C.; Bestion, D.; Coste, P.

    2004-01-01

    The objective of this communication is to present some preliminary applications to pressurized thermal shock (PTS) investigations of the CFD (Computational Fluid Dynamics) two-phase flow solver of the new NEPTUNE thermal-hydraulics platform. In the framework of plant life extension, the Reactor Pressure Vessel (RPV) integrity is a major concern, and an important part of RPV integrity assessment is related to PTS analysis. In the case where the cold legs are partially filled with steam, it becomes a two-phase problem and new important effects occur, such as condensation due to the Emergency Core Cooling (ECC) injections of sub-cooled water. Thus, an advanced prediction of RPV thermal loading during these transients requires sophisticated two-phase, local scale, 3-dimensional codes. In that purpose, a program has been set up to extend the capabilities of the NEPTUNE two-phase CFD solver. A simple set of turbulence and condensation model for free surface steam-water flow has been tested in simulation of an ECC high pressure injection representing facility, using a full 3-dimensional mesh and the new NEPTUNE solver. Encouraging results have been obtained but it should be noticed that several sources of error can compensate for one another. Nevertheless, the computation presented here allows to be reasonable confident in the use of two-phase CFD in order to carry out refined analysis of two-phase PTS scenarios within the next years

  8. Optical Coherence Tomography for Tracking Canvas Deformation

    International Nuclear Information System (INIS)

    Targowski, P.; Gora, M.; Bajraszewski, T.; Szkulmowski, M.; Rouba, B.; Lekawa-Wyslouch, T.; Tyminska-Widmer, L.

    2006-01-01

    Preliminary results of the application of optical coherence tomography (OCT), in particular in its spectral mode (SOCT), to tracking of deformations in paintings on canvas caused by periodical humidity changes are presented. The setup is able to monitor the position of a chosen point at the surface of a painting with micrometre precision, simultaneously in three dimensions, every 100 seconds. This allows recording of deformations associated with crack formation. For the particular painting model examined, it was shown that the surface moves in-plane towards the corner, and bulges outwards (Z-direction) in response to a rise in humidity. Subsequent to the first humidification/drying cycle, translation in the Z-direction is decreased, whilst in-plane translations increase somewhat. It was also shown that the response of the painting on canvas begins immediately on changing the relative humidity in the surroundings.

  9. Non-invasive imaging of zebrafish with spinal deformities using optical coherence tomography: a preliminary study

    Science.gov (United States)

    Bernstein, Liane; Beaudette, Kathy; Patten, Kessen; Beaulieu-Ouellet, Émilie; Strupler, Mathias; Moldovan, Florina; Boudoux, Caroline

    2013-03-01

    A zebrafish model has recently been introduced to study various genetic mutations that could lead to spinal deformities such as scoliosis. However, current imaging techniques make it difficult to perform longitudinal studies of this condition in zebrafish, especially in the early stages of development. The goal of this project is to determine whether optical coherence tomography (OCT) is a viable non-invasive method to image zebrafish exhibiting spinal deformities. Images of both live and fixed malformed zebrafish (5 to 21 days postfertilization) as well as wild-type fish (5 to 29 days postfertilization) were acquired non-invasively using a commercial SD-OCT system, with a laser source centered at 930nm (λ=100nm), permitting axial and lateral resolutions of 7 and 8μm respectively. Using two-dimensional images and three-dimensional reconstructions, it was possible to identify the malformed notochord as well as deformities in other major organs at different stages of formation. Visualization of the notochord was facilitated with the development of a segmentation algorithm. OCT images were compared to HE histological sections and images obtained by calcein staining. Because of the possibility of performing longitudinal studies on a same fish and reducing image processing time as compared with staining techniques and histology, the use of OCT could facilitate phenotypic characterization in studying genetic factors leading to spinal deformities in zebrafish and could eventually contribute to the identification of the genetic causes of spinal deformities such as scoliosis.

  10. Study of regularities in propagation of thermal fatigue cracks

    International Nuclear Information System (INIS)

    Tachkova, N.G.; Sobolev, N.D.; Egorov, V.I.; Rostovtsev, Yu.V.; Ivanov, Yu.S.; Sirotin, V.L.

    1978-01-01

    Regularities in the propagation of thermal fatigue cracks in the Cr-Ni steels of the austenite class depending upon deformation conditions in the crack zone, have been considered. Thin-walled tube samples of the Kh16N40, Kh18N20 and Kh16N15 steels have been tested in the 10O reversible 400 deg C and 100 reversible 500 deg C regimes. The samples have possessed a slot-shaped stress concentrator. Stress intensity pseudocoefficient has been calculated for the correlation of experimental data. The formula for determining crack propagation rate has been obtained. The experiments permit to conclude that propagation rate of thermal fatigue cracks in the above steels depends upon the scope of plastic deformation during a cycle and stress intensity pseudocoefficient, and is determined by plastic deformation resistance during thermal cyclic loading

  11. Thermal Analysis of Iodine Satellite (iSAT) from Preliminary Design Review (PDR) to Critical Design Review (CDR)

    Science.gov (United States)

    Mauro, Stephanie

    2016-01-01

    The Iodine Satellite (iSAT) is a 12U cubesat with a primary mission to demonstrate the iodine fueled Hall Effect Thruster (HET) propulsion system. The spacecraft (SC) will operate throughout a one year mission in an effort to mature the propulsion system for use in future applications. The benefit of the HET is that it uses a propellant, iodine, which is easy to store and provides a high thrust-to-mass ratio. This paper will describe the thermal analysis and design of the SC between Preliminary Design Review (PDR) and Critical Design Review (CDR). The design of the satellite has undergone many changes due to a variety of challenges, both before PDR and during the time period discussed in this paper. Thermal challenges associated with the system include a high power density, small amounts of available radiative surface area, localized temperature requirements of the propulsion components, and unknown orbital parameters. The thermal control system is implemented to maintain component temperatures within their respective operational limits throughout the mission, while also maintaining propulsion components at the high temperatures needed to allow gaseous iodine propellant to flow. The design includes heaters, insulation, radiators, coatings, and thermal straps. Currently, the maximum temperatures for several components are near to their maximum operation limit, and the battery is close to its minimum operation limit. Mitigation strategies and planned work to solve these challenges will be discussed.

  12. Ductility and resistance to deformation of EhP975 alloy during hot plastic working

    International Nuclear Information System (INIS)

    Baturin, A.I.; Martynov, A.I.

    1982-01-01

    Results of investigations into ductility and resistance to deformation of the EhP975 most heat-resistant difficult-to-form alloy of commercial melting in 1000-1200 deg C temperature range and at deformation rates epsilon = 0.1 - 25 s - 1 are presented. It is shown that ductility of EhP975 alloy grows rather slowly with increase of temperature approximately up to 1075 deg C, then sharp growth of ductility up to the maximum at 1120-1125 deg C is observed; ductility decreases above this temperature zone. It was also established that ductility of EhP975 alloy grows with increase of preliminary deformation degree. It is marked that high temperature annealing increases ductility of EhP975 alloy in comparison with (cast state), especially noticeably at high deformation rates

  13. Thermal stress relaxation in magnesium composites during thermal cycling

    Energy Technology Data Exchange (ETDEWEB)

    Trojanova, Z.; Lukac, P. (Karlova Univ., Prague (Czech Republic)); Kiehn, J.; Kainer, K.U.; Mordike, B.L. (Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany))

    1998-01-01

    It has been shown that the internal friction of Mg - Saffil metal matrix composites can be influenced by thermal stresses, if MMCc are submitted to thermal cycling between room temperature and an upper temperature of cycling. These stresses can be accommodated by generation and motion of dislocations giving the formation of the microplastic zones. The thermal stress relaxation depends on the upper temperature of cycling, the volume fraction of reinforcement and the matrix composition and can result in plastic deformation and strain hardening of the matrix without applied stress. The internal friction measurements can be used for non destructive investigation of processes which influence the mechanical properties. (orig.)

  14. Intermediate size inducer pump - structural analysis and transient deformation studies

    International Nuclear Information System (INIS)

    Cheng, T.K.; Nishizaka, J.N.

    1979-05-01

    This report summarizes the structural and thermal transient deformation analysis of the Intermediate Size Inducer Pump. The analyses were performed in accordance to the requirements of N266ST310001, the specification for the ISIP. Results of stress analysis indicate that the thermal transient stress and strain are within the stress strain limits of RDT standard F9-4 which was used as a guide

  15. Ocean thermal energy conversion power system development-I. Phase I. Preliminary design report. Volume 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-18

    The results of a conceptual and preliminary design study of Ocean Thermal Energy Conversion (OTEC) closed loop ammonia power system modules performed by Lockheed Missiles and Space Company, Inc. (LMSC) are presented. This design study is the second of 3 tasks in Phase I of the Power System Development-I Project. The Task 2 objectives were to develop: 1) conceptual designs for a 40 to 50-MW(e) closed cycle ammonia commercial plant size power module whose heat exchangers are immersed in seawater and whose ancillary equipments are in a shirt sleeve environment; preliminary designs for a modular application power system sized at 10-MW(e) whose design, construction and material selection is analogous to the 50 MW(e) module, except that titanium tubes are to be used in the heat exchangers; and 3) preliminary designs for heat exchanger test articles (evaporator and condenser) representative of the 50-MW(e) heat exchangers using aluminum alloy, suitable for seawater service, for testing on OTEC-1. The reference ocean platform was specified by DOE as a surface vessel with the heat exchanger immersed in seawater to a design depth of 0 to 20 ft measured from the top of the heat exchanger. For the 50-MW(e) module, the OTEC 400-MW(e) Plant Ship, defined in the Platform Configuration and Integration study, was used as the reference platform. System design, performance, and cost are presented. (WHK)

  16. Gate-tunable gigantic lattice deformation in VO2

    International Nuclear Information System (INIS)

    Okuyama, D.; Hatano, T.; Nakano, M.; Takeshita, S.; Ohsumi, H.; Tardif, S.; Shibuya, K.; Yumoto, H.; Koyama, T.; Ohashi, H.; Takata, M.; Kawasaki, M.; Tokura, Y.; Iwasa, Y.; Arima, T.

    2014-01-01

    We examined the impact of electric field on crystal lattice of vanadium dioxide (VO 2 ) in a field-effect transistor geometry by in-situ synchrotron x-ray diffraction measurements. Whereas the c-axis lattice parameter of VO 2 decreases through the thermally induced insulator-to-metal phase transition, the gate-induced metallization was found to result in a significant increase of the c-axis length by almost 1% from that of the thermally stabilized insulating state. We also found that this gate-induced gigantic lattice deformation occurs even at the thermally stabilized metallic state, enabling dynamic control of c-axis lattice parameter by more than 1% at room temperature

  17. Dynamic Deformation of ETNA Volcano Observed by GPS and SAR Interferometry

    Science.gov (United States)

    Lundgren, P.; Rosen, P.; Webb, F.; Tesauro, M.; Lanari, R.; Sansosi, E.; Puglisi, G.; Bonforte, A.; Coltelli, M.

    1999-01-01

    Synthetic aperture radar (SAR) interferometry and GPS have shown that during the quiescent period from 1993-1995 Mt. Etna volcano, Italy, inflated. Since the initiation of eruptive activity since late 1995 the deformation has been more contentious. We will explore the detailed deformation during the period from 1995-1996 spanning the late stages of inflation and the beginning of eruptive activity. We use SAR interferometry and GPS data to measure the volcano deformation. We invert the observed deformation for both simple point source. le crack elastic sources or if warranted for a spheroidal pressure So In particular, we will examine the evolution of the inflation and the transition to a lesser deflation observed at the end of 1995. We use ERS-1/2 SAR data from both ascending and descending passes to allow for dense temporal 'sampling of the deformation and to allow us to critically assess atmospheric noise. Preliminary results from interferometry suggest that the inflation rate accelerated prior to resumption of activity in 1995, while GPS data suggest a more steady inflation with some fluctuation following the start of activity. This study will compare and contrast the interferometric SAR and GPS results and will address the strengths and weaknesses of each technique towards volcano deformation studies.

  18. Thermal image analysis of plastic deformation and fracture behavior by a thermo-video measurement system

    International Nuclear Information System (INIS)

    Ohbuchi, Yoshifumi; Sakamoto, Hidetoshi; Nagatomo, Nobuaki

    2016-01-01

    The visualization of the plastic region and the measurement of its size are necessary and indispensable to evaluate the deformation and fracture behavior of a material. In order to evaluate the plastic deformation and fracture behavior in a structural member with some flaws, the authors paid attention to the surface temperature which is generated by plastic strain energy. The visualization of the plastic deformation was developed by analyzing the relationship between the extension of the plastic deformation range and the surface temperature distribution, which was obtained by an infrared thermo-video system. Furthermore, FEM elasto-plastic analysis was carried out with the experiment, and the effectiveness of this non-contact measurement system of the plastic deformation and fracture process by a thermography system was discussed. The evaluation method using an infrared imaging device proposed in this research has a feature which does not exist in the current evaluation method, i.e. the heat distribution on the surface of the material has been measured widely by noncontact at 2D at high speed. The new measuring technique proposed here can measure the macroscopic plastic deformation distribution on the material surface widely and precisely as a 2D image, and at high speed, by calculation from the heat generation and the heat propagation distribution. (paper)

  19. Inverted temperature sequences: role of deformation partitioning

    Science.gov (United States)

    Grujic, D.; Ashley, K. T.; Coble, M. A.; Coutand, I.; Kellett, D.; Whynot, N.

    2015-12-01

    The inverted metamorphism associated with the Main Central thrust zone in the Himalaya has been historically attributed to a number of tectonic processes. Here we show that there is actually a composite peak and deformation temperature sequence that formed in succession via different tectonic processes. The deformation partitioning seems to the have played a key role, and the magnitude of each process has varied along strike of the orogen. To explain the formation of the inverted metamorphic sequence across the Lesser Himalayan Sequence (LHS) in eastern Bhutan, we used Raman spectroscopy of carbonaceous material (RSCM) to determine the peak metamorphic temperatures and Ti-in-quartz thermobarometry to determine the deformation temperatures combined with thermochronology including published apatite and zircon U-Th/He and fission-track data and new 40Ar/39Ar dating of muscovite. The dataset was inverted using 3D-thermal-kinematic modeling to constrain the ranges of geological parameters such as fault geometry and slip rates, location and rates of localized basal accretion, and thermal properties of the crust. RSCM results indicate that there are two peak temperature sequences separated by a major thrust within the LHS. The internal temperature sequence shows an inverted peak temperature gradient of 12 °C/km; in the external (southern) sequence, the peak temperatures are constant across the structural sequence. Thermo-kinematic modeling suggest that the thermochronologic and thermobarometric data are compatible with a two-stage scenario: an Early-Middle Miocene phase of fast overthrusting of a hot hanging wall over a downgoing footwall and inversion of the synkinematic isotherms, followed by the formation of the external duplex developed by dominant underthrusting and basal accretion. To reconcile our observations with the experimental data, we suggest that pervasive ductile deformation within the upper LHS and along the Main Central thrust zone at its top stopped at

  20. Thermal Excitation System for Shearography (TESS)

    Science.gov (United States)

    Lansing, Matthew D.; Bullock, Michael W.

    1996-01-01

    One of the most convenient and effective methods of stressing a part or structure for shearographic evaluation is thermal excitation. This technique involves heating the part, often convectively with a heat gun, and then monitoring with a shearography device the deformation during cooling. For a composite specimen, unbonds, delaminations, inclusions, or matrix cracking will deform during cooling differently than other more structurally sound regions and thus will appear as anomalies in the deformation field. However, one of the difficulties that cause this inspection to be dependent on the operator experience is the conventional heating process. Fanning the part with a heat gun by hand introduces a wide range of variability from person to person and from one inspection to the next. The goal of this research effort was to conduct research in the methods of thermal excitation for shearography inspection. A computerized heating system was developed for inspection of 0.61 m (24 in.) square panels. The Thermal Excitation System for Shearography (TESS) provides radiant heating with continuous digital measurement of the surface temperature profile to ensure repeatability. The TESS device functions as an accessory to any electronic shearography device.

  1. Effect of cyclic block loading on character of deformation and strength of structural materials in plane stressed state

    International Nuclear Information System (INIS)

    Kul'chitskij, N.M.; Troshchenko, A.V.; Koval'chuk, B.I.; Khamaza, L.A.; Nikolaev, I.A.

    1982-01-01

    The paper is concerned with choice of conditions for preliminary cyclic block loading, determination of fatigue failure resistance characteristics for various structural materials under regular and selected block loading, investigation of the preliminary cyclic loading effect on regularities of elastoplastic deformation of materials concerned in the biaxial stressed state. Under selected conditions of cyclic block loading the character of damage accumulation is close to the linear law for the materials of high-srength doped steel, and VT6 alloys of concern. These materials in the initial state and after preliminary cyclic loading are anisotropic. Axial direction is characterized by a higher plastic strain resistance for steel and tangential direction - for VT6 alloy. The generalized strain curves for the materials in question are not invariant as to the stressed state type. It is stated that the effect of preliminary unsteady cyclic loading on resistance and general regularities of material deformation in the complex stressed state is insignificant. It is observed that stress-strain properties of the materials tend to vary in the following way: plastic strain resistance of the steel lowers and that of VT6 rises, anisotropy of the materials somehow decreases. The variation in the material anisotropy may be attributed to a decrease in residual stresses resulting from preliminary cyclic loading

  2. Application of electronic speckle-pattern interferometry to measure in-plane thermal displacement in flip-chip packages

    International Nuclear Information System (INIS)

    Lee, Baik-Woo; Jang, Woosoon; Kim, Dong-Won; Jeong, Jeung-hyun; Nah, Jae-Woong; Paik, Kyung-Wook; Kwon, Dongil

    2004-01-01

    Electronic speckle-pattern interferometry (ESPI) was applied for noncontact, real-time evaluation of thermal deformation in a flip-chip package. The spatial resolution of ESPI was increased to submicron scale by magnifying the areas studied in order to measure the deformation of such small-scale components as the solder in the flip-chip package. Thermal deformation in the horizontal and vertical directions around the solder joints was measured as two-dimensional mappings during heating from 25 to 125 deg. C. ESPI was successful in obtaining information on the complicated deformation field around the solder joints. Furthermore, the shear strain could also be calculated using the measured thermal deformation around each solder joint. The applicability of ESPI to flip-chip packages was verified by comparing the ESPI results with those of finite-element analysis (FEA)

  3. VLT deformable secondary mirror: integration and electromechanical tests results

    Science.gov (United States)

    Biasi, R.; Andrighettoni, M.; Angerer, G.; Mair, C.; Pescoller, D.; Lazzarini, P.; Anaclerio, E.; Mantegazza, M.; Gallieni, D.; Vernet, E.; Arsenault, R.; Madec, P.-Y.; Duhoux, P.; Riccardi, A.; Xompero, M.; Briguglio, R.; Manetti, M.; Morandini, M.

    2012-07-01

    The VLT Deformable secondary is planned to be installed on the VLT UT#4 as part of the telescope conversion into the Adaptive Optics test Facility (AOF). The adaptive unit is based on the well proven contactless, voice coil motor technology that has been already successfully implemented in the MMT, LBT and Magellan adaptive secondaries, and is considered a promising technical choice for the forthcoming ELT-generation adaptive correctors, like the E-ELT M4 and the GMT ASM. The VLT adaptive unit has been recently assembled after the completion of the manufacturing and modular test phases. In this paper, we present the most relevant aspects of the system integration and report the preliminary results of the electromechanical tests performed on the unit. This test campaign is a typical major step foreseen in all similar systems built so far: thanks to the metrology embedded in the system, that allows generating time-dependent stimuli and recording in real time the position of the controlled mirror on all actuators, typical dynamic response quality parameters like modal settling time, overshoot and following error can be acquired without employing optical measurements. In this way the system dynamic and some aspect of its thermal and long term stability can be fully characterized before starting the optical tests and calibrations.

  4. Campaigned GPS on Present-Day Crustal Deformation in Northernmost Longitudinal Valley Preliminary Results, Hualien Taiwan

    Directory of Open Access Journals (Sweden)

    Chia-Yu Chen

    2014-01-01

    Full Text Available The Longitudinal Valley in Eastern Taiwan sits at the collision suture between the Eurasian and Philippine Sea plates. Based on repeated GPS campaigned measurements from 25 stations six times in 2007 - 2009, we characterize the surface deformation in the northernmost Longitudinal Valley where the Coastal Range of the Philippine Sea plate turns northward diving under the Eurasian plate producing two major active faults: the Milun fault and the Longitudinal Valley fault. We reconstructed a GPS velocity field and conducted strain analyses and elastic block modeling. Our results suggest a rapid clockwise rotation of 33° Myr-1 and an eastward tectonic escape in the small Hualien City block (HUAL area of ~10 × 10 km, which is apparently detached from the regional rotating RYUK block defined by previous studies. We interpret it as being initiated locally by the northwest indentation of the Coastal Range, which pushed the HUAL block to move upward and eastward. According to our strain analyses, the HUAL block shows a significant internal elastic strain inside the Milun Tableland, the hanging wall of the Milun fault. No significant deformation was observed across the surface trace of the fault, indicating that the Milun fault is now probably locked in the near surface. The deformation in the footwall of the fault was accommodated by pure-shear strain with a major NNW-compression and a minor ENE-extension. The deformation in the hanging wall is characterized by simple-shear strain with ENE-extension in its northern part and little deformation in the southern part, separated by a little known NW-trending active fault zone (Dongmingyi fault, which needs further investigation.

  5. Plastic deformation of cubic zirconia single crystals at 1400 C

    International Nuclear Information System (INIS)

    Baufeld, B.; Baither, D.; Bartsch, M.; Messerschmidt, U.

    1998-01-01

    Cubic zirconia single crystals stabilized with 11 mol% yttria were deformed in air at 1400 C and around 1200 C at different strain rates along [1 anti 12] and [100] compression directions. The strain rate sensitivity of the flow stress was determined by strain rate cycling and stress relaxation tests. The microstructure of the deformed specimens was investigated by transmission high-voltage electron microscopy, including contrast extinction analysis for determining the Burgers vectors as well as stereo pairs and wide-angle tilting experiments to find the active slip planes. At deformation along [1 anti 12], the primary and secondary slip planes are of {100} type. Previous experiments had shown that the dislocations move easily on these planes in an athermal way. During deformation along [100], mainly dislocations on {100} planes are activated, which move in a viscous way by the aid of thermal activation. The discussion of the different deformation behaviours during deformation along [1 anti 12] and [100] is based on the different dynamic properties of dislocations and the fact that recovery is an essential feature of the deformation of cubic zirconia at 1400 C. The results on the shape of the deformation curve and the strain rate sensitivity of the flow stress are partly at variance with those of previous authors. (orig.)

  6. Ocean thermal energy conversion (OTEC) power system development. Preliminary design report, Appendices, Part 1 (Final)

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    The objective of this project is the development of a preliminary design for a full-sized, closed cycle, ammonia power system module for the 100 MWe OTEC demonstration plant. In turn, this demonstration plant is to demonstrate, by 1984, the operation and performance of an Ocean Thermal Power Plant having sufficiently advanced heat exchanger design to project economic viability for commercial utilization in the late 1980's and beyond. Included in this power system development are the preliminary designs for a proof-of-concept pilot plant and test article heat exchangers which are scaled in such a manner as to support a logically sequential, relatively low-cost development of the full-scale power system module. The conceptual designs are presented for the demonstration plant power module, the proof-of-concept pilot plant, and for a pair of test article heat exchangers. Costs associated with the design, development, fabrication, checkout, delivery, installation, and operation are included. The accompanying design and producibilty studies on the full-scale power system module project the performance/economics for the commercial plant. This section of the report contains appendices on the developed computer models, water system dynamic studies, miscellaneous performance analysis, materials and processes, detailed equipment lists, turbine design studies, tube cleaner design, ammonia leak detection, and heat exchanger design supporting data. (WHK)

  7. Deformation Modes and Anisotropy of Anti-Perovskite Ti3AN (A = Al, In and Tl from First-Principle Calculations

    Directory of Open Access Journals (Sweden)

    Kuankuan Chen

    2017-03-01

    Full Text Available Deformation modes were studied for Ti3AN (A = Al, In and Tl by applying strain to the materials using first-principle calculations. The states of the bonds changed during the deformation process, and the Ti-N bonds remained structurally stable under deformation. The elastic anisotropy, electronic structures, hardness, and minimum thermal conductivity of anti-perovskite Ti3AN were investigated using the pseudo potential plane-wave method based on density functional theory. We found that the anisotropy of Ti3InN was significantly larger than that of Ti3AlN and Ti3TlN. All three compounds were mechanically stable. The band structures of the three compounds revealed that they were conductors. The minimum thermal conductivities at high temperature in the propagation directions of [100], [110], and [111] were calculated by the acoustic wave velocity, which indicated that the thermal conductivity was also anisotropic. It is indicated that Ti3InN is a good thermal barrier material.

  8. Bayesian networks modeling for thermal error of numerical control machine tools

    Institute of Scientific and Technical Information of China (English)

    Xin-hua YAO; Jian-zhong FU; Zi-chen CHEN

    2008-01-01

    The interaction between the heat source location,its intensity,thermal expansion coefficient,the machine system configuration and the running environment creates complex thermal behavior of a machine tool,and also makes thermal error prediction difficult.To address this issue,a novel prediction method for machine tool thermal error based on Bayesian networks (BNs) was presented.The method described causal relationships of factors inducing thermal deformation by graph theory and estimated the thermal error by Bayesian statistical techniques.Due to the effective combination of domain knowledge and sampled data,the BN method could adapt to the change of running state of machine,and obtain satisfactory prediction accuracy.Ex-periments on spindle thermal deformation were conducted to evaluate the modeling performance.Experimental results indicate that the BN method performs far better than the least squares(LS)analysis in terms of modeling estimation accuracy.

  9. Meso- and microscale vein structures in fore-arc basalts and boninites related to post-magmatic tectonic deformation in the outer Izu-Bonin-Mariana fore arc system: preliminary results from IODP Expedition 352

    Science.gov (United States)

    Quandt, Dennis; Micheuz, Peter; Kurz, Walter

    2016-04-01

    The International Ocean Discovery Program (IODP) Expedition 352 aimed to drill through the entire volcanic sequence of the Izu-Bonin-Mariana fore arc. Two drill sites are situated on the outer fore arc composed of fore arc basalts (FAB) whereas two more sites are located on the upper trench slope penetrating the younger boninites. First results from IODP Expedition 352 and preliminary post-cruise data suggest that FAB were generated by decompression melting during near-trench sea-floor spreading, and that fluids from the subducting slab were not involved in their genesis. Subduction zone fluids involved in boninite genesis appear to have been derived from progressively higher temperatures and pressures over time as the subducting slab thermally matured. Structures within the drill cores combined with borehole and site survey seismic data indicate that tectonic deformation in the outer Izu-Bonin-Mariana fore arc is mainly post-magmatic associated with the development of syn-tectonic sedimentary basins. Within the magmatic basement deformation was accommodated by shear along cataclastic fault zones and the formation of tension fractures, shear fractures and hybrid (tension and shear) fractures. Veins form by mineral filling of tension or hybrid fractures and show no or limited observable macroscale displacement along the fracture plane. (Low Mg-) Calcite and/or various types of zeolite are the major vein constituents, where the latter are considered to be alteration products of basaltic glass. Micrite contents vary significantly and are related to neptunian dikes. In boninites calcite develops mainly blocky shapes but veins with fibrous and stretched crystals also occur in places indicating antitaxial as well as ataxial growth, respectively. In FAB calcite forms consistently blocky crystals without any microscopic identifiable growth direction suggesting precipitation from a highly supersaturated fluid under dropping fluid pressure conditions. However, fluid pressure

  10. Review of prediction for thermal contact resistance

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Theoretical prediction research on thermal contact resistance is reviewed in this paper. In general, modeling or simulating the thermal contact resistance involves several aspects, including the descriptions of surface topography, the analysis of micro mechanical deformation, and the thermal models. Some key problems are proposed for accurately predicting the thermal resistance of two solid contact surfaces. We provide a perspective on further promising research, which would be beneficial to understanding mechanisms and engineering applications of the thermal contact resistance in heat transport phenomena.

  11. Effect of dynamic plastic deformation on microstructure and annealing behaviour of modified 9Cr-1Mo steel

    DEFF Research Database (Denmark)

    Zhang, Zhenbo; Mishin, Oleg V.; Tao, N. R.

    2015-01-01

    after quasi- static compression. The microstructure after dynamic plastic deformation is however less stable than the microstructure after quasi- static compression. Annealing at 675 and 700 degrees C leads to structural coarsening and recrystallisation in each sample, but with recrystallisation...... occurring faster in the sample annealed after dynamic plastic deformation. The lower thermal stability of the microstructure produced by dynamic plastic deformation is attributed to a higher driving force for recrystallisation in the dynamically deformed material....

  12. Crustal deformation mechanism in southeastern Tibetan Plateau: Insights from numerical modeling

    Science.gov (United States)

    Li, Y.; Liu, S.; Chen, L.

    2017-12-01

    The Indo-Asian collision developed the complicated crustal deformation around the southeastern Tibetan plateau. Numerous models have proposed to explain the crustal deformation, but the mechanism remains controversial, especially the increasing multi-geophysics data, which demonstrate the existence of lower velocity, lower resistivity and high conductivity, implying that lower crustal flow is responsible for the crustal deformation, arguing for the lower crust flow model. To address the relations between the crust flow and the surface deformation, we employ a three-dimensional viscoelastic finite model to investigate the possible influence on the surface deformation, and discuss the stress field distribution under the model. Our preliminary results suggest that lower crustal flow plays an important role in crustal deformation in southeastern Tibetan plateau. The best fitting is achieved when the flow velocity of the lower crust is approximately 10-11 mm/a faster than that of the upper crust. Crustal rheological properties affect regional crustal deformation, when the viscosity of the middle and lower crust in the South China block reaches 1022 and 1023 Pa.s, respectively; the predicted match observations well, especially for the magnitude within the South China block. The maximum principal stress field exhibits clear zoning, gradually shifting from an approximately east-west orientation in the northern Bayan Har block to southeast in the South China block, southwest in the western Yunnan block, and a radially divergent distribution in the Middle Yunnan and Southern Yunnan blocks.

  13. Ductile fracture estimation of reactor pressure vessel under thermal shock

    International Nuclear Information System (INIS)

    Takahashi, Jun; Sakai, Shinsuke; Okamura, Hiroyuki

    1990-01-01

    This paper presents a new scheme for the estimation of unstable ductile fracture of a reactor pressure vessel under thermal shock conditions. First, it is shown that the bending moment applied to the cracked section can be evaluated by considering the plastic deformation of the cracked section and the thermal deformation of the shell. As the contribution of the local thermal stress to the J-value is negligible, the J-value under thermal shock can be easily evaluated by using fully plastic solutions for the cracked part. Next, the phenomena of ductile fracture under thermal shock are expressed on the load-versus-displacement diagram which enables us to grasp the transient phenomena visually. In addition, several parametrical surveys are performed on the above diagram concerning the variation of (1) thermal shock conditions, (2) initial crack length, and (3) J-resistance curve (i.e. embrittlement by neutron irradiation). (author)

  14. Gate-tunable gigantic lattice deformation in VO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Okuyama, D., E-mail: okuyama@riken.jp, E-mail: nakano@imr.tohoku.ac.jp, E-mail: iwasa@ap.t.u-tokyo.ac.jp; Hatano, T. [RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan); Nakano, M., E-mail: okuyama@riken.jp, E-mail: nakano@imr.tohoku.ac.jp, E-mail: iwasa@ap.t.u-tokyo.ac.jp [RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan); Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Takeshita, S.; Ohsumi, H.; Tardif, S. [RIKEN SPring-8 Center, Hyogo 679-5148 (Japan); Shibuya, K. [National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8562 (Japan); Yumoto, H.; Koyama, T.; Ohashi, H. [Japan Synchrotron Radiation Research Institute, SPring-8, Hyogo 679-5198 (Japan); Takata, M. [RIKEN SPring-8 Center, Hyogo 679-5148 (Japan); Japan Synchrotron Radiation Research Institute, SPring-8, Hyogo 679-5198 (Japan); Kawasaki, M.; Tokura, Y.; Iwasa, Y., E-mail: okuyama@riken.jp, E-mail: nakano@imr.tohoku.ac.jp, E-mail: iwasa@ap.t.u-tokyo.ac.jp [RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan); Quantum-Phase Electronics Center and Department of Applied Physics, University of Tokyo, Tokyo 113-8656 (Japan); Arima, T. [RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan); RIKEN SPring-8 Center, Hyogo 679-5148 (Japan); Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561 (Japan)

    2014-01-13

    We examined the impact of electric field on crystal lattice of vanadium dioxide (VO{sub 2}) in a field-effect transistor geometry by in-situ synchrotron x-ray diffraction measurements. Whereas the c-axis lattice parameter of VO{sub 2} decreases through the thermally induced insulator-to-metal phase transition, the gate-induced metallization was found to result in a significant increase of the c-axis length by almost 1% from that of the thermally stabilized insulating state. We also found that this gate-induced gigantic lattice deformation occurs even at the thermally stabilized metallic state, enabling dynamic control of c-axis lattice parameter by more than 1% at room temperature.

  15. Theoretical analysis of deformation behavior of aluminum matrix composites in laser forming

    International Nuclear Information System (INIS)

    Liu, F.R.; Chan, K.C.; Tang, C.Y.

    2005-01-01

    In this paper, the deformation behavior of the SiC reinforced aluminum matrix composite in laser forming was investigated. A 2KW Nd:YAG laser was used to deform the composite at different laser powers, scanning speeds, numbers of irradiation passes and beam diameters. It was found that the bending angle increases with an increase in laser power, and a decrease in scanning speed and beam diameter. A relatively linear relationship between bending angle and number of irradiation passes was observed, and the effect of microstructural changes on the deformation behavior was discussed. An analytical model based on the Vollertsen's two-layer model was developed to predict the bending angle of the composite. The trends of the predictions are in good agreement with the experimental results. The effect of reinforcements on deformation behavior of the composite was further theoretically investigated. By modeling the changes of physical, thermal and mechanical properties including yield stress, elastic modulus, surface absorption coefficient and thermal conductivity of the material incorporated with SiC particles, the effect of reinforcement on laser bending angle was analyzed, and it was found that it would result in a larger bending angle. The significance of the findings will be discussed in the paper

  16. Linking plate reconstructions with deforming lithosphere to geodynamic models

    Science.gov (United States)

    Müller, R. D.; Gurnis, M.; Flament, N.; Seton, M.; Spasojevic, S.; Williams, S.; Zahirovic, S.

    2011-12-01

    While global computational models are rapidly advancing in terms of their capabilities, there is an increasing need for assimilating observations into these models and/or ground-truthing model outputs. The open-source and platform independent GPlates software fills this gap. It was originally conceived as a tool to interactively visualize and manipulate classical rigid plate reconstructions and represent them as time-dependent topological networks of editable plate boundaries. The user can export time-dependent plate velocity meshes that can be used either to define initial surface boundary conditions for geodynamic models or alternatively impose plate motions throughout a geodynamic model run. However, tectonic plates are not rigid, and neglecting plate deformation, especially that of the edges of overriding plates, can result in significant misplacing of plate boundaries through time. A new, substantially re-engineered version of GPlates is now being developed that allows an embedding of deforming plates into topological plate boundary networks. We use geophysical and geological data to define the limit between rigid and deforming areas, and the deformation history of non-rigid blocks. The velocity field predicted by these reconstructions can then be used as a time-dependent surface boundary condition in regional or global 3-D geodynamic models, or alternatively as an initial boundary condition for a particular plate configuration at a given time. For time-dependent models with imposed plate motions (e.g. using CitcomS) we incorporate the continental lithosphere by embedding compositionally distinct crust and continental lithosphere within the thermal lithosphere. We define three isostatic columns of different thickness and buoyancy based on the tectonothermal age of the continents: Archean, Proterozoic and Phanerozoic. In the fourth isostatic column, the oceans, the thickness of the thermal lithosphere is assimilated using a half-space cooling model. We also

  17. Full Core Multiphysics Simulation with Offline Mesh Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Merzari, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Shemon, E. R. [Argonne National Lab. (ANL), Argonne, IL (United States); Yu, Y. [Argonne National Lab. (ANL), Argonne, IL (United States); Thomas, J. W. [Argonne National Lab. (ANL), Argonne, IL (United States); Obabko, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Jain, Rajeev [Argonne National Lab. (ANL), Argonne, IL (United States); Mahadevan, Vijay [Argonne National Lab. (ANL), Argonne, IL (United States); Solberg, Jerome [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ferencz, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Whitesides, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-12-21

    In this report, building on previous reports issued in FY13 we describe our continued efforts to integrate thermal/hydraulics, neutronics, and structural mechanics modeling codes to perform coupled analysis of a representative fast sodium-cooled reactor core. The focus of the present report is a full core simulation with off-line mesh deformation.

  18. A mechanical deformation model of metallic fuel pin under steady state conditions

    International Nuclear Information System (INIS)

    Lee, D. W.; Lee, B. W.; Kim, Y. I.; Han, D. H.

    2004-01-01

    As a mechanical deformation model of the MACSIS code predicts the cladding deformation due to the simple thin shell theory, it is impossible to predict the FCMI(Fuel-Cladding Mechanical Interaction). Therefore, a mechanical deformation model used the generalized plane strain is developed. The DEFORM is a mechanical deformation routine which is used to analyze the stresses and strains in the fuel and cladding of a metallic fuel pin of LMRs. The accuracy of the program is demonstrated by comparison of the DEFORM predictions with the result of another code calculations or experimental results in literature. The stress/strain distributions of elastic part under free thermal expansion condition are completely matched with the results of ANSYS code. The swelling and creep solutions are reasonably well agreed with the simulations of ALFUS and LIFE-M codes, respectively. The predicted cladding strains are under estimated than experimental data at the range of high burnup. Therefore, it is recommended that the fine tuning of the DEFORM based on various range of experimental data

  19. Influence of thermal deformation in cavity mirrors on beam propagation characteristics of high-power slab lasers

    Science.gov (United States)

    Wang, Zhen; Xiao, Longsheng; Wang, Wei; Wu, Chao; Tang, Xiahui

    2018-01-01

    Owing to their good diffusion cooling and low sensitivity to misalignment, slab-shape negative-branch unstable-waveguide resonators are widely used for high-power lasers in industry. As the output beam of the resonator is astigmatic, an external beam shaping system is required. However, the transverse dimension of the cavity mirrors in the resonator is large. For a long-time operation, the heating of cavity mirrors can be non-uniform. This results in micro-deformation and a change in the radius of curvature of the cavity mirrors, and leads to an output beam of an offset optical axis of the resonator. It was found that a change in the radius of curvature of 0.1% (1 mm) caused by thermal deformation generates a transverse displacement of 1.65 mm at the spatial filter of the external beam shaping system, and an output power loss of more than 80%. This can potentially burn out the spatial filter. In order to analyze the effect of the offset optical axis of the beam on the external optical path, we analyzed the transverse displacement and rotational misalignments of the spatial filter. For instance, if the transverse displacement was 0.3 mm, the loss in the output power was 9.6% and a sidelobe appeared in the unstable direction. If the angle of rotation was 5°, the loss in the output power was 2%, and the poles were in the direction of the waveguide. Based on these results, by adjusting the bending mirror, the deviation angle of the output beam of the resonator cavity was corrected, in order to obtain maximum output power and optimal beam quality. Finally, the propagation characteristics of the corrected output beam were analyzed.

  20. Modeling thermal inkjet and cell printing process using modified pseudopotential and thermal lattice Boltzmann methods

    Science.gov (United States)

    Sohrabi, Salman; Liu, Yaling

    2018-03-01

    Pseudopotential lattice Boltzmann methods (LBMs) can simulate a phase transition in high-density ratio multiphase flow systems. If coupled with thermal LBMs through equation of state, they can be used to study instantaneous phase transition phenomena with a high-temperature gradient where only one set of formulations in an LBM system can handle liquid, vapor, phase transition, and heat transport. However, at lower temperatures an unrealistic spurious current at the interface introduces instability and limits its application in real flow system. In this study, we proposed new modifications to the LBM system to minimize a spurious current which enables us to study nucleation dynamic at room temperature. To demonstrate the capabilities of this approach, the thermal ejection process is modeled as one example of a complex flow system. In an inkjet printer, a thermal pulse instantly heats up the liquid in a microfluidic chamber and nucleates bubble vapor providing the pressure pulse necessary to eject droplets at high speed. Our modified method can present a more realistic model of the explosive vaporization process since it can also capture a high-temperature/density gradient at nucleation region. Thermal inkjet technology has been successfully applied for printing cells, but cells are susceptible to mechanical damage or death as they squeeze out of the nozzle head. To study cell deformation, a spring network model, representing cells, is connected to the LBM through the immersed boundary method. Looking into strain and stress distribution of a cell membrane at its most deformed state, it is found that a high stretching rate effectively increases the rupture tension. In other words, membrane deformation energy is released through creation of multiple smaller nanopores rather than big pores. Overall, concurrently simulating multiphase flow, phase transition, heat transfer, and cell deformation in one unified LB platform, we are able to provide a better insight into the

  1. Modeling thermal inkjet and cell printing process using modified pseudopotential and thermal lattice Boltzmann methods.

    Science.gov (United States)

    Sohrabi, Salman; Liu, Yaling

    2018-03-01

    Pseudopotential lattice Boltzmann methods (LBMs) can simulate a phase transition in high-density ratio multiphase flow systems. If coupled with thermal LBMs through equation of state, they can be used to study instantaneous phase transition phenomena with a high-temperature gradient where only one set of formulations in an LBM system can handle liquid, vapor, phase transition, and heat transport. However, at lower temperatures an unrealistic spurious current at the interface introduces instability and limits its application in real flow system. In this study, we proposed new modifications to the LBM system to minimize a spurious current which enables us to study nucleation dynamic at room temperature. To demonstrate the capabilities of this approach, the thermal ejection process is modeled as one example of a complex flow system. In an inkjet printer, a thermal pulse instantly heats up the liquid in a microfluidic chamber and nucleates bubble vapor providing the pressure pulse necessary to eject droplets at high speed. Our modified method can present a more realistic model of the explosive vaporization process since it can also capture a high-temperature/density gradient at nucleation region. Thermal inkjet technology has been successfully applied for printing cells, but cells are susceptible to mechanical damage or death as they squeeze out of the nozzle head. To study cell deformation, a spring network model, representing cells, is connected to the LBM through the immersed boundary method. Looking into strain and stress distribution of a cell membrane at its most deformed state, it is found that a high stretching rate effectively increases the rupture tension. In other words, membrane deformation energy is released through creation of multiple smaller nanopores rather than big pores. Overall, concurrently simulating multiphase flow, phase transition, heat transfer, and cell deformation in one unified LB platform, we are able to provide a better insight into the

  2. A Novel Method of Modeling the Deformation Resistance for Clad Sheet

    International Nuclear Information System (INIS)

    Hu Jianliang; Yi Youping; Xie Mantang

    2011-01-01

    Because of the excellent thermal conductivity, the clad sheet (3003/4004/3003) of aluminum alloy is extensively used in various heat exchangers, such as radiator, motorcar air conditioning, evaporator, and so on. The deformation resistance model plays an important role in designing the process parameters of hot continuous rolling. However, the complex behaviors of the plastic deformation of the clad sheet make the modeling very difficult. In this work, a novel method for modeling the deformation resistance of clad sheet was proposed by combining the finite element analysis with experiments. The deformation resistance model of aluminum 3003 and 4004 was proposed through hot compression test on the Gleeble-1500 thermo-simulation machine. And the deformation resistance model of clad sheet was proposed through finite element analysis using DEFORM-2D software. The relationship between cladding ratio and the deformation resistance was discussed in detail. The results of hot compression simulation demonstrate that the cladding ratio has great effects on the resistance of the clad sheet. Taking the cladding ratio into consideration, the mathematical model of the deformation resistance for clad sheet has been proved to have perfect forecasting precision of different cladding ratio. Therefore, the presented model can be used to predict the rolling force of clad sheet during the hot continuous rolling process.

  3. Organ Surface Deformation Measurement and Analysis in Open Hepatic Surgery: Method and Preliminary Results From 12 Clinical Cases

    OpenAIRE

    Clements, Logan W.; Dumpuri, Prashanth; Chapman, William C.; Dawant, Benoit M.; Galloway, Robert L.; Miga, Michael I.

    2011-01-01

    The incidence of soft tissue deformation has been well documented in neurosurgical procedures and is known to compromise the spatial accuracy of image-guided surgery systems. Within the context of image-guided liver surgery (IGLS), no detailed method to study and analyze the observed organ shape change between preoperative imaging and the intraoperative presentation has been developed. Contrary to the studies of deformation in neurosurgical procedures, the majority of deformation in IGLS is i...

  4. Preliminary development of thermal nuclear cell homogenization code

    International Nuclear Information System (INIS)

    Su'ud, Z.; Shafii, M. A.; Yudha, S. P.; Waris, A.; Rijal, K.

    2012-01-01

    Nuclear fuel cell homogenization for thermal reactors usually include three main parts, i.e., fast energy resonance part which usually adopt narrow resonance approximation to treat the resonance, low (intermediate) energy region in which the resonance can not be treated accurately using NR approximation and therefore we should use intermediate resonance treatment, and thermal energy region (very low) in which the effect of thermal must be treated properly. In n this study the application of the intermediate resonance approximation treatment for low energy nuclear resonance is discussed. The method is iterative based. As a sample the method is applied in U-235 low lying resonance and the result is presented and discussed.

  5. On the effect of brazing thermal cycle on the properties of niobium and its alloys

    International Nuclear Information System (INIS)

    Grishin, V.L.; Cherkasov, A.F.

    1975-01-01

    The effect of the main parameters of the soldering thermal cycle on the properties of Nb and its alloys was studied by heating the samples under modelled conditions of soldering. The studies were made on commercial VN-niobium, alloys of the Nb-Mo-Zr system VN2A, VN2AEHM) and alloys of the Nb-Mo-Zr-C system (VN5AEH,VN5A). The degree of a preliminary plastic deformation of samples 0.3 to 0.8 mm thick made up 60 to 80%. The heating was made in vacuum (10 -4 to 5x10 -5 mm Hg) or in argon by passing the electric current across the samples. After heating a metallographic study and X-ray electron-probe analysis were made. The studies have shown that the changes in the heating rate result in a proportional change in the recrystallization initiation temperature. At a heating rate 300 deg C/s the recrystallization initiation temperature of commercial Nb is 930 to 960 deg as soon as the heating rate increases up to 900 deg/c the recrystallization initiation temperature rises up to about 1200 deg C. The heating temperature effect on the mechanical characteristics of commercial Nb and alloys VN2, VN2AEH and VN5AEH is shown. It is found that soldered joints of Nb and its alloys could be made of good quality when observing the thermal cycles ensuring the minimum softening of the base material. The main factors affecting the properties of Nb and alloy-VN2 are the heating temperature and the extent of a preliminary cold deformation. In a more deformed material the annealing results in the activation of the recrystallization processes. The production of high-strength soldered joints of commercial Nb is possible at the soldering temperature equal to 1100 deg C, but of Nb-Mo-Zr alloys-at 1200 to 1300 deg C and hold-up periods not exceeding one hour. A heterophase structure of alloys of the Nb-Mo-Zr-C system and the presence of Mo- and Zr-carbide phases in them result in a considerable hardening of the alloys and the increase in their recrystallization temperature. The usage of alloys

  6. Recovery by triple junction motion in aluminium deformed to ultrahigh strains

    DEFF Research Database (Denmark)

    Yu, Tianbo; Hansen, Niels; Huang, Xiaoxu

    2011-01-01

    during plastic deformation and decreases during isochronal and isothermal annealing. Based on TEM and EBSD observations, thermally activated triple junction motion is identified as the key process during the recovery of highly strained aluminium, leading to the removal of thin lamellae with small...... dihedral angles at the ends and structural coarsening. A mechanism for recovery by triple junction motion is proposed, which can underpin the general observation that a lamellar structure formed by plastic deformation during annealing can evolve into an equiaxed structure, preceding further structural...... coarsening and recrystallization. Within this framework, the grain boundary surface tension on triple junctions is discussed based on the structural parameters characterizing the deformed and annealed microstructure....

  7. Thermal Properties of G-348 Graphite

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, Donald M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Swank, W. David [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cottle, David L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Valentin, Francisco I. [City Univ. (CUNY), NY (United States)

    2017-04-01

    Fundamental measurements have been obtained in the INL Graphite Characterization Laboratory to deduce the temperature dependence of thermal conductivity for G-348 isotropic graphite, which has been used by City College of New York in thermal experiments related to gas-cooled nuclear reactors. Measurements of thermal diffusivity, mass, volume and thermal expansion were converted to thermal conductivity in accordance with ASTM Standard Practice C781-08 (R-2014). Data are tabulated and a preliminary correlation for the thermal conductivity is presented as a function of temperature from laboratory temperature to 1000C.

  8. Preliminary Analysis of the Fuel Bundle Stiffness by ANSYS for SFR

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byoung Oon; Cheon, Jin Sik; Hahn, Do Hee; Lee, Chan Bock [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-05-15

    In SFR (Sodium-cooled Fast Reactor) the temperature of the fuel pin is higher than that of the hexagonal duct, so the thermal expansion rate of the fuel bundle is higher than that of the duct. The neutron fluence and the fuel pin pressure are also increased according to the burnup. So the radial expansion and bowing of a fuel pin bundle would occur, and then fuel bundle would interact with a duct. This phenomenon is called bundle-to-duct interaction (BDI). Under the BDI condition, excess cladding strain and hot spots would occur. Therefore BDI as well as the core mechanics should be considered to evaluate the FBR fuel integrity. The analysis codes such as ETOILE, SHADOW, and MARSE, have been developed to evaluate the BDI behavior. The ANSYS based model is also being developed to analysis the bundle duct interaction for SFR in Korea. In this paper, the fuel pin/bundle model for analyzing the bending deflection and oval deformation was described. The preliminary analysis of the fuel bundle stiffness was performed by the developed model.

  9. Holographic thermal DC response in the hydrodynamic limit

    Science.gov (United States)

    Banks, Elliot; Donos, Aristomenis; Gauntlett, Jerome P.; Griffin, Tom; Melgar, Luis

    2017-02-01

    We consider black hole solutions of Einstein gravity that describe deformations of CFTs at finite temperature in which spatial translations have been broken explicitly. We focus on deformations that are periodic in the non-compact spatial directions, which effectively corresponds to considering the CFT on a spatial torus with a non-trivial metric. We apply a DC thermal gradient and show that in a hydrodynamic limit the linearised, local thermal currents can be determined by solving linearised, forced Navier-Stokes equations for an incompressible fluid on the torus. We also show how sub-leading corrections to the thermal current can be calculated as well as showing how the full stress tensor response that is generated by the DC source can be obtained. We also compare our results with the fluid-gravity approach.

  10. Preliminary research on virtual thermal comfort of automobile occupants

    Science.gov (United States)

    Horobet, Tiberiu; Danca, Paul; Nastase, Ilinca; Bode, Florin

    2018-02-01

    Numerical simulation of climate conditions in automotive industry for the study of thermal comfort had become more and more prominent in the last years compared with the classical approach which consists in wind tunnel measurements and field testing, the main advantages being the reduction of vehicle development time and costs. The study presented in this paper is a part of a project intended to evaluate different strategies of cabin ventilation for improving the thermal comfort inside vehicles. A virtual thermal manikin consisting of 24 parts was introduced on the driver seat in a vehicle. A heat load calculated for summer condition in the city of Cluj-Napoca, Romania was imposed as boundary condition. The purpose of this study was to elaborate a virtual thermal manikin suitable for our research, introduction of the manikin inside the vehicle and to examine his influence inside the automobile. The thermal comfort of the virtual manikin was evaluated in terms of temperature and air velocity.

  11. Ongoing Deformation of Sinkholes in Wink, Texas, Observed by Time-Series Sentinel-1A SAR Interferometry (Preliminary Results

    Directory of Open Access Journals (Sweden)

    Jin-Woo Kim

    2016-04-01

    Full Text Available Spatiotemporal deformation of existing sinkholes and the surrounding region in Wink, TX are probed using time-series interferometric synthetic aperture radar (InSAR methods with radar images acquired from the Sentinel-1A satellite launched in April 2014. The two-dimensional deformation maps, calculated using InSAR observations from ascending and descending tracks, reveal that much of the observed deformation is vertical. Our results indicate that the sinkholes are still influenced by ground depression, implying that the sinkholes continue to expand. Particularly, a region 1 km northeast of sinkhole #2 is sinking at a rate of up to 13 cm/year, and its aerial extent has been enlarged in the past eight years when compared with a previous survey. Furthermore, there is a high correlation between groundwater level and surficial subsidence during the summer months, representing the complicated characteristics of sinkhole deformation under the influence of successive roof failures in underlying cavities. We also modeled the sinkhole deformation in a homogenous elastic half-space with two dislocation sources, and the ground depression above cavities could be numerically analyzed. Measurements of ongoing deformation in sinkholes and assessments of the stability of the land surface at sinkhole-prone locations in near real-time, are essential for mitigating the threat posed to people and property by the materialization of sinkholes.

  12. Thermally-assisted Magma Emplacement Explains Restless Calderas

    Science.gov (United States)

    Amoruso, A.; Crescentini, L.; D'Antonio, M.; Acocella, V.

    2017-12-01

    Many calderas show repeated unrest over centuries. Though probably induced by magma, this unique behaviour is not understood and its dynamics remains elusive. To better understand these restless calderas, we interpret deformation data and build thermal models of Campi Flegrei, Italy, which is the best-known, yet most dangerous calderas, lying to the west of Naples and restless since the 1950s at least.Our elaboration of the geodetic data indicates that the inflation and deflation of magmatic sources at the same location explain most deformation, at least since the build-up of the last 1538 AD eruption. However, such a repeated magma emplacement requires a persistently hot crust.Our thermal models show that the repeated emplacement was assisted by the thermal anomaly created by magma that was intruded at shallow depth 3 ka before the last eruption and, in turn, contributed to maintain the thermal anomaly itself. This may explain the persistence of the magmatic sources promoting the restless behaviour of the Campi Flegrei caldera; moreover, it explains the crystallization, re-melting and mixing among compositionally distinct magmas recorded in young volcanic rocks.Available information at other calderas highlights similarities to Campi Flegrei, in the pattern and cause of unrest. All monitored restless calderas have either geodetically (Yellowstone, Aira Iwo-Jima, Askja, Fernandina and, partly, Long Valley) or geophysically (Rabaul, Okmok) detected sill-like intrusions inducing repeated unrest. Some calderas (Yellowstone, Long Valley) also show stable deformation pattern, where inflation insists on and mimics the resurgence uplift. The common existence of sill-like sources, also responsible for stable deformation patterns, in restless calderas suggests close similarities to Campi Flegrei. This suggests a wider applicability of our model of thermally-assisted sill emplacement, to be tested by future studies to better understand not only the dynamics of restless

  13. Hot Deformation Behavior of 1Cr12Ni3Mo2VN Martensitic Stainless Steel

    Science.gov (United States)

    He, Xiaomao; Jiang, Peng; Zhou, Leyu; Chen, Chao; Deng, Xiaochun

    2017-08-01

    1Cr12Ni3Mo2VN is a new type of martensitic stainless steel for the last-stage blades of large-capacity nuclear and thermal power turbines. The deformation behavior of this steel was studied by thermal compression experiments that performed on a Gleeble-3500 thermal simulator at a temperature range of 850°C to 1200°C and a strain rate of 0.01s-1 to 20s-1. When the deformation was performed at high temperature and low strain rate, a necklace type of microstructures was observed, the plastic deformation mechanism is grain boundary slip and migration, when at low temperature and lower strain rate, the slip bands were observed, the mechanism is intracrystalline slips, and when at strain rate of 20s-1, twins were observed, the mechanism are slips and twins. The Arrhenius equation was applied to describe the constitutive equation of the flow stress. The accuracy of the equation was verified by using the experimental data and the correlation coefficient R2 = 0.9786, and the equation can provide reasonable data for the design and numerical simulation of the forging process.

  14. Evaluation of structural deformations of a mechanical connecting unit oxidizer supplies by thermo-mechanical simulation

    International Nuclear Information System (INIS)

    Kim, Sang Woo

    2016-01-01

    A Mechanical connecting unit (MCU) used in ground facilities for a Liquid propellant rocket (LPR) acts as a bridge between the onboard system and the ground oxidizer filling system. It should be resistant to structural deformations in order to guarantee successful supply of a cryogenic oxidizer and high pressure gases without reduction of sealing capability. The MCU consists of many components and linkages and operates under harsh conditions induced by a cryogenic oxidizer, high pressure gases and other mechanical forces. Thus, the evaluation of structural deformation of the MCU considering complex conditions is expensive and time consuming. The present study efficiently evaluates the structural deformations of the key components of the MCU by Thermo-mechanical simulation (TMS) based on the superposition principle. Deformations due to the mechanical loadings including weights, pressures, and spring forces are firstly evaluated by using a non-linear flexible body simulation module (FFlex) of Multi-body dynamics (MBD) software, RecurDyn. Then, thermal deformations for the deformed geometries obtained by RecurDyn were subsequently calculated. It was conducted by using a Finite element (FE) analysis software, ANSYS. The total deformations for the onboard plate and multi-channel plate in the connecting section due to the mechanical and thermal loadings were successfully evaluated. Moreover, the outer gaps at six points between two plates were calculated and verified by comparison to the measured data. Their values and tendencies showed a good agreement. The author concluded that the TMS using MBD software considering flexible bodies and an FE simulator can efficiently evaluate structural deformations of the MCU operating under the complex load and boundary conditions

  15. Evaluation of structural deformations of a mechanical connecting unit oxidizer supplies by thermo-mechanical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Woo [Dept. of Mechanical Engineering, Institute of Machine Convergence Technology, Hankyong National University, Anseong (Korea, Republic of)

    2016-10-15

    A Mechanical connecting unit (MCU) used in ground facilities for a Liquid propellant rocket (LPR) acts as a bridge between the onboard system and the ground oxidizer filling system. It should be resistant to structural deformations in order to guarantee successful supply of a cryogenic oxidizer and high pressure gases without reduction of sealing capability. The MCU consists of many components and linkages and operates under harsh conditions induced by a cryogenic oxidizer, high pressure gases and other mechanical forces. Thus, the evaluation of structural deformation of the MCU considering complex conditions is expensive and time consuming. The present study efficiently evaluates the structural deformations of the key components of the MCU by Thermo-mechanical simulation (TMS) based on the superposition principle. Deformations due to the mechanical loadings including weights, pressures, and spring forces are firstly evaluated by using a non-linear flexible body simulation module (FFlex) of Multi-body dynamics (MBD) software, RecurDyn. Then, thermal deformations for the deformed geometries obtained by RecurDyn were subsequently calculated. It was conducted by using a Finite element (FE) analysis software, ANSYS. The total deformations for the onboard plate and multi-channel plate in the connecting section due to the mechanical and thermal loadings were successfully evaluated. Moreover, the outer gaps at six points between two plates were calculated and verified by comparison to the measured data. Their values and tendencies showed a good agreement. The author concluded that the TMS using MBD software considering flexible bodies and an FE simulator can efficiently evaluate structural deformations of the MCU operating under the complex load and boundary conditions.

  16. A novel deformation mechanism for superplastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Muto, H.; Sakai, M. (Toyohashi Univ. of Technology (Japan). Dept. of Materials Science)

    1999-01-01

    Uniaxial compressive creep tests with strain value up to -0.1 for a [beta]-spodumene glass ceramic are conducted at 1060 C. From the observation of microstructural changes between before and after the creep deformations, it is shown that the grain-boundary sliding takes place via cooperative movement of groups of grains rather than individual grains under the large-scale-deformation. The deformation process and the surface technique used in this work are not only applicable to explain the deformation and flow of two-phase ceramics but also the superplastic deformation. (orig.) 12 refs.

  17. Microstructure and properties of 700 MPa grade HSLA steel during high temperature deformation

    International Nuclear Information System (INIS)

    Chen, Xizhang; Huang, Yuming; Lei, Yucheng

    2015-01-01

    Highlights: • Hot deformation behavior of 700 MPa HSLA steel above 1200 °C in was detailed studied. • Uniform and granular bainite is formed when the deformation amount is 40%. • Deformation resistance value under steady-equilibrium state is about 56 MPa. - Abstract: A high temperature deformation experiment was conducted on a high strength low alloy (HSLA) steel Q690 using Thermecmastor-Z thermal/physical simulator. During the experiment, the specimens were heated from room temperature to 1200 °C with the heating rate of 10 °C/s and 50 °C/s, respectively. The deformation temperature was 1200 °C and the deformation amounts were 0%, 10% and 40%, respectively. The microstructures, stress–strain diagram and hardness were obtained. The results revealed that the microstructure transformation of deformed austenite was quite different from that of the normal situation. With the increasing of deformation amount, more lath-shaped microstructure and less granulous microstructure were observed. The compressive deformation effectively prevented the precipitation of carbides. Larger deformation amount or lower heating rate was conducive to the atomic diffusion, which led to the microstructure uniformity and hardness decreasing. The maximum stress was 68.4 MPa and the steady stress was about 56 MPa

  18. Thermally-assisted Magma Emplacement Explains Restless Calderas.

    Science.gov (United States)

    Amoruso, Antonella; Crescentini, Luca; D'Antonio, Massimo; Acocella, Valerio

    2017-08-11

    Many calderas show repeated unrest over centuries. Though probably induced by magma, this unique behaviour is not understood and its dynamics remains elusive. To better understand these restless calderas, we interpret deformation data and build thermal models of Campi Flegrei caldera, Italy. Campi Flegrei experienced at least 4 major unrest episodes in the last decades. Our results indicate that the inflation and deflation of magmatic sources at the same location explain most deformation, at least since the build-up of the last 1538 AD eruption. However, such a repeated magma emplacement requires a persistently hot crust. Our thermal models show that this repeated emplacement was assisted by the thermal anomaly created by magma that was intruded at shallow depth ~3 ka before the last eruption. This may explain the persistence of the magmatic sources promoting the restless behaviour of the Campi Flegrei caldera; moreover, it explains the crystallization, re-melting and mixing among compositionally distinct magmas recorded in young volcanic rocks. Our model of thermally-assisted unrest may have a wider applicability, possibly explaining also the dynamics of other restless calderas.

  19. Formation Flying and Deformable Instruments

    International Nuclear Information System (INIS)

    Rio, Yvon

    2009-01-01

    Astronomers have always attempted to build very stable instruments. They fight all that can cause mechanical deformation or image motion. This has led to well established technologies (autoguide, active optics, thermal control, tip/tilt correction), as well as observing methods based on the use of controlled motion (scanning, micro scanning, shift and add, chopping and nodding). Formation flying disturbs this practice. It is neither possible to reduce the relative motion to very small amplitudes, nor to control it at will. Some impacts on Simbol-X instrument design, and operation are presented.

  20. Formation Flying and Deformable Instruments

    Science.gov (United States)

    Rio, Yvon

    2009-05-01

    Astronomers have always attempted to build very stable instruments. They fight all that can cause mechanical deformation or image motion. This has led to well established technologies (autoguide, active optics, thermal control, tip/tilt correction), as well as observing methods based on the use of controlled motion (scanning, micro scanning, shift and add, chopping and nodding). Formation flying disturbs this practice. It is neither possible to reduce the relative motion to very small amplitudes, nor to control it at will. Some impacts on Simbol-X instrument design, and operation are presented.

  1. On the rolling of hard-to-work iron-cobalt alloys with application of electric current of high density

    International Nuclear Information System (INIS)

    Klimov, K.M.; Mordukhovich, A.M.; Glezer, A.M.; Molotilov, B.V.

    1981-01-01

    Results on experimental fabrication of thin sheets of commercial iron-cobalt 49KF alloy (Se-Co-2%V) without preliminary quenching and intermediate annealings by rolling with application of high-density electric current are considered. It is shown that rolling with application of high-density electric current in the deformation zone permits to obtain thin sheets of difficult-to-form magnetically soft materials without preliminary thermal treatments. Electric current effect on metal in the deformation zone results in the increase of dislocation mobility and facilitates the cross glide [ru

  2. Thermal conductivity of graphene nanoribbons under shear deformation: A molecular dynamics simulation

    Science.gov (United States)

    Zhang, Chao; Hao, Xiao-Li; Wang, Cui-Xia; Wei, Ning; Rabczuk, Timon

    2017-01-01

    Tensile strain and compress strain can greatly affect the thermal conductivity of graphene nanoribbons (GNRs). However, the effect of GNRs under shear strain, which is also one of the main strain effect, has not been studied systematically yet. In this work, we employ reverse nonequilibrium molecular dynamics (RNEMD) to the systematical study of the thermal conductivity of GNRs (with model size of 4 nm × 15 nm) under the shear strain. Our studies show that the thermal conductivity of GNRs is not sensitive to the shear strain, and the thermal conductivity decreases only 12–16% before the pristine structure is broken. Furthermore, the phonon frequency and the change of the micro-structure of GNRs, such as band angel and bond length, are analyzed to explore the tendency of thermal conductivity. The results show that the main influence of shear strain is on the in-plane phonon density of states (PDOS), whose G band (higher frequency peaks) moved to the low frequency, thus the thermal conductivity is decreased. The unique thermal properties of GNRs under shear strains suggest their great potentials for graphene nanodevices and great potentials in the thermal managements and thermoelectric applications. PMID:28120921

  3. Reducing residual stresses and deformations in selective laser melting through multi-level multi-scale optimization of cellular scanning strategy

    DEFF Research Database (Denmark)

    Mohanty, Sankhya; Hattel, Jesper Henri

    2016-01-01

    . A multilevel optimization strategy is adopted using a customized genetic algorithm developed for optimizing cellular scanning strategy for selective laser melting, with an objective of reducing residual stresses and deformations. The resulting thermo-mechanically optimized cellular scanning strategies......, a calibrated, fast, multiscale thermal model coupled with a 3D finite element mechanical model is used to simulate residual stress formation and deformations during selective laser melting. The resulting reduction in thermal model computation time allows evolutionary algorithm-based optimization of the process...

  4. Preliminary Thermohydraulic Analysis of a New Moderated Reactor Utilizing an LEU-Fuel for Space Nuclear Thermal Propulsion

    International Nuclear Information System (INIS)

    Nam, Seung Hyun; Choi, Jae Young; Venneria, Paolo F.; Jeong, Yong Hoon; Chang, Soon Heung

    2015-01-01

    The Korea Advanced NUclear Thermal Engine Rocket utilizing an LEU fuel (KANUTER-LEU) is a non-proliferative and comparably efficient NTR engine with relatively low thrust levels of 40 - 50 kN for in-space transportation. The small modular engine can expand mission versatility, when flexibly used in a clustered engine arrangement, so that it can perform various scale missions from low-thrust robotic science missions to high-thrust manned missions. In addition, the clustered engine system can enhance engine redundancy and ensuing crew safety as well as the thrust. The propulsion system is an energy conversion system to transform the thermal energy of the reactor into the kinetic energy of the propellant to produce the powers for thrust, propellant feeding and electricity. It is mainly made up of a propellant Feeding System (PFS) comprising a Turbo-Pump Assembly (TPA), a Regenerative Nozzle Assembly (RNA), etc. For this core design study, an expander cycle is assumed to be the propulsion system. The EGS converts the thermal energy of the EHTGR in the idle operation (only 350 kW th power) to electric power during the electric power mode. This paper presents a preliminary thermohydraulic design analysis to explore the design space for the new reactor and to estimate the referential engine performance. The new non-proliferative NTR engine concept, KANUTER-LEU, is under designing to surmount the nuclear proliferation obstacles on allR and Dactivities and eventual commercialization for future generations. To efficiently implement a heavy LEU fuel for the NTR engine, its reactor design innovatively possesses the key characteristics of the high U density fuel with high heating and H 2 corrosion resistances, the thermal neutron spectrum core and also minimizing non-fission neutron loss, and the compact reactor design with protectively cooling capability. To investigate feasible design space for the moderated EHTGR-LEU and resultant engine performance, the preliminary design

  5. Comparative performance study of smart structure for thermal microactuators

    Science.gov (United States)

    Yahya, Zulkarnain; Johar, Muhammad Akmal

    2017-04-01

    Thermal microactuator is one of earliest types of microactuators. Typical thermal actuators are in the form of Bimorph and Chevron structures. A bimorph thermal actuator has a complex movement direction, in arc motion and thus it is not feasible in the most MEMS designs. While Chevron actuator has a tendency to produce an off-plane movement which lead to low precision in lateral movement. A new thermal actuator design in the form of serpentine structures shows promising feature to have better performances in terms of more predictive lateral movement with smaller off-plane displacement. In MEMS chip design, areas play a critical role as it will impact with the cost of the final product. In this study, four different structures of thermal actuator were simulated using ANSYS v15. Three different set of area sizes which are 240 µm x 1000 µm, 240 µm x 1500 µm and 240 µm x 2000 µm have been analyzed. All four structures were named as Serpentine01, Serpentine02, Bimorph and Chevron. The data with regards to temperature produced by the structure and z-axis directional deformation were collected and analyzed. This paper reported the investigation result of comparison between these three types of thermal actuator structures design with a given area. From all of the result obtained, it is shown that the area 240 µm x 1500 µm showed a well balance performance in term of huge deformations and low power consumption. The Serpentine01 structure produced 16.7 µm deformation at 4mA of current. The results shows the potential of Serpentine01 structure as a new candidate for thermal microactuator for MEMS applications.

  6. On the estimation of durability during thermal fatigue tests

    International Nuclear Information System (INIS)

    Vashunin, A.I.; Kotov, P.I.

    1981-01-01

    It is shown that during thermal fatigue tests under conditions of varying loading rigidity the value of stored one-sided deformation in a fracture zone tends to the limit value of material ductility. Holding at Tsub(max) is semicycle of compression increases irreversible deformation on value of Atausub(confer)sup(a), which does not depend on loading rigidity. It is established that the Use of curves of thermal fatigue as basic ones for determination of resistance of non-isothermal low-cycle fatigue is possible only at values of stored quasistatical damage, constituting less than 5% from available ductility [ru

  7. GROUND DEFORMATION EXTRACTION USING VISIBLE IMAGES AND LIDAR DATA IN MINING AREA

    Directory of Open Access Journals (Sweden)

    W. Hu

    2016-06-01

    Full Text Available Recognition and extraction of mining ground deformation can help us understand the deformation process and space distribution, and estimate the deformation laws and trends. This study focuses on the application of ground deformation detection and extraction combining with high resolution visible stereo imagery, LiDAR observation point cloud data and historical data. The DEM in large mining area is generated using high-resolution satellite stereo images, and ground deformation is obtained through time series analysis combined with historical DEM data. Ground deformation caused by mining activities are detected and analyzed to explain the link between the regional ground deformation and local deformation. A district of covering 200 km2 around the West Open Pit Mine in Fushun of Liaoning province, a city located in the Northeast China is chosen as the test area for example. Regional and local ground deformation from 2010 to 2015 time series are detected and extracted with DEMs derived from ZY-3 images and LiDAR point DEMs in the case study. Results show that the mean regional deformation is 7.1 m of rising elevation with RMS 9.6 m. Deformation of rising elevation and deformation of declining elevation couple together in local area. The area of higher elevation variation is 16.3 km2 and the mean rising value is 35.8 m with RMS 15.7 m, while the deformation area of lower elevation variation is 6.8 km2 and the mean declining value is 17.6 m with RMS 9.3 m. Moreover, local large deformation and regional slow deformation couple together, the deformation in local mining activities has expanded to the surrounding area, a large ground fracture with declining elevation has been detected and extracted in the south of West Open Pit Mine, the mean declining elevation of which is 23.1 m and covering about 2.3 km2 till 2015. The results in this paper are preliminary currently; we are making efforts to improve more precision results with

  8. Computation of deformations and stresses in graphite blocks for HTR core survey purposes

    International Nuclear Information System (INIS)

    Besdo, Dieter; Theymann, W.

    1975-01-01

    Stresses and deformations in graphite fuel elements for HTRs are caused by the temperature distribution and by irradiation under influence of creep, shrinking, thermal strains, and elastic deformations. The global deformations and the stress distribution in a prismatic fuel-element containing regularly distributed axial holes for the coolant flow and the fuel sticks, can be computed in the following manner: the block with its holes is treated as an effective homogeneous continuum with an equivalent global behaviour. Assuming that the fourth-order-tensor of the elastic constants is proportional to the corresponding tensor in the constitutive equations for creep, only the effective strains are of interest. The values of temperature and dose may be given in n points of the block at certain points of time. Then, the inelastic nonthermal strains are integrated by a Runge-Kutta-procedure in the n points. When interpolated and combined with thermal strains, they are incompatible. Hence, they produce elastic deformations which cause creep and can be computed by use of a Ritz-polynomial-series by help of a specific principle of the minimum of potential energy. Excessive computing time can be avoided easily since the influence of the local variation of the elastic constants within the block is almost negligible and, therefore, of practically no importance for the determination of the elastic strains. By this reason some matrices can be calculated a priori, and the elastic deformations are obtained by multiplications of these matrices rather than inversions. Therefore, this method is particularly suited for the computation of deformations and stresses for reactor core survey purposes where a large number (up to 7000 blocks) have to be treated

  9. GAPCON-THERMAL-3

    International Nuclear Information System (INIS)

    Mohr, C.L.; Lanning, D.D.; Panisko, F.E.

    1979-01-01

    The fuel performance code GAPCON-THERMAL-3 has been expanded to include recent transient material deformation constitutive relations and the FLECHT heat transfer correlation. The modifications make it possible to compute the thermal and mechanical response of nuclear fuel to postulated Loss of Coolant Accidents (LOCA). The numerical formulation has the capability of predicting both steady state and transient behavior of a fuel rod using a single analytical procedure. GAPCON-THERMAL-3 (G-T-3) uses a specialized finite element procedure for mechanics predictions and the method of weighted residuals and finite difference techniques to compute temperature and thermal behavior. Fuel behavior, gas release models, gas conductance models, and stored energy calculations are applicable to both steady state and transient conditions. The code has been used to perform scoping analysis for in-reactor LOCA simulation testing. (orig.)

  10. Thermomechanical Modeling of Laser-Induced Structural Relaxation and Deformation of Glass: Volume Changes in Fused Silica at High Temperatures [Thermo-mechanical modeling of laser-induced structural relaxation and deformation of SiO2 glass

    Energy Technology Data Exchange (ETDEWEB)

    Vignes, Ryan M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Soules, Thomas F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Stolken, James S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Settgast, Randolph R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Elhadj, Selim [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Matthews, Manyalibo J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Mauro, J.

    2012-12-17

    In a fully coupled thermomechanical model of the nanoscale deformation in amorphous SiO2 due to laser heating is presented. Direct measurement of the transient, nonuniform temperature profiles was used to first validate a nonlinear thermal transport model. Densification due to structural relaxation above the glass transition point was modeled using the Tool-Narayanaswamy (TN) formulation for the evolution of structural relaxation times and fictive temperature. TN relaxation parameters were derived from spatially resolved confocal Raman scattering measurements of Si–O–Si stretching mode frequencies. These thermal and microstructural data were used to simulate fictive temperatures which are shown to scale nearly linearly with density, consistent with previous measurements from Shelby et al. Volumetric relaxation coupled with thermal expansion occurring in the liquid-like and solid-like glassy states lead to residual stresses and permanent deformation which could be quantified. But, experimental surface deformation profiles between 1700 and 2000 K could only be reconciled with our simulation by assuming a roughly 2 × larger liquid thermal expansion for a-SiO2 with a temperature of maximum density ~150 K higher than previously estimated by Bruckner et al. Calculated stress fields agreed well with recent laser-induced critical fracture measurements, demonstrating accurate material response prediction under processing conditions of practical interest.

  11. Preliminary results on variations of radon concentration associated with rock deformation in a uranium mine

    Science.gov (United States)

    Verdoya, Massimo; Bochiolo, Massimo; Chiozzi, Paolo; Pasquale, Vincenzo; Armadillo, Egidio; Rizzello, Daniele; Chiaberto, Enrico

    2013-04-01

    located next to the Ligurian Sea coast. When the sea tides change the water level at the shore, this might produce additional pressure which increases the deformations (sea loading). This paper presents the preliminary results of an experiment, which is in progress in the uranium mine. During the experiment, several geophysical parameters are monitored together with radon concentration. After appropriate insulation in order to prevent radon escape through normal atmospheric circulation, the gallery was equipped with three radon detectors, four passive dosimeters, an array of unpolarisable electrodes for measurements of self-potential variations and a microgravimeter for monitoring of the tidal effect. We expect that changes in the mechanical state can be accompanied by changes in the electric potential. Since the latter variation can be related also to changes in the natural magnetic field, measurements with a three components fluxgate magnetometer are also being carried out. The recorded signals will be analysed according to standard procedures, such as spectral analysis and cross-correlation, aimed at discriminating the periodic components and the governing physical processes.

  12. Preliminary geotechnical evaluation of deep borehole facilities for nuclear waste disposal in shales

    International Nuclear Information System (INIS)

    Nataraj, M.S.; New Orleans Univ., LA

    1991-01-01

    This study is concerned with a preliminary engineering evaluation of borehole facilities for nuclear waste disposal in shales. Some of the geotechnical properties of Pierre, Rhinestreet, and typical illite shale have been collected. The influence of a few geotechnical properties on strength and deformation of host material is briefly examined. It appears that Pierre shale is very unstable and requires support to prevent collapse. Typical illite shale is more stable than Rhinestreet shale, although it undergoes relatively more deformation. 16 refs., 5 figs., 3 tabs

  13. Debris extrusion and foraminal deformation produced by reciprocating instruments made of thermally treated NiTi wires.

    Science.gov (United States)

    Frota, Myrna Maria Arcanjo; Bernardes, Ricardo Affonso; Vivan, Rodrigo Ricci; Vivacqua-Gomes, Nilton; Duarte, Marco Antonio Hungaro; Vasconcelos, Bruno Carvalho de

    2018-01-18

    To evaluate the amount of apically extruded debris, percentage of foraminal enlargement and apical foramen (AF) deformation that occurred during root canal preparation with different reciprocation systems: Reciproc, WaveOne (M-Wire), and ProDesign R (Shape Memory Technology Wire) at two different working lengths (WLs): 0.0 and 1.0 mm beyond the AF. The AF of 120 root canals in 60 mesial roots of mandibular molars were photographed with stereomicroscope and randomly assigned into four groups: manual, Reciproc (REC), WaveOne (WO), and ProDesign R (PDR); subsequently, they were further subdivided according to the WL (n=15). Teeth were instrumented, coupled to a dual collecting chamber, and then another photograph of each AF was captured. Extrusion was analysed by determining the weight of extruded debris. Each AF diameter was measured in pre- and post-instrumentation images to determine deformation, which was analysed, and afterwards the final format of AFs was classified (circular/oval/deformed). We found no significant differences when analysing each system at different WLs. When considering each WL, REC and WO showed highest extrusion values (P<.05); for AF enlargement, differences were observed only for WO, when it was used beyond the AF; differences were observed among M-Wire groups beyond the AF (P<.05). AF deformation was observed in all groups; PDR showed the lowest AF deformation values at both WLs; M-Wire groups showed 50% strain beyond the AF. Authors concluded that beyond the apical limit, the alloy and taper are important aspects when considering extrusion and deformation.

  14. Preliminary evaluation of beta-spodumene as a fusion reactor structural material

    International Nuclear Information System (INIS)

    Kelsey, P.V. Jr.; Schmunk, R.E.; Henslee, S.P.

    1982-01-01

    Beta-spodumene was investigated as a candidate material for use in fusion reactor environments. Properties which support the use of beta-spodumene include good thermal shock resistance, a very low coefficient of thermal expansion, a low-Z composition which would result in minimum impact on the plasma, and flexibility in fabrication processes. Specimens were irradiated in the Advanced Test Reactor (ATR) to a fluence of 5.3 x 10 22 n/m 2 , E > MeV, and 4.9 x 10 23 n/m 2 thermal fluence in order to obtain a preliminary evaluation of the impact of irradiation on the material. Preliminary data indicate that the mechanical properties of beta-spodumene are little affected by irradiation. Gas production and release have also been investigated. (orig.)

  15. Deformational behaviour of fly-ash based geopolymer concrete at temperatures of up to 150°c

    Directory of Open Access Journals (Sweden)

    Junaid M Talha

    2017-01-01

    Full Text Available The use of Geopolymer Concrete (GP*C has been on the rise over the last few decades owing to its lower carbon emissions as compared to Ordinary Portland Cement Concrete (OPC. Recent research has also established the superior thermal properties of GPC and makes it an ideal construction material for specialized application. However, the deformational behaviour of GPC at elevated temperatures has not fully understood. If GPC is to be used as a main stream construction material for specialized applications, the exact deformational behaviour of the material under thermal loading needs to be investigated. This paper looks into the deformational characteristics of GPC (with natural crushed siliceous aggregates when dry heated up to 150°C at near zero loading. The deformations recorded using a clip-on extensometer are used to determine the strains developed in the GPC samples due to thermal loads. Coefficient of thermal expansion (CTE for the tested GPC samples was found and was comparable to OPC concrete at the tested temperatures. Between ambient (20°C and 80°C the CTE for GPC was determined to be between 10.3-10.9x10−6mm/mm/°C which is similar to OPC concretes. CTE for temperatures between 80°C and 150°C was determined to be 9.3-10.0x10−6 mm/mm/°C. First heating cycles resulted in much lower CTE which may be due to the presence of evaporable water in the samples. Like OPC, GPC is a non-homogeneous material and the variation in the materials between samples account for the slight variation in the CTE values determined.

  16. g-factors in deformed nuclei: Annual report, September 1, 1983-August 31, 1984

    International Nuclear Information System (INIS)

    Krane, K.S.

    1984-01-01

    This report describes work performed for the period September 1, 1983 to August 31, 1984 under the contract DE-AT06-83ER40109, /open quotes/g-Factors in Deformed Nuclei./close quotes/ The literature survey has been completed and the first stage of the raw data analysis has been accomplished. A preliminary data summary prepared for publication is attached

  17. Investigation on Insar Time Series Deformation Model Considering Rheological Parameters for Soft Clay Subgrade Monitoring

    Science.gov (United States)

    Xing, X.; Yuan, Z.; Chen, L. F.; Yu, X. Y.; Xiao, L.

    2018-04-01

    The stability control is one of the major technical difficulties in the field of highway subgrade construction engineering. Building deformation model is a crucial step for InSAR time series deformation monitoring. Most of the InSAR deformation models for deformation monitoring are pure empirical mathematical models, without considering the physical mechanism of the monitored object. In this study, we take rheology into consideration, inducing rheological parameters into traditional InSAR deformation models. To assess the feasibility and accuracy for our new model, both simulation and real deformation data over Lungui highway (a typical highway built on soft clay subgrade in Guangdong province, China) are investigated with TerraSAR-X satellite imagery. In order to solve the unknows of the non-linear rheological model, three algorithms: Gauss-Newton (GN), Levenberg-Marquarat (LM), and Genetic Algorithm (GA), are utilized and compared to estimate the unknown parameters. Considering both the calculation efficiency and accuracy, GA is chosen as the final choice for the new model in our case study. Preliminary real data experiment is conducted with use of 17 TerraSAR-X Stripmap images (with a 3-m resolution). With the new deformation model and GA aforementioned, the unknown rheological parameters over all the high coherence points are obtained and the LOS deformation (the low-pass component) sequences are generated.

  18. A Preliminary Investigation of the Effect of Ocean Thermal Energy Conversion (OTEC Effluent Discharge Options on Global OTEC Resources

    Directory of Open Access Journals (Sweden)

    Gérard Nihous

    2018-03-01

    Full Text Available A simple algorithm previously used to evaluate steady-state global Ocean Thermal Energy Conversion (OTEC resources is extended to probe the effect of various effluent discharge methodologies. It is found that separate evaporator and condenser discharges potentially increase OTEC net power limits by about 60% over a comparable mixed discharge scenario. This stems from a relatively less severe degradation of the thermal resource at given OTEC seawater flow rates, which corresponds to a smaller heat input into the ocean. Next, the most practical case of a mixed discharge into the mixed layer is found to correspond to only 80% of the so-called baseline case (mixed discharge at a water depth of initial neutral buoyancy. In general, locating effluent discharges at initial neutral-buoyancy depths appears to be nearly optimal in terms of OTEC net power production limits. The depth selected for the OTEC condenser effluent discharge, however, has by far the greatest impact. Clearly, these results are preliminary and should be investigated in more complex ocean general circulation models.

  19. Preliminary experiments on wastes degradation by thermal plasma

    International Nuclear Information System (INIS)

    Cota S, G.; Pacheco S, J.; Segovia R, A.; Pena E, R.; Merlo S, L.

    1996-01-01

    This work presents the fundamental aspects involved in the installation and start up of an experimental equipment for the hazardous wastes degradation using the thermal plasma technology. It is mentioned about the form in which the thermal plasma is generated and the characteristics that its make to be an appropriate technology for the hazardous wastes degradation. Just as the installed structures for to realize the experiments and results of the first studies on degradation, using nylon as problem sample. (Author)

  20. Filament networks attached to membranes: cytoskeletal pressure and local bilayer deformation

    International Nuclear Information System (INIS)

    Auth, Thorsten; Safran, S A; Gov, Nir S

    2007-01-01

    Several cell types, among them red blood cells, have a cortical, two-dimensional (2D) network of filaments sparsely attached to their lipid bilayer. In many mammalian cells, this 2D polymer network is connected to an underlying 3D, more rigid cytoskeleton. In this paper, we consider the pressure exerted by the thermally fluctuating, cortical network of filaments on the bilayer and predict the bilayer deformations that are induced by this pressure. We treat the filaments as flexible polymers and calculate the pressure that a network of such linear chains exerts on the bilayer; we then minimize the bilayer shape in order to predict the resulting local deformations. We compare our predictions with membrane deformations observed in electron micrographs of red blood cells. The polymer pressure along with the resulting membrane deformation can lead to compartmentalization, regulate in-plane diffusion and may influence protein sorting as well as transmit signals to the polymerization of the underlying 3D cytoskeleton

  1. SU-F-P-54: Guidelines to Check Image Registration QA of a Clinical Deformation Registration Software: A Single Institution Preliminary Study

    Energy Technology Data Exchange (ETDEWEB)

    Gill, G; Souri, S; Rea, A; Chen, Y; Antone, J; Qian, X; Riegel, A; Taylor, P; Marrero, M; Diaz, F; Cao, Y; Jamshidi, A; Klein, E [Northwell Health, Lake Success, NY (United States); Barley, S; Sorell, V; Karangelis, G [Oncology Systems Limited, Longbow Close, Shrewsbury SY1 3GZ (United Kingdom); Button, T [Stony Brook University Hospital, Stony Brook, NY (United States)

    2016-06-15

    Purpose: The objective of this study is to verify and analyze the accuracy of a clinical deformable image registration (DIR) software. Methods: To test clinical DIR software qualitatively and quantitatively, we focused on lung radiotherapy and analyzed a single (Lung) patient CT scan. Artificial anatomical changes were applied to account for daily variations during the course of treatment including the planning target volume (PTV) and organs at risk (OAR). The primary CT (pCT) and the structure set (pST) was deformed with commercial tool (ImSimQA-Oncology Systems Limited) and after artificial deformation (dCT and dST) sent to another commercial tool (VelocityAI-Varian Medical Systems). In Velocity, the deformed CT and structures (dCT and dST) were inversely deformed back to original primary CT (dbpCT and dbpST). We compared the dbpST and pST structure sets using similarity metrics. Furthermore, a binary deformation field vector (BDF) was created and sent to ImSimQA software for comparison with known “ground truth” deformation vector fields (DVF). Results: An image similarity comparison was made by using “ground truth” DVF and “deformed output” BDF with an output of normalized “cross correlation (CC)” and “mutual information (MI)” in ImSimQA software. Results for the lung case were MI=0.66 and CC=0.99. The artificial structure deformation in both pST and dbpST was analyzed using DICE coefficient, mean distance to conformity (MDC) and deformation field error volume histogram (DFEVH) by comparing them before and after inverse deformation. We have noticed inadequate structure match for CTV, ITV and PTV due to close proximity of heart and overall affected by lung expansion. Conclusion: We have seen similarity between pCT and dbpCT but not so well between pST and dbpST, because of inadequate structure deformation in clinical DIR system. This system based quality assurance test will prepare us for adopting the guidelines of upcoming AAPM task group 132

  2. SU-F-P-54: Guidelines to Check Image Registration QA of a Clinical Deformation Registration Software: A Single Institution Preliminary Study

    International Nuclear Information System (INIS)

    Gill, G; Souri, S; Rea, A; Chen, Y; Antone, J; Qian, X; Riegel, A; Taylor, P; Marrero, M; Diaz, F; Cao, Y; Jamshidi, A; Klein, E; Barley, S; Sorell, V; Karangelis, G; Button, T

    2016-01-01

    Purpose: The objective of this study is to verify and analyze the accuracy of a clinical deformable image registration (DIR) software. Methods: To test clinical DIR software qualitatively and quantitatively, we focused on lung radiotherapy and analyzed a single (Lung) patient CT scan. Artificial anatomical changes were applied to account for daily variations during the course of treatment including the planning target volume (PTV) and organs at risk (OAR). The primary CT (pCT) and the structure set (pST) was deformed with commercial tool (ImSimQA-Oncology Systems Limited) and after artificial deformation (dCT and dST) sent to another commercial tool (VelocityAI-Varian Medical Systems). In Velocity, the deformed CT and structures (dCT and dST) were inversely deformed back to original primary CT (dbpCT and dbpST). We compared the dbpST and pST structure sets using similarity metrics. Furthermore, a binary deformation field vector (BDF) was created and sent to ImSimQA software for comparison with known “ground truth” deformation vector fields (DVF). Results: An image similarity comparison was made by using “ground truth” DVF and “deformed output” BDF with an output of normalized “cross correlation (CC)” and “mutual information (MI)” in ImSimQA software. Results for the lung case were MI=0.66 and CC=0.99. The artificial structure deformation in both pST and dbpST was analyzed using DICE coefficient, mean distance to conformity (MDC) and deformation field error volume histogram (DFEVH) by comparing them before and after inverse deformation. We have noticed inadequate structure match for CTV, ITV and PTV due to close proximity of heart and overall affected by lung expansion. Conclusion: We have seen similarity between pCT and dbpCT but not so well between pST and dbpST, because of inadequate structure deformation in clinical DIR system. This system based quality assurance test will prepare us for adopting the guidelines of upcoming AAPM task group 132

  3. Preliminary results on the non-thermal effects of 200-350 GHz radiation on the growth rate of S. cerevisiae cells in microcolonies

    Science.gov (United States)

    Hadjiloucas, S.; Chahal, M. S.; Bowen, J. W.

    2002-11-01

    We report preliminary results from studies of biological effects induced by non-thermal levels of non-ionizing electromagnetic radiation. Exponentially growing Saccharomyces cerevisiae yeast cells grown on dry media were exposed to electromagnetic fields in the 200-350 GHz frequency range at low power density to observe possible non-thermal effects on the microcolony growth. Exposure to the electromagnetic field was conducted over 2.5 h. The data from exposure and control experiments were grouped into either large-, medium- or small-sized microcolonies to assist in the accurate assessment of growth. The three groups showed significant differences in growth between exposed and control microcolonies. A statistically significant enhanced growth rate was observed at 341 GHz. Growth rate was assessed every 30 min via time-lapse photography. Possible interaction mechanisms are discussed, taking into account Frohlich's hypothesis.

  4. Preliminary results on the non-thermal effects of 200-350 GHz radiation on the growth rate of S. cerevisiae cells in microcolonies

    Energy Technology Data Exchange (ETDEWEB)

    Hadjiloucas, S; Chahal, M S; Bowen, J W [Department of Cybernetics, University of Reading, Whiteknights, RG6 6AY, Berkshire (United Kingdom)

    2002-11-07

    We report preliminary results from studies of biological effects induced by non-thermal levels of non-ionizing electromagnetic radiation. Exponentially growing Saccharomyces cerevisiae yeast cells grown on dry media were exposed to electromagnetic fields in the 200-350 GHz frequency range at low power density to observe possible non-thermal effects on the microcolony growth. Exposure to the electromagnetic field was conducted over 2.5 h. The data from exposure and control experiments were grouped into either large-, medium- or small-sized microcolonies to assist in the accurate assessment of growth. The three groups showed significant differences in growth between exposed and control microcolonies. A statistically significant enhanced growth rate was observed at 341 GHz. Growth rate was assessed every 30 min via time-lapse photography. Possible interaction mechanisms are discussed, taking into account Frohlich's hypothesis.

  5. Analysis of temperature profiles and the mechanism of silicon substrate plastic deformation under epitaxial growth

    International Nuclear Information System (INIS)

    Mirkurbanov, H.A.; Sazhnev, S.V.; Timofeev, V.N.

    2004-01-01

    Full text: Thermal treatment of silicon wafers holds one of the major place in the manufacturing of semi-conductor devices. Thermal treatment includes wafer annealing, thermal oxidation, epitaxial growing etc. Quality of wafers in the high-temperature processes (900-1200 deg C) is estimated by the density of structural defects, including areas of plastic deformation, which are shown as the slip lines appearance. Such areas amount to 50-60 % of total wafer surface. The plastic deformation is caused by the thermal stresses. Experimental and theoretical researches allowed to determine thermal balance and to construct a temperature profiles throughout the plate surface. Thermal stresses are caused by temperature drop along the radius of a wafer and at the basic peripheral ring. The threshold temperature drop between center f a wafer and its peripherals (ΔT) for slip lines appearance, amounts to 15-17 deg. C. At the operating temperature of 900-1200 deg. C and ΔT>20 deg. C, the stresses reach the silicon yield point. According to the results of the researches of structure and stress profiles in a wafer, the mechanism of slip lines formation has been constructed. A source of dislocations is the rear broken layer of thickness 8-10 microns, formed after polishing. The micro-fissures with a density 10 5 -10 6 cm -2 are the sources of dislocations. Dislocations move on a surface of a wafer into a slip plane (111). On a wafer surface with orientation (111) it is possible to allocate zones where the tangential stress vector is most favorably directed with respect to a slip plane leaving on a surface, i.e. the shift stresses are maximal in the slip plane. The way to eliminate plastic deformation is to lower the temperature drop to a level of <15 deg. C and elimination of the broken layer in wafer

  6. Thermal expansion coefficient determination of polylactic acid using digital image correlation

    Directory of Open Access Journals (Sweden)

    Botean Adrian - Ioan

    2018-01-01

    Full Text Available This paper aims determining the linear thermal expansion coefficient (CTE of polylactic acid (PLA using an optical method for measuring deformations called digital image correlation method (DIC. Because PLA is often used in making many pieces with 3D printing technology, it is opportune to know this coefficient to obtain a higher degree of precision in the construction of parts and to monitor deformations when these parts are subjected to a thermal gradient. Are used two PLA discs with 20 and 40% degree of filling. In parallel with this approach was determined the linear thermal expansion coefficient (CTE for the copper cylinder on the surface of which are placed the two discs of PLA.

  7. Thermal expansion coefficient determination of polylactic acid using digital image correlation

    Science.gov (United States)

    Botean, Adrian-Ioan

    2018-02-01

    This paper aims determining the linear thermal expansion coefficient (CTE) of polylactic acid (PLA) using an optical method for measuring deformations called digital image correlation method (DIC). Because PLA is often used in making many pieces with 3D printing technology, it is opportune to know this coefficient to obtain a higher degree of precision in the construction of parts and to monitor deformations when these parts are subjected to a thermal gradient. Are used two PLA discs with 20 and 40% degree of filling. In parallel with this approach was determined the linear thermal expansion coefficient (CTE) for the copper cylinder on the surface of which are placed the two discs of PLA.

  8. Features of energy impact on a billet material when cutting with outstripping plastic deformation

    Directory of Open Access Journals (Sweden)

    V. M. Yaroslavtsev

    2014-01-01

    cases. At the same time, when cutting with OPD, a part of the work spent on plastic deformations, is preliminary carried out by an additional mechanical energy source, i.e. by the device for superficial plastic deformation of material. As a result the cutting tool makes only the rest of the work that can facilitate to decrease of cutting force and temperature. The cutting force and temperature define a stress of machining process. Reduction of these parameters when cutting with OPD allows us to rise the resistance period of the cutting tool (up to 2–6 times and the workforce productivity (up to 1,1–1,6 times depending on physic-mechanical properties of processed material.However, the maximum efficiency of additional mechanical influence is reached only when there is the optimum relationship between the specific energy of superficial material deformation of a cut-off layer and chip formation process while cutting. Experimental data show that at small specific loads of preliminary material deformation an increase of these loads leads to the increase of a part of additional energy during the cut-off layer removal that enables efficiency increase of cutting process with OPD. At the same time, with increasing extent of preliminary plastic deformation of removable material the microhardness of a cut-off layer increases. It has a negative impact on the interaction conditions of tool contact surfaces with a billet material, increases the stress of cutting process, leads to decrease of technical-andeconomic indicators of machining. As a result at the raised specific loads of preliminary deformation negative factors become prevailing and cause, at first, decreasing process efficiency. The further increase of deformation work leads to a negative effect of additional OPD energy influence.Thus, an influence efficiency of additional external energies in the combined methods of machining depends on many factors, and the result of such impact on the billet can change over a wide

  9. Experimental energetic balance associated to the deformation of an aluminum multicrystal and monocrystal sheet

    Energy Technology Data Exchange (ETDEWEB)

    Louche, H.; Tabourot, L. [LMecA ESIA, Domaine Univ., Annecy (France)

    2004-07-01

    This paper presents a method to estimate the stored energy during the tensile deformation of an aluminum multicrystal and polycrystal sheet sample. The method is based on thermo mechanical macroscopic fields analysis, like strains and temperature, obtained by a visible and an infrared cameras. Preliminary experimental results are presented. On an Al multicrystal sheet, heterogeneous thermo mechanical fields associated to the localized movement of dislocations at a microscopic scale are presented. Furthermore, the energetic balance established during the tensile deformation of an Al polycristal show a decreasing ratio of stored energy on anelastic energy and a non constant fraction of total work converted into heat. (orig.)

  10. Debris extrusion and foraminal deformation produced by reciprocating instruments made of thermally treated NiTi wires

    Directory of Open Access Journals (Sweden)

    Myrna Maria Arcanjo Frota

    2018-01-01

    Full Text Available Abstract Objective To evaluate the amount of apically extruded debris, percentage of foraminal enlargement and apical foramen (AF deformation that occurred during root canal preparation with different reciprocation systems: Reciproc, WaveOne (M-Wire, and ProDesign R (Shape Memory Technology Wire at two different working lengths (WLs: 0.0 and 1.0 mm beyond the AF. Material and methods The AF of 120 root canals in 60 mesial roots of mandibular molars were photographed with stereomicroscope and randomly assigned into four groups: manual, Reciproc (REC, WaveOne (WO, and ProDesign R (PDR; subsequently, they were further subdivided according to the WL (n=15. Teeth were instrumented, coupled to a dual collecting chamber, and then another photograph of each AF was captured. Extrusion was analysed by determining the weight of extruded debris. Each AF diameter was measured in pre- and post-instrumentation images to determine deformation, which was analysed, and afterwards the final format of AFs was classified (circular/oval/deformed. Results We found no significant differences when analysing each system at different WLs. When considering each WL, REC and WO showed highest extrusion values (P<.05; for AF enlargement, differences were observed only for WO, when it was used beyond the AF; differences were observed among M-Wire groups beyond the AF (P<.05. AF deformation was observed in all groups; PDR showed the lowest AF deformation values at both WLs; M-Wire groups showed 50% strain beyond the AF. Conclusion Authors concluded that beyond the apical limit, the alloy and taper are important aspects when considering extrusion and deformation.

  11. Effect of acoustic softening on the thermal-mechanical process of ultrasonic welding.

    Science.gov (United States)

    Chen, Kunkun; Zhang, Yansong; Wang, Hongze

    2017-03-01

    Application of ultrasonic energy can reduce the static stress necessary for plastic deformation of metallic materials to reduce forming load and energy, namely acoustic softening effect (ASE). Ultrasonic welding (USW) is a rapid joining process utilizing ultrasonic energy to form a solid state joint between two or more pieces of metals. Quantitative characterization of ASE and its influence on specimen deformation and heat generation is essential to clarify the thermal-mechanical process of ultrasonic welding. In the present work, experiments were set up to found out mechanical behavior of copper and aluminum under combined effect of compression force and ultrasonic energy. Constitutive model was proposed and numerical implemented in finite element model of ultrasonic welding. Thermal-mechanical analysis was put forward to explore the effect of ultrasonic energy on the welding process quantitatively. Conclusions can be drawn that ASE increases structural deformation significantly, which is beneficial for joint formation. Meanwhile, heat generation from both frictional work and plastic deformation is slightly influenced by ASE. Based on the proposed model, relationship between ultrasonic energy and thermal-mechanical behavior of structure during ultrasonic welding was constructed. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Assessment of stability during gait in patients with spinal deformity-A preliminary analysis using the dynamic stability margin.

    Science.gov (United States)

    Simon, Anne-Laure; Lugade, Vipul; Bernhardt, Kathie; Larson, A Noelle; Kaufman, Kenton

    2017-06-01

    Daily living activities are dynamic, requiring spinal motion through space. Current assessment of spinal deformities is based on static measurements from full-spine standing radiographs. Tools to assess dynamic stability during gait might be useful to enhance the standard evaluation. The aim of this study was to evaluate gait dynamic imbalance in patients with spinal deformity using the dynamic stability margin (DSM). Twelve normal subjects and 17 patients with spinal deformity were prospectively recruited. A kinematic 3D gait analysis was performed for the control group (CG) and the spinal deformity group (SDG). The DSM (distance between the extrapolated center of mass and the base of support) and time-distance parameters were calculated for the right and left side during gait. The relationship between DSM and step length was assessed using three variables: gait stability, symmetry, and consistency. Variables' accuracy was validated by a discriminant analysis. Patients with spinal deformity exhibited gait instability according to the DSM (0.25m versus 0.31m) with decreased velocity (1.1ms -1 versus 1.3ms -1 ) and decreased step length (0.32m versus 0.38m). According to the discriminant analysis, gait stability was the more accurate variable (area under the curve AUC=0.98) followed by gait symmetry and consistency. However, gait consistency showed 100% of specificity, sensitivity, and accuracy of precision. The DSM showed that patients with spinal malalignment exhibit decreased gait stability, symmetry, and consistency besides gait time-distance parameter changes. Additional work is required to determine how to apply the DSM for preoperative and postoperative spinal deformity management. Copyright © 2017. Published by Elsevier B.V.

  13. Preliminary analysis of geothermal aspects of Brazilian thermal spring

    International Nuclear Information System (INIS)

    Hurter, S.J.; Hamza, V.M.

    1982-01-01

    Information on more than 400 geothermal springs in Brazil has been assembled. On the basis of the data colected the temperatures at the maximum depths of circulation of spring waters are calculated using the quality of silica dissolved in water. For some thermal springs temperatures are calculated on the basis of silica determination carrried out by us. Applying linear relations between silica temperature and geothermal flux the average depths of water circulation in the Parana Basin and the Brazilian folded belts surrounding the San Francisco craton are calculated. The radioactivity of the water, derived mainly from the dissolved radon can be correlated with the temperature of the spring. An inverse correlation, as was observed for thermal springs of Pocos de Caldas, can be used to calculate the ascent velocity of thermal waters, where as, a positive correlations could be interpreted as due to the mixing of thermal with surface waters. (Author) [pt

  14. Characterization of local plastic instability during deformation of D9 clad tubes for fast breeder nuclear fuel by infrared thermography

    International Nuclear Information System (INIS)

    Kapoor, K.; Somasekhar Reddy, K.; Ramana Rao, A.V.

    2009-01-01

    Plastic instability is a condition occurring ahead of ductile fracture in materials subjected to deformation. This condition is a warning before the final failure occurring by ductile fracture. This condition manifests during necking in tensile deformation and crack propagation during plastic deformation. Early detection of such a condition can prevent permanent damage. In the present case, a novel approach by use of infrared thermography is proposed for characterization of local plastic instability during deformation of D9 clad tube material. Infrared thermal imaging was used for acquiring data during deformation by plug drawing, pilgering and uniaxial tension tests. The local plastic instability due to propagation of defects was monitored by use of Taylor-Quinney coefficient (β). Where, the Taylor-Quinney coefficient is defined as the ratio of plastic work converted into heat, which was evaluated by using thermal imaging data. In our study, an analysis of the heat generated during the process of plastic deformation was measured thereby correlating the abnormal temperature variations with the defects appearing in the material. In our study, an analysis of the heat generated during the process of plastic deformation was measured thereby correlating the abnormal temperature variations with the defects appearing in the material

  15. A two-dimensional deformable phantom for quantitatively verifying deformation algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, Neil; Chuang, Cynthia; Pouliot, Jean [Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143-1708 (United States)

    2011-08-15

    Purpose: The incorporation of deformable image registration into the treatment planning process is rapidly advancing. For this reason, the methods used to verify the underlying deformation algorithms must evolve equally fast. This manuscript proposes a two-dimensional deformable phantom, which can objectively verify the accuracy of deformation algorithms, as the next step for improving these techniques. Methods: The phantom represents a single plane of the anatomy for a head and neck patient. Inflation of a balloon catheter inside the phantom simulates tumor growth. CT and camera images of the phantom are acquired before and after its deformation. Nonradiopaque markers reside on the surface of the deformable anatomy and are visible through an acrylic plate, which enables an optical camera to measure their positions; thus, establishing the ground-truth deformation. This measured deformation is directly compared to the predictions of deformation algorithms, using several similarity metrics. The ratio of the number of points with more than a 3 mm deformation error over the number that are deformed by more than 3 mm is used for an error metric to evaluate algorithm accuracy. Results: An optical method of characterizing deformation has been successfully demonstrated. For the tests of this method, the balloon catheter deforms 32 out of the 54 surface markers by more than 3 mm. Different deformation errors result from the different similarity metrics. The most accurate deformation predictions had an error of 75%. Conclusions: The results presented here demonstrate the utility of the phantom for objectively verifying deformation algorithms and determining which is the most accurate. They also indicate that the phantom would benefit from more electron density heterogeneity. The reduction of the deformable anatomy to a two-dimensional system allows for the use of nonradiopaque markers, which do not influence deformation algorithms. This is the fundamental advantage of this

  16. Atomistic simulation study of deformation twinning of nanocrystalline body-centered cubic Mo

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Xiaofeng [The College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu (China); Li, Dan, E-mail: txf8378@163.com [The College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu (China); Yu, You [College of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu (China); You, Zhen Jiang [Australian School of Petroleum, University of Adelaide, SA 5005 (Australia); Li, Tongye [The National Key Laboratory of Nuclear Fuel and Materials, Nuclear Power Institute of China, Chengdu (China); Ge, Liangquan [The College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu (China)

    2017-04-06

    Deformation twinning of nanocrystalline body-centered cubic Mo was studied using molecular dynamics simulations, and the effects of grain sizes and temperatures on the deformation were evaluated. With small grain size, grain rotation accompanying grain growth was found to play important role in nanocrystalline Mo during tensile deformation. Additionally, grain rotation and the deformation controlled by GB-mediated processes induce to the difficulty of creating crack. Twin was formed by successive emission of twinning partials from grain boundaries in small grain size systems. However, the twin mechanisms of GB splitting and overlapping of two extended dislocations were also found in larger size grain. Twin induced crack tips were observed in our simulation, and this confirmed the results of previous molecular dynamics simulations. At higher temperatures, GB activities can be thermally activated, resulting in suppression of twinning tendency and improvement of ductility of nanocrystalline Mo.

  17. Heat pipe solar receiver with thermal energy storage

    Science.gov (United States)

    Zimmerman, W. F.

    1981-01-01

    An HPSR Stirling engine generator system featuring latent heat thermal energy storge, excellent thermal stability and self regulating, effective thermal transport at low system delta T is described. The system was supported by component technology testing of heat pipes and of thermal storage and energy transport models which define the expected performance of the system. Preliminary and detailed design efforts were completed and manufacturing of HPSR components has begun.

  18. Ultrasonic inspection of steam generator tubing for cracks, wall thinning and cross-sectional deformation

    International Nuclear Information System (INIS)

    Meyer, P.A.; Carodiskey, T.J.

    1988-01-01

    Periodic inspection of steam generator tubing is an important consideration in the efficient operation of a power generating facility. Since the operating life of these generators is finite, failures will occur. Due to the chemistry of the environment, thermal cycling, and other factors, flaws may develop that can cause rapid deterioration of the tubing while the overall performance of the unit may appear normal. In earlier presentation, the authors presented an ultrasonic bore-side array transducer which can be used with a conventional flaw detector instrument for the location of circumferential crack type defects on the outside tube surface. since that time, much additional experience has been gained on the performance of these probes. Probe performance has been characterized using fatigue crack samples and these results are reviewed. Probes have also been developed having 16 elements for use in larger diameter (25 mm) tubes. The bore-side array concept has been expanded to normal incidence tube well inspection allowing simultaneous wall thickness and eccentricity measurement which is very useful in the assessment of tube wastage and deformation. Preliminary data obtained in this area is presented

  19. Study of low energy thermal constraints for a copper-plated niobium structure carried out by thermal projection

    International Nuclear Information System (INIS)

    Gassot, H.; Durante, M.; Thiebault, A.; Vernay, E.

    1999-06-01

    In the framework of T.T.F. (Tesla Test Facility), the international collaboration on research and development of superconducting cavities, a study of a new method of manufacturing cavities was launched, which consists in deposing a metal (copper) or an alloy by thermal projection on niobium cavities in order to stiffen them. Analytical and numerical calculations showed that when cooled this bi-material cavities behave very differently in comparison with classical pure niobium cavities and strong thermal constraints do occur in niobium as well as in copper. These strong constraints may have important consequences upon the functioning of superconducting cavities. In addition these constraints may induce in time cracks in materials and interfaces. In this paper an experiment for measuring constraints at the temperature of cavity operation, i.e., at the liquid helium temperature, is proposed in order to compare the measured constraints with the calculated constraints. The sample studied has a cylindrical shape, rather representative for the geometrical shape of cavities, but easier to handle than a prototype cavity. The experimental approach consists in carrying out two deformation measurements. The first one, is done on single material sample (niobium and copper) to establish the laws of compensation of the constraint gauges as a function of temperature. The other measurement establishes the global deformations of a bi-metallic tube (Nb-Cu) when the interior surface (niobium) and the external surface (porous copper) of the tube are cooled. From these deformation data the thermal constraints of the bi-metallic tube at low temperature have been derived. The implementation of the entire setup of the methods of measuring the constraints at low temperature constitutes a new development in the field of superconducting cavities. The experiments have also indicated certain further developments which should be achieved if the plastic deformations induced by the freezing regime

  20. Deformation Cycling of a Ti - Ni Alloy with Superelasticity Effect Applied in Cardiology

    Science.gov (United States)

    Kaputkin, D. E.; Morozova, T. V.

    2014-07-01

    The study concerns the effect of the conditions and of the force of loading experienced by an implanted device from a Ti - Ni alloy during its transfer to the working zone, for example, in endoscopic implantation into the coronary sinus of the greater vena cava of heart. It is shown that preliminary deformation cycling (10 - 15 cycles) stabilizes the set of mechanical properties of the alloy.

  1. InSAR Analysis of Post-Seismic Deformation Following the 2013 Mw 7.7 Balochistan, Pakistan Earthquake

    Science.gov (United States)

    Peterson, K.; Barnhart, W. D.

    2017-12-01

    On September 24th, 2013, a Mw 7.7 earthquake ruptured a 200 km portion of the Hoshab fault, a reverse fault in the Makran accretionary prism of southern Pakistan. This earthquake is notable because it ruptured a reverse fault with a predominantly strike-slip sense of displacement, and it ruptured a mechanically weak accretionary prism. Here, we present initial analysis of ongoing post-seismic deformation imaged with the Sentinel-1 interferometric synthetic aperture radar (InSAR) mission with the goals of a) determining the dominant post-seismic deformation processes active, b) characterizing the rigidity and rheological structure of a flat-slab subduction zone, and c) elucidating whether post-seismic deformation may account for or exacerbate the 4-6 m fault convergence deficit left by the 2013 earthquake. We first present InSAR time series analysis of the post-seismic transient derived from ongoing Sentinel-1 SAR acquisitions, including a comparison of atmosphere-corrected and uncorrected time series. Interferograms spanning December 2014 to the present reveal an ongoing post-seismic deformation transient in the region surrounding the Hoshab fault. Additionally, fault creep signals on and adjacent to the Hoshab fault are present. Second, we present a suite of forward models that explore the potential contributions of viscoelastic relaxation and frictional afterslip to the recorded displacement signal. These models, conducted using the semi-analytical solutions of RELAX and compared to InSAR line-of-sight time series displacements, explore a range of candidate rheological descriptions of the Makran subduction zone that are designed to probe the rheological structure of a region where current knowledge of the subsurface geology is highly limited. Our preliminary results suggest that post-seismic displacements arise from a combination of viscoelastic deformation and frictional afterslip, as opposed to one single mechanism. Additionally, our preliminary results suggest

  2. Stress relaxation under cyclic electron irradiation

    International Nuclear Information System (INIS)

    Bystrov, L.N.; Reznitskij, M.E.

    1990-01-01

    The kinetics of deformation process in a relaxating sample under 2 MeV electron cyclic irradiation was studied experimentally. The Al-Mg alloys with controllable and different (in dislocation density precipitate presence and their character) structure were used in experiments. It was established that after the beam was switched on the deformation rate increased sharply and then, during prolonged irradiation, in a gradual manner. After the switching-off the relaxation rate decreases by jumps up to values close to extrapolated rates of pre-radiation relaxation. The exhibition of these effects with radiation switching-off and switchin-on is dependent on the initial rate of thermal relaxation, the test temperature, the preliminary cold deformation and the dominating deformation dislocation mechanism. The preliminary cold deformation and test temperature elevation slightly decrease the effect of instantaneous relaxation acceleration with the irradiation switch-on. 17 refs., 5 figs

  3. Response of mechanical properties of glasses to their chemical, thermal and mechanical histories

    DEFF Research Database (Denmark)

    Yue, Yuanzheng

    , surface, thermal history or excess entropy of the final glass state. Here I review recent progresses in understanding of the responses of mechanical properties of oxide glasses to the compositional variation, thermal history and mechanical deformation. The tensile strength, elastic modulus and hardness...... of glass fibers are dependent on the thermal history (measured as fictive temperature), tension, chemical composition and redox state. However, the fictive temperature affects the hardness of bulk glass in a complicated manner, i.e., the effect does not exhibit a clear regularity in the range...... and micro-cracks occurring during indentation of a glass is discussed briefly. Finally I describe the future perspectives and challenges in understanding responses of mechanical properties of oxide glasses to compositional variation, thermal history and mechanical deformation....

  4. Elastic-plastic cyclic deformation of the TEXTOR 94 modified liner under conditions of heating and plasma disruption

    International Nuclear Information System (INIS)

    Bohn, F.H.; Czymek, G.; Giesen, B.; Bondarchuk, E.; Doinikov, N.; Kozhukhovskaja, N.; Panin, A.

    2001-01-01

    The present liner of the TEXTOR 94 tokamak installed inside the vacuum vessel represents the thin toroidal shell that is rested on the vessel inner surface. In order to integrate the dynamic ergodic divertor into the tokamak the liner design has been drastically changed. The 120 deg. sector of the liner shell facing the ergodic coils system is removed and some additional holes in the liner are provisioned. This demands a new liner supporting system allowing for the liner thermal expansion and taking the electromagnetic load occurring in the liner during plasma disruption. The cyclic elasto-plastic deformations of the liner caused by the electromagnetic forces and temperature rise have been studied. It is shown that the local plastic deformations occur in the liner elements after the first heating and electromagnetic loading. The most thermal stresses take place in the reinforcing structures around the holes because of the thermal expansion difference of the inconel shell and the steel reinforcements. These stresses are coupled with the bending stress due to the electromagnetic loading. Subsequent repetitive loading does not lead to any significant increment of the plastic deformation. After the materials' hardening the structure cyclically works mostly in the elastic range

  5. The state of deformation in earthlike self-gravitating objects

    CERN Document Server

    Müller, Wolfgang H

    2016-01-01

    This book presents an in-depth continuum mechanics analysis of the deformation due to self-gravitation in terrestrial objects, such as the inner planets, rocky moons and asteroids. Following a brief history of the problem, modern continuum mechanics tools are presented in order to derive the underlying field equations, both for solid and fluid material models. Various numerical solution techniques are discussed, such as Runge-Kutta integration, series expansion, finite differences, and (adaptive) FE analysis. Analytical solutions for selected special cases, which are worked out in detail, are also included. All of these methods are then applied to the problem, quantitative results are compared, and the pros and cons of the analytical solutions and of all the numerical methods are discussed. The book culminates in a multi-layer model for planet Earth according to the PREM Model (Preliminary Earth Model) and in a viscoelastic analysis of the deformation problem, all from the viewpoint of rational continuum theo...

  6. Preliminary Thermohydraulic Analysis of a New Moderated Reactor Utilizing an LEU-Fuel for Space Nuclear Thermal Propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Seung Hyun; Choi, Jae Young; Venneria, Paolo F.; Jeong, Yong Hoon; Chang, Soon Heung [KAIST, Daejeon (Korea, Republic of)

    2015-10-15

    The Korea Advanced NUclear Thermal Engine Rocket utilizing an LEU fuel (KANUTER-LEU) is a non-proliferative and comparably efficient NTR engine with relatively low thrust levels of 40 - 50 kN for in-space transportation. The small modular engine can expand mission versatility, when flexibly used in a clustered engine arrangement, so that it can perform various scale missions from low-thrust robotic science missions to high-thrust manned missions. In addition, the clustered engine system can enhance engine redundancy and ensuing crew safety as well as the thrust. The propulsion system is an energy conversion system to transform the thermal energy of the reactor into the kinetic energy of the propellant to produce the powers for thrust, propellant feeding and electricity. It is mainly made up of a propellant Feeding System (PFS) comprising a Turbo-Pump Assembly (TPA), a Regenerative Nozzle Assembly (RNA), etc. For this core design study, an expander cycle is assumed to be the propulsion system. The EGS converts the thermal energy of the EHTGR in the idle operation (only 350 kW{sub th} power) to electric power during the electric power mode. This paper presents a preliminary thermohydraulic design analysis to explore the design space for the new reactor and to estimate the referential engine performance. The new non-proliferative NTR engine concept, KANUTER-LEU, is under designing to surmount the nuclear proliferation obstacles on allR and Dactivities and eventual commercialization for future generations. To efficiently implement a heavy LEU fuel for the NTR engine, its reactor design innovatively possesses the key characteristics of the high U density fuel with high heating and H{sub 2} corrosion resistances, the thermal neutron spectrum core and also minimizing non-fission neutron loss, and the compact reactor design with protectively cooling capability. To investigate feasible design space for the moderated EHTGR-LEU and resultant engine performance, the

  7. Solar applications of thermal energy storage. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.; Taylor, L.; DeVries, J.; Heibein, S.

    1979-01-01

    A technology assessment is presented on solar energy systems which use thermal energy storage. The study includes characterization of the current state-of-the-art of thermal energy storage, an assessment of the energy storage needs of solar energy systems, and the synthesis of this information into preliminary design criteria which would form the basis for detailed designs of thermal energy storage. (MHR)

  8. Non-local modelling of cyclic thermal shock damage including parameter estimation

    NARCIS (Netherlands)

    Damhof, F.; Brekelmans, W.A.M.; Geers, M.G.D.

    2011-01-01

    In this paper, rate dependent evolution laws are identified and characterized to model the mechanical (elasticity-based) and thermal damage occurring in coarse grain refractory material subject to cyclic thermal shock. The interacting mechanisms for elastic deformation driven damage induced by

  9. Application of Thermal Network Model to Transient Thermal Analysis of Power Electronic Package Substrate

    Directory of Open Access Journals (Sweden)

    Masaru Ishizuka

    2011-01-01

    Full Text Available In recent years, there is a growing demand to have smaller and lighter electronic circuits which have greater complexity, multifunctionality, and reliability. High-density multichip packaging technology has been used in order to meet these requirements. The higher the density scale is, the larger the power dissipation per unit area becomes. Therefore, in the designing process, it has become very important to carry out the thermal analysis. However, the heat transport model in multichip modules is very complex, and its treatment is tedious and time consuming. This paper describes an application of the thermal network method to the transient thermal analysis of multichip modules and proposes a simple model for the thermal analysis of multichip modules as a preliminary thermal design tool. On the basis of the result of transient thermal analysis, the validity of the thermal network method and the simple thermal analysis model is confirmed.

  10. Deformations of fuel elements under irradiation (Examination of the 2000 C set, investigation of the Cottrell effect)

    International Nuclear Information System (INIS)

    Thome, P.; Allain, C.

    1959-04-01

    The authors report visual and radiographic examinations of cartridges of the 2000 C solution C in order to study the influence of the combustion rate on deformations of these cartridges which spent about a year in an atomic pile. The deformation measurements are interpreted in terms of creep phenomena (Cottrell effect), of surface condition, and buckling. The authors discuss the validity of mechanical tests, the distinction between creep and flow, the deformation of fuel assemblies, the validity of thermal cycle tests, the effects of alloy compositions

  11. Ams Fabric and Deformation of The Jawornik Granitoids In The Zloty Stok - Skrzynka Deformation Zone (sudetes, SW Poland)- Preliminary Interpretations.

    Science.gov (United States)

    Werner, T.; Bialek, D.

    Jawornik granitoids comprise the NE-SW trending sequences of the 1cm up to 1 km thick granitoid veins surrounded by schists and gneisses of the Zloty Stok - Skrzynka deformation zone in Eastern Sudetes (SW Poland). According to conflicting theories granitoids are of magmatic origin or were formed from blastomylonitic rocks that underwent multiphase deformation. AMS studies were performed for the 53 sites lo- calized within granitoid veins and within the surrounding gneisses. AMS foliations for granitoid veins of various thickness as well as for gneisses dip at moderate to steep an- gles to N-NW. AMS lineations in the surrounding gneisses plunge subhorizontally to NE-SW that reflects the regional NE-SW shearing components. Magnetic lineations for sites within wider veins of granitoids plunge at low angles (mostly from S to W) but with more varying trends between sites. Mezoscopic tectonic foliations are record- able only in 50% of sites. They show good correlation with AMS planar fabric on the site scale. The uniformity of AMS fabric on the site scale and high AMS anisotropy within all sites (P of 1.05-1.30, T of 0.3-0.6 on average) suggest syntectonic gener- ation of granitoids. Further interpretations of the AMS and tectonic fabrics will be performed when microtectonic studies and chemical analyses results are available.

  12. System-Level Heat Transfer Analysis, Thermal- Mechanical Cyclic Stress Analysis, and Environmental Fatigue Modeling of a Two-Loop Pressurized Water Reactor. A Preliminary Study

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Subhasish [Argonne National Lab. (ANL), Argonne, IL (United States); Soppet, William [Argonne National Lab. (ANL), Argonne, IL (United States); Majumdar, Saurin [Argonne National Lab. (ANL), Argonne, IL (United States); Natesan, Ken [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-01-03

    This report provides an update on an assessment of environmentally assisted fatigue for light water reactor components under extended service conditions. This report is a deliverable in April 2015 under the work package for environmentally assisted fatigue under DOE's Light Water Reactor Sustainability program. In this report, updates are discussed related to a system level preliminary finite element model of a two-loop pressurized water reactor (PWR). Based on this model, system-level heat transfer analysis and subsequent thermal-mechanical stress analysis were performed for typical design-basis thermal-mechanical fatigue cycles. The in-air fatigue lives of components, such as the hot and cold legs, were estimated on the basis of stress analysis results, ASME in-air fatigue life estimation criteria, and fatigue design curves. Furthermore, environmental correction factors and associated PWR environment fatigue lives for the hot and cold legs were estimated by using estimated stress and strain histories and the approach described in NUREG-6909. The discussed models and results are very preliminary. Further advancement of the discussed model is required for more accurate life prediction of reactor components. This report only presents the work related to finite element modelling activities. However, in between multiple tensile and fatigue tests were conducted. The related experimental results will be presented in the year-end report.

  13. Thermal conductivity at a disordered quantum critical point

    International Nuclear Information System (INIS)

    Hartnoll, Sean A.; Ramirez, David M.; Santos, Jorge E.

    2016-01-01

    Strongly disordered and strongly interacting quantum critical points are difficult to access with conventional field theoretic methods. They are, however, both experimentally important and theoretically interesting. In particular, they are expected to realize universal incoherent transport. Such disordered quantum critical theories have recently been constructed holographically by deforming a CFT by marginally relevant disorder. In this paper we find additional disordered fixed points via relevant disordered deformations of a holographic CFT. Using recently developed methods in holographic transport, we characterize the thermal conductivity in both sets of theories in 1+1 dimensions. The thermal conductivity is found to tend to a constant at low temperatures in one class of fixed points, and to scale as T"0"."3 in the other. Furthermore, in all cases the thermal conductivity exhibits discrete scale invariance, with logarithmic in temperature oscillations superimposed on the low temperature scaling behavior. At no point do we use the replica trick.

  14. Boundary-integral equation formulation for time-dependent inelastic deformation in metals

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, V; Mukherjee, S

    1977-01-01

    The mathematical structure of various constitutive relations proposed in recent years for representing time-dependent inelastic deformation behavior of metals at elevated temperatues has certain features which permit a simple formulation of the three-dimensional inelasticity problem in terms of real time rates. A direct formulation of the boundary-integral equation method in terms of rates is discussed for the analysis of time-dependent inelastic deformation of arbitrarily shaped three-dimensional metallic bodies subjected to arbitrary mechanical and thermal loading histories and obeying constitutive relations of the kind mentioned above. The formulation is based on the assumption of infinitesimal deformations. Several illustrative examples involving creep of thick-walled spheres, long thick-walled cylinders, and rotating discs are discussed. The implementation of the method appears to be far easier than analogous BIE formulations that have been suggested for elastoplastic problems.

  15. Radiation effects on time-dependent deformation: Creep and growth

    International Nuclear Information System (INIS)

    Simonen, E.P.

    1989-03-01

    Observations of irradiation creep strain as well as irradiation growth strain and related microstructures are reviewed and compared to mechanisms for radiation effects on time-dependent deformation. Composition, microstructure, stress and temperature affect irradiation creep less than thermal creep. Irradiation creep rates can often dominate thermal creep rates, particularly at low temperatures and low stresses. Irradiation creep mechanisms are classified in two general categories: (1) stress-induced preferential absorption and (2) climb-glide. In the former, creep results from dislocation climb, whereas in the latter, creep results from dislocation glide. The effects of irradiation creep on failure modes in nuclear environments are discussed. 53 refs., 18 figs., 1 tab

  16. Confined Water in Layered Silicates: The Origin of Anomalous Thermal Expansion Behavior in Calcium-Silicate-Hydrates

    International Nuclear Information System (INIS)

    Krishnan, N. M. Anoop; Wang, Bu; Falzone, Gabriel; Le Pape, Yann; Neithalath, Narayanan

    2016-01-01

    Water, under conditions of nanoscale confinement, exhibits anomalous dynamics, and enhanced thermal deformations, which may be further enhanced when such water is in contact with hydrophilic surfaces. Such heightened thermal deformations of water could control the volume stability of hydrated materials containing nanoconfined structural water. Understanding and predicting the thermal deformation coefficient (TDC, often referred to as the CTE, coefficient of thermal expansion), which represents volume changes induced in materials under conditions of changing temperature, is of critical importance for hydrated solids including: hydrogels, biological tissues, and calcium silicate hydrates, as changes in their volume can result in stress development, and cracking. By pioneering atomistic simulations, we examine the physical origin of thermal expansion in calcium-silicate-hydrates (C–S–H), the binding agent in concrete that is formed by the reaction of cement with water. We report that the TDC of C–S–H shows a sudden increase when the CaO/SiO_2 (molar ratio; abbreviated as Ca/Si) exceeds 1.5. This anomalous behavior arises from a notable increase in the confinement of water contained in the C–S–H’s nanostructure. We identify that confinement is dictated by the topology of the C–S–H’s atomic network. Altogether, the results suggest that thermal deformations of hydrated silicates can be altered by inducing compositional changes, which in turn alter the atomic topology and the resultant volume stability of the solids.

  17. Confined Water in Layered Silicates: The Origin of Anomalous Thermal Expansion Behavior in Calcium-Silicate-Hydrates.

    Science.gov (United States)

    Krishnan, N M Anoop; Wang, Bu; Falzone, Gabriel; Le Pape, Yann; Neithalath, Narayanan; Pilon, Laurent; Bauchy, Mathieu; Sant, Gaurav

    2016-12-28

    Water, under conditions of nanoscale confinement, exhibits anomalous dynamics, and enhanced thermal deformations, which may be further enhanced when such water is in contact with hydrophilic surfaces. Such heightened thermal deformations of water could control the volume stability of hydrated materials containing nanoconfined structural water. Understanding and predicting the thermal deformation coefficient (TDC, often referred to as the CTE, coefficient of thermal expansion), which represents volume changes induced in materials under conditions of changing temperature, is of critical importance for hydrated solids including: hydrogels, biological tissues, and calcium silicate hydrates, as changes in their volume can result in stress development, and cracking. By pioneering atomistic simulations, we examine the physical origin of thermal expansion in calcium-silicate-hydrates (C-S-H), the binding agent in concrete that is formed by the reaction of cement with water. We report that the TDC of C-S-H shows a sudden increase when the CaO/SiO 2 (molar ratio; abbreviated as Ca/Si) exceeds 1.5. This anomalous behavior arises from a notable increase in the confinement of water contained in the C-S-H's nanostructure. We identify that confinement is dictated by the topology of the C-S-H's atomic network. Taken together, the results suggest that thermal deformations of hydrated silicates can be altered by inducing compositional changes, which in turn alter the atomic topology and the resultant volume stability of the solids.

  18. Preliminary Geological Map of the Fortuna Tessera (V-2) Quadrangle, Venus

    Science.gov (United States)

    Ivanov, M. A.; Head, J. W.

    2009-01-01

    The Fortuna Tessera quadrangle (50-75 N, 0-60 E) is a large region of tessera [1] that includes the major portion of Fortuna and Laima Tesserae [2]. Near the western edge of the map area, Fortuna Tessera is in contact with the highest moun-tain belt on Venus, Maxwell Montes. Deformational belts of Sigrun-Manto Fossae (extensional structures) and Au ra Dorsa (contractional structures) separate the tessera regions. Highly deformed terrains correspond to elevated regions and mildly deformed units are with low-lying areas. The sets of features within the V-2 quadrangle permit us to address the following important questions: (1) the timing and processes of crustal thickening/thinning, (2) the nature and origin of tesserae and deformation belts and their relation to crustal thickening processes, (3) the existence or absence of major evolutionary trends of volcanism and tectonics. The key feature in all of these problems is the regional sequence of events. Here we present description of units that occur in the V-2 quadrangle, their regional correlation chart (Fig. 1), and preliminary geological map of the region (Fig. 2).

  19. Thermal studies on a mechanical prototype of A BIS MDT chamber

    CERN Document Server

    Petridou, C; Wotschack, J; Zisis, A

    1998-01-01

    The deformations of a BIS MDT chamber owing to temperature gradients between the two multilayers and between the two Faraday cages were studied on a mechanical prototype. The influence of thermal insulation on the thermal behaviour of the chamber is also reported.

  20. Thermal expansion and spontaneous magnetostriction of R2Co7 intermetallic compounds

    International Nuclear Information System (INIS)

    Andreev, A.V.; Bartashevich, M.I.; Deryagin, A.V.; Zadvorkin, S.M.; Tarasov, E.N.

    1988-01-01

    Thermal expansion of R 2 Co 7 (R=Y, Nd, Gd, Tb) single crystals was invesigated by the method of X-ray dilatometry. Anomalous of thermal expansion, taking place during magnetic ordering and spin reorientation were used to determine linear and volumetric magnetistriction deformations. Constants of anisotropic magnetostriction of all R 2 Co 7 compounds with nonzero orbital moment of rare earth ion were calculated on the basis of single-ion model according to deformation values and with account of temperature dependences of the magnitude and direction of magnetic moment

  1. Predicting deformation and stress as a function of additive manufacturing process parameters for Europa drill

    Data.gov (United States)

    National Aeronautics and Space Administration — We will combine part-level FEM model of residual stresses with phase-field transformation model to predict deformation and cracking due to thermal stresses from the...

  2. Comparative Performance of PLZT and PVDF Pyroelectric Sensors Used to the Thermal Characterization of Liquid Samples

    Directory of Open Access Journals (Sweden)

    Gemima Lara Hernandez

    2013-01-01

    Full Text Available Among the photothermal methods, the photopyroelectric (PPE technique is a suitable method to determine thermal properties of different kinds of samples ranging from solids to liquids and gases. Polyvinylidene difluoride (PVDF is one of the most frequently used pyroelectric sensors in PPE technique but has the disadvantage that it can be easily deformed by the sample weight. This deformation could add a piezoelectric effect to the thermal parameters assessment; also PVDF has a narrow temperature operation range when compared with ceramic pyroelectric sensors. In order to minimize possible piezoelectric effects due to sensor deformation, a ceramic of lanthanum modified lead zirconate (PLZT was used as pyroelectric sensor in the PPE technique. Then, thermal diffusivity of some liquid samples was measured, by using the PPE configuration that denominated the thermal wave resonator cavity (TWRC, with a PLZT ceramic as pyroelectric detector. The performance obtained with the proposed ceramic in the TWRC configuration was compared with that obtained with PVDF by using the same configuration.

  3. Deformation mechanisms of nanotwinned Al

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xinghang [Texas A & M Univ., College Station, TX (United States)

    2016-11-10

    The objective of this project is to investigate the role of different types of layer interfaces on the formation of high density stacking fault (SF) in Al in Al/fcc multilayers, and understand the corresponding deformation mechanisms of the films. Stacking faults or twins can be intentionally introduced (via growth) into certain fcc metals with low stacking fault energy (such as Cu, Ag and 330 stainless steels) to achieve high strength, high ductility, superior thermal stability and good electrical conductivity. However it is still a major challenge to synthesize these types of defects into metals with high stacking fault energy, such as Al. Although deformation twins have been observed in some nanocrystalline Al powders by low temperature, high strain rate cryomilling or in Al at the edge of crack tip or indentation (with the assistance of high stress intensity factor), these deformation techniques typically introduce twins sporadically and the control of deformation twin density in Al is still not feasible. This project is designed to test the following hypotheses: (1) Certain type of layer interfaces may assist the formation of SF in Al, (2) Al with high density SF may have deformation mechanisms drastically different from those of coarse-grained Al and nanotwinned Cu. To test these hypotheses, we have performed the following tasks: (i) Investigate the influence of layer interfaces, stresses and deposition parameters on the formation and density of SF in Al. (ii) Understand the role of SF on the deformation behavior of Al. In situ nanoindentation experiments will be performed to probe deformation mechanisms in Al. The major findings related to the formation mechanism of twins and mechanical behavior of nanotwinned metals include the followings: 1) Our studies show that nanotwins can be introduced into metals with high stacking fault energy, in drastic contrast to the general anticipation. 2) We show two strategies that can effectively introduce growth twins in

  4. Deformation mechanisms of nanotwinned Al

    International Nuclear Information System (INIS)

    Zhang, Xinghang

    2016-01-01

    The objective of this project is to investigate the role of different types of layer interfaces on the formation of high density stacking fault (SF) in Al in Al/fcc multilayers, and understand the corresponding deformation mechanisms of the films. Stacking faults or twins can be intentionally introduced (via growth) into certain fcc metals with low stacking fault energy (such as Cu, Ag and 330 stainless steels) to achieve high strength, high ductility, superior thermal stability and good electrical conductivity. However it is still a major challenge to synthesize these types of defects into metals with high stacking fault energy, such as Al. Although deformation twins have been observed in some nanocrystalline Al powders by low temperature, high strain rate cryomilling or in Al at the edge of crack tip or indentation (with the assistance of high stress intensity factor), these deformation techniques typically introduce twins sporadically and the control of deformation twin density in Al is still not feasible. This project is designed to test the following hypotheses: (1) Certain type of layer interfaces may assist the formation of SF in Al, (2) Al with high density SF may have deformation mechanisms drastically different from those of coarse-grained Al and nanotwinned Cu. To test these hypotheses, we have performed the following tasks: (i) Investigate the influence of layer interfaces, stresses and deposition parameters on the formation and density of SF in Al. (ii) Understand the role of SF on the deformation behavior of Al. In situ nanoindentation experiments will be performed to probe deformation mechanisms in Al. The major findings related to the formation mechanism of twins and mechanical behavior of nanotwinned metals include the followings: 1) Our studies show that nanotwins can be introduced into metals with high stacking fault energy, in drastic contrast to the general anticipation. 2) We show two strategies that can effectively introduce growth twins in

  5. Effect of temperature change exerted on plastic deformation of SUS 304

    International Nuclear Information System (INIS)

    Niitsu, Yasushi; Ikegami, Kozo

    1985-01-01

    Under the condition of mechanical load, on which the thermal stress due to temperature change is superposed, the deformation behavior of structural materials is affected by not only loading history but also temperature history. Also at the time of working materials, the case that the relation between plastic deformation and temperature change becomes a problem is not few, such as cold working after hot rolling. In this study, the effect of temperature change exerted on the plastic deformation of SUS 304 stainless steel was examined, as this material has been frequently used as a high temperature structural material. That is, the plastic deformation behavior at a certain temperature after prestrain was applied at a different temperature was experimentally determined under various temperature and load conditions. Moreover, the quantitative evaluation of the results obtained was attempted by using the concept of an equal plastic strain curved surface. The test pieces and the experimental method, the behavior in uniaxial loading and the behavior in combined loading are reported. (Kako, I.)

  6. Microstructural change during creep deformation in a 10%Cr martensitic steel

    International Nuclear Information System (INIS)

    Kim, Sung Ho; Song, B. J.; Ryu, Woo Seog

    2001-01-01

    The relationship between creep deformation and microstructural changes in martensitic 10Cr-MoW steel has been studied. Transmission electron microscopy and image analyser were used to determine the variation of precipitates and martensite lath width size during creep deformation and aging. As precipitates are coarsened during creep deformation, dislocations become easy to move and the recovery proceeds rapidly. This leads to the growth of lath width. The average size of precipitates was linearly increased with creep time. On the other hand the growth rate of lath width is constant until tertiary creep, but the growth of lath width is accelerated during tertiary creep. It has been concluded that the growth behavior of lath width are consistent with creep deformation. Because the growth of lath width is controlled by the coarsening of precipitates it is important to form more stable precipitates in creep condition for improvement of creep properties of martensitic steel. Microstructure of martensitic steel is thermally very stable, so the size of precipitates and martensite lath width are hardly changed during aging

  7. Accelerated thermal and radiative ageing of hydrogenated NBR for DRC

    International Nuclear Information System (INIS)

    Mares, G.; Notingher, P.

    1996-01-01

    The accelerated thermal and gamma radiation ageing of HNBR carbon black-T80 has been studied by measuring the residual deformation under constant deflection -- DRC, in air, using a relevant equation for the relaxation phenomena. The residual deformation under constant deflection during the process of accelerated ageing is increasing but the structure of polymer answers in the proper manner to the mechanical stress. The degradation equations were obtained, using Alfrey model for the relaxation polymer subject to compression and an Arrhenius dependence for the chemical reaction rate. The inverted relaxation time for the thermal degradation is depending on the chemical reaction rate and the dose rate of gamma radiation

  8. Preliminary thermal/thermomechanical analyses of the Site Characterization Plan's Conceptual Design for a repository containing horizontally emplaced waste packages at the Deaf Smith County site

    International Nuclear Information System (INIS)

    Ghantous, N.Y.; Raines, G.E.

    1987-10-01

    This report presents thermal/thermomechanical analyses of the Site Characterization Plan Conceptual Design for horizontal package emplacement at the Deaf Smith County site, Texas. The repository was divided into three geometric regions. Then two-dimensional finite-element models were set up to approximate the three-dimensional nature of each region. Thermal and quasistatic thermomechanical finite-element analyses were performed to evaluate the thermal/thermomechanical responses of the three regions. The exponential-time creep law was used to represent the creep behavior of salt rock. The repository design was evaluated by comparing the thermal/thermomechanical responses obtained for the three regions with interim performance constraints. The preliminary results show that all the performance constraints are met except for those of the waste package. The following factors were considered in interpreting these results: (1) the qualitative description of the analytical responses; (2) the limitations of the analyses; and (3) either the conclusions based on overall evaluation of limitations and analytical results or the conclusions based on the fact that the repository design may be evaluated only after further analyses. Furthermore, a parametric analysis was performed to estimate the effect of material parameters on the predicted thermal/thermomechanical response. 23 refs., 34 figs., 9 tabs

  9. LMFBR thermal-striping evaluation

    International Nuclear Information System (INIS)

    Brunings, J.E.

    1982-10-01

    Thermal striping is defined as the fluctuating temperature field that is imposed on a structure when fluid streams at different temperatures mix in the vicinity of the structure surface. Because of the uncertainty in structural damage in LMFBR structures subject to thermal striping, EPRI has funded an effort for the Rockwell International Energy Systems Group to evaluate this problem. This interim report presents the following information: (1) a Thermal Striping Program Plan which identifies areas of analytic and experimental needs and presents a program of specific tasks to define damage experienced by ordinary materials of construction and to evaluate conservatism in the existing approach; (2) a description of the Thermal Striping Test Facility and its operation; and (3) results from the preliminary phase of testing to characterize the fluid environment to be applied in subsequent thermal striping damage experiments

  10. Thermal modelling. Preliminary site description. Forsmark area - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Jan; Back, Paer-Erik; Bengtsson, Anna; Laendell, Maerta [Geo Innova AB, Linkoeping (Sweden)

    2005-08-01

    This report presents the thermal site descriptive model for the Forsmark area, version 1.2. The main objective of this report is to present the thermal modelling work where data has been identified, quality controlled, evaluated and summarised in order to make an upscaling to lithological domain level possible. The thermal conductivity at canister scale has been modelled for two different lithological domains (RFM029 and RFM012, both dominated by granite to granodiorite (101057)). A main modelling approach has been used to determine the mean value of the thermal conductivity. Two alternative/complementary approaches have been used to evaluate the spatial variability of the thermal conductivity at domain level. The thermal modelling approaches are based on the lithological model for the Forsmark area, version 1.2 together with rock type models constituted from measured and calculated (from mineral composition) thermal conductivities. Results indicate that the mean of thermal conductivity is expected to exhibit a small variation between the different domains, 3.46 W/(mxK) for RFM012 to 3.55 W/(mxK) for RFM029. The spatial distribution of the thermal conductivity does not follow a simple model. Lower and upper 95% confidence limits are based on the modelling results, but have been rounded of to only two significant figures. Consequently, the lower limit is 2.9 W/(mxK), while the upper is 3.8 W/(mxK). This is applicable to both the investigated domains. The temperature dependence is rather small with a decrease in thermal conductivity of 10.0% per 100 deg C increase in temperature for the dominating rock type. There are a number of important uncertainties associated with these results. One of the uncertainties considers the representative scale for the canister. Another important uncertainty is the methodological uncertainties associated with the upscaling of thermal conductivity from cm-scale to canister scale. In addition, the representativeness of rock samples is

  11. Analysis Of Deformation And Microstructural Evolution In The Hot Forgingof The Ti-6Al-4V Alloy

    Directory of Open Access Journals (Sweden)

    Kukuryk M.

    2015-09-01

    Full Text Available The paper presents the analysis of the three-dimensional strain state for the cogging process of the Ti-6Al-4V alloy using the finite element method, assuming the rigid-plastic model of the deformed body. It reports the results of simulation studies on the metal flow pattern and thermal phenomena occurring in the hot cogging process conducted on three tool types. The computation results enable the determination of the distribution of effective strain, effective stress, mean stress and temperature within the volume of the blank. This solution has been complemented by adding the model of microstructure evolution during the cogging process. The numerical analysis was made using the DEFORM-3D consisting of a mechanical, a thermal and a microstructural parts. The comparison of the theoretical study and experimental test results indicates a potential for the developed model to be employed for predicting deformations and microstructure parameters.

  12. Temperature dependent mechanical properties and thermal activation plasticity of nanocrystalline and coarse grained Ni-18.75 at.% Fe alloy

    International Nuclear Information System (INIS)

    Tabachnikova, E D; Podolskiy, A V; Smirnov, S N; Psaruk, I A; Liao, P K

    2014-01-01

    Mechanical properties of Ni-18.75 at.% Fe in coarse grained (average grain size 15 gm) and nanocrystalline (average grain size 22 nm) states were studied in uniaxial compression in the temperature range 4.2-350 K. Temperature dependences of the flow stress, strain rate sensitivity and activation volume of plastic deformation were measured. The thermal activation analysis of the experimental data has been fulfilled for the the plastic deformation value of 2 %. It was shown that plastic deformation in temperature range from 35 to 350 K in both studied structural states has the thermally activated type. Comparative analysis of low temperature thermal activation plastic deformation was carried out for the alloy in coarse grained and nanocrystalline states. Empirical estimates of parameters of the dislocation interaction with local barriers and internal stress value estimates were obtained for the both studied structural states. Analysis of the results indicates that different mechanisms control the thermal activation plasticity of the Ni-18.75 at.% Fe alloy in coarse grained and nanocrystalline states. Possible mechanisms, which control plactisity of the studied states, are disscussed

  13. EXPERIMENTAL STUDY OF THERMAL AND STRAIN FIELDS DURING DEFORMATION OF EN ENCHELON FAULTS AND ITS GEOLOGICAL IMPLICATIONS

    Directory of Open Access Journals (Sweden)

    Ma Jin

    2010-01-01

    Full Text Available The article presents results of experimental studies using a bi-axial servo-control system to apply load on samples with extensional and compressional en echelon faults. During the experiments, variations of temperature and thermal images were recorded synchronously by a multi-path contact-type thermometric apparatus and a thermal image system, respectively. A digital CCD camera was employed to synchronously collect images of specimens’ surfaces. The digital speckle correlation method (DSCM was utilized to analyze the images and to define displacements and strain fields. Our experimental results show that temperature fields have clear responses to opposite stress states in the jog areas of both types of the en echelon faults. Prior to failure of the jog area, its temperature is the highest at the compressional en echelon faults and the lowest at the extensional en echelon faults. Records by DSCM give evidence that mean strain of the jog area is the highest at compressional en echelon faults and the lowest at the extensional en echelon faults. It is revealed that deformation of the en echelon faults occurs in two stages, developing from stress build-up and fault propagation in the jog area to unstable sliding along the fault. Correspondingly, the mechanism of heating-up converts from strain heating into friction heating. During the period of transformation of the temperature rising mechanism, three events are observed in the jog area and its vicinity. Analyses of our experimental results demonstrate that variations of temperatures in the jog area can be indicative of fault sliding and suggest sliding directions. Observations and studies of temperature changes during transformation of the temperature rising mechanism at sensitive portions of faults are of great importance for early detection of precursors of unstable slip on active faults.

  14. Examples of deformation-dependent flow simulations of conjunctive use with MF-OWHM

    Science.gov (United States)

    Hanson, Randall T.; Traum, Jonathan A.; Boyce, Scott E.; Schmid, Wolfgang; Hughes, Joseph D.

    2015-01-01

    The dependency of surface- and groundwater flows and aquifer hydraulic properties on deformation induced by changes in aquifer head is not accounted for in the standard version of MODFLOW. A new USGS integrated hydrologic model, MODFLOW-OWHM, incorporates this dependency by linking subsidence and mesh deformation with changes in aquifer transmissivity and storage coefficient, and with flows that also depend on aquifer characteristics and land-surface geometry. This new deformation-dependent approach is being used for the further development of the integrated Central Valley hydrologic model (CVHM) in California. Preliminary results from this application and from hypothetical test cases of similar systems show that changes in canal flows, stream seepage, and evapotranspiration from groundwater (ETgw) are sensitive to deformation. Deformation feedback has been shown to also have an indirect effect on conjunctive surface- and groundwater use components with increased stream seepage and streamflows influencing surface-water deliveries and return flows. In the Central Valley model, land subsidence may significantly degrade the ability of the major canals to deliver surface water from the Delta to the San Joaquin and Tulare basins. Subsidence can also affect irrigation demand and ETgw, which, along with altered surface-water supplies, causes a feedback response resulting in changed estimates of groundwater pumping for irrigation. This modeling feature also may improve the impact assessment of dewatering-induced land subsidence/uplift (following irrigation pumping or coal-seam gas extraction) on surface receptors, inter-basin transfers, and surface infrastructure integrity.

  15. Examples of deformation-dependent flow simulations of conjunctive use with MF-OWHM

    Directory of Open Access Journals (Sweden)

    R. T. Hanson

    2015-11-01

    Full Text Available The dependency of surface- and groundwater flows and aquifer hydraulic properties on deformation induced by changes in aquifer head is not accounted for in the standard version of MODFLOW. A new USGS integrated hydrologic model, MODFLOW-OWHM, incorporates this dependency by linking subsidence and mesh deformation with changes in aquifer transmissivity and storage coefficient, and with flows that also depend on aquifer characteristics and land-surface geometry. This new deformation-dependent approach is being used for the further development of the integrated Central Valley hydrologic model (CVHM in California. Preliminary results from this application and from hypothetical test cases of similar systems show that changes in canal flows, stream seepage, and evapotranspiration from groundwater (ETgw are sensitive to deformation. Deformation feedback has been shown to also have an indirect effect on conjunctive surface- and groundwater use components with increased stream seepage and streamflows influencing surface-water deliveries and return flows. In the Central Valley model, land subsidence may significantly degrade the ability of the major canals to deliver surface water from the Delta to the San Joaquin and Tulare basins. Subsidence can also affect irrigation demand and ETgw, which, along with altered surface-water supplies, causes a feedback response resulting in changed estimates of groundwater pumping for irrigation. This modeling feature also may improve the impact assessment of dewatering-induced land subsidence/uplift (following irrigation pumping or coal-seam gas extraction on surface receptors, inter-basin transfers, and surface infrastructure integrity.

  16. Thermal Properties of Algerian Diatomite, Study of the Possibility to Its Use in the Thermal Insulation

    Science.gov (United States)

    Hamdi, Boualem; Hamdi, Safia

    The chemical and physical properties of a Algerian diatomite were given before and after heat treatment and chemical with an aim of a use in the heat insulation of constructions. The preliminary results obtained showed that this material is extremely porous (porosity >70 %), characterized of a low density and a very low thermal conductivity. These promising properties support the use of this local material in the thermal insulation.

  17. Temperature and direction dependence of internal strain and texture evolution during deformation of uranium

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.W., E-mail: dbrown@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Bourke, M.A.M.; Clausen, B.; Korzekwa, D.R.; Korzekwa, R.C.; McCabe, R.J.; Sisneros, T.A.; Teter, D.F. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2009-06-25

    Depleted uranium is of current programmatic interest at Los Alamos National Lab due to its high density and nuclear applications. At room temperature, depleted uranium displays an orthorhombic crystal structure with highly anisotropic mechanical and thermal properties. For instance, the coefficient of thermal expansion is roughly 20 x 10{sup -6} deg. C{sup -1} in the a and c directions, but near zero or slightly negative in the b direction. The innate anisotropy combined with thermo-mechanical processing during manufacture results in spatially varying residual stresses and crystallographic texture, which can cause distortion, and failure in completed parts, effectively wasting resources. This paper focuses on the development of residual stresses and textures during deformation at room and elevated temperatures with an eye on the future development of computational polycrystalline plasticity models based on the known micro-mechanical deformation mechanisms of the material.

  18. Deformation of a Volcanic Edifice by Pore Pressurization: An Analog Approach

    Science.gov (United States)

    Hyman, D.; Bursik, M. I.

    2015-12-01

    Volcanic flank destabilization, preceded by pressurization-induced surface deformation or weakening, presents a significant hazard at stratovolcanoes with ample supply of magmatic volatiles or preexisting hydrothermal systems as in Bezymianny- and Bandai-type eruptions, respectively. Deformation is also an important sign of the nature of unrest at large calderas such as Long Valley, USA. Previous studies of volcanic inflation have focused primarily on the role of ascending magma. Relatively few studies have centered on surface deformation caused by pressurization from other volcanic fluids, including exsolved volatiles and pressurized hydrothermal systems. Most investigations of pore-pressurization have focused on numerical modelling of pore pressure transients. In analog experiments presented here, pore-filling fluids are injected into the base of a damp sand medium without exceeding dike propagating pressures, simulating the pressurization and bulk-permeable flow of volatile fluids through volcanic systems. The experiments examine surface deformation from a range of source depths and pressures as well as edifice geometries. 3D imaging is possible through use of the Microsoft® Kinect™ sensor, which allows for the generation of high-resolution, high frame rate, lab-scale Digital Elevation Models (DEMs). After initial processing to increase signal-to-noise ratio, surface deformation is measured using the DEM time-series generated by the Kinect™. Analysis of preliminary experiments suggests that inflation is possible up to approx. 10 % of pressure source depth. We also show that the Kinect™ sensor is useful in analog volcanological studies, an environment to which it is well-suited.

  19. Changes in the state of heat-resistant steel induced by repeated hot deformation

    Science.gov (United States)

    Lyubimova, Lyudmila L.; Fisenko, Roman N.; Tashlykov, Alexander A.; Tabakaev, Roman B.

    2018-01-01

    This work deals with the problems of structural regeneration by thermal restoration treatment (TRT). These include the lack of a structural sign showing that TRT is possible, a consensus on TRT modes, the data on the necessary relaxation depth of residual stresses, or criteria of structural restoration. Performing a TRT without solving these problems may deteriorate the properties of steel or even accelerate its destruction. With this in view, the purpose of this work is to determine experimentally how the residual stress state changes under thermal and mechanical loads in order to specify the signs of the restoration of structure and structural stability. The object of this research is unused 12Cr1MoV steel that has been aged naturally for 13 years. Using X-ray dosimetry with X-ray spectral analysis, we study the distribution of internal residual stresses of the first kind during the repeated hot deformation. After repeated thermal deformation, the sample under study transforms from a viscoelastic Maxwell material into a Kelvin-Voigt material, which facilitates structural stabilization. A sign of this is the relaxation limit increase, prevention of continuous decay of an α-solid solution of iron and restoration of the lattice parameter.

  20. ABOUT THE STUDY OF THE THERMAL STRESS FOR NAVAL SYSTEMS

    Directory of Open Access Journals (Sweden)

    ANASASE PRUIU

    2016-06-01

    Full Text Available In this paper are presented and analyzed the effects of thermal expansion on gas evacuation piping from naval power plants an d technical protection possibilities to prevent structures from deformations; also are analyzed the possibilities for the use of thermal expansion for tightening the main screws for power plant propulsion.

  1. Deformation-specific and deformation-invariant visual object recognition: pose vs identity recognition of people and deforming objects

    Directory of Open Access Journals (Sweden)

    Tristan J Webb

    2014-04-01

    Full Text Available When we see a human sitting down, standing up, or walking, we can recognise one of these poses independently of the individual, or we can recognise the individual person, independently of the pose. The same issues arise for deforming objects. For example, if we see a flag deformed by the wind, either blowing out or hanging languidly, we can usually recognise the flag, independently of its deformation; or we can recognise the deformation independently of the identity of the flag. We hypothesize that these types of recognition can be implemented by the primate visual system using temporo-spatial continuity as objects transform as a learning principle. In particular, we hypothesize that pose or deformation can be learned under conditions in which large numbers of different people are successively seen in the same pose, or objects in the same deformation. We also hypothesize that person-specific representations that are independent of pose, and object-specific representations that are independent of deformation and view, could be built, when individual people or objects are observed successively transforming from one pose or deformation and view to another. These hypotheses were tested in a simulation of the ventral visual system, VisNet, that uses temporal continuity, implemented in a synaptic learning rule with a short-term memory trace of previous neuronal activity, to learn invariant representations. It was found that depending on the statistics of the visual input, either pose-specific or deformation-specific representations could be built that were invariant with respect to individual and view; or that identity-specific representations could be built that were invariant with respect to pose or deformation and view. We propose that this is how pose-specific and pose-invariant, and deformation-specific and deformation-invariant, perceptual representations are built in the brain.

  2. Monitoring of the thermal deformations on polymer parts using a vision system

    DEFF Research Database (Denmark)

    Dalla Costa, Giuseppe; Madruga, Daniel González; De Chiffre, Leonardo

    2017-01-01

    Dimensional measurements in production environment are affected by non‐controlled temperature conditions. In the case of polymer parts the high thermal expansion coefficient leads to significant dimensional changes. In order to achieve high accuracy in dimensional measurements, thermal deformatio...

  3. Thermal stability of a highly-deformed warm-rolled tungsten plate in the temperature range 1100 °C to 1250 °C

    DEFF Research Database (Denmark)

    Alfonso Lopez, Angel; Juul Jensen, Dorte; Luo, G.-N.

    2015-01-01

    plastic strain by 90% thickness reduction was investigated by isothermal annealing for up to 190 h in the temperature range between 1100 °C and 1250 °C. Vickers hardness testing allowed tracking the changes in mechanical properties caused by recovery and recrystallization. The hardness evolution could......Pure tungsten is considered as armor material for the most critical parts of fusion reactors (i.e. the divertor and the first wall), among other reasons due to its high melting point (3422 °C) and recrystallization temperature. The thermal stability of a pure tungsten plate warm-rolled to a high...... suggest that large plastic deformations (e.g. applied during shaping) are only suitable to produce tungsten components to be used at relatively low temperatures (up to 900 °C for a 2 years lifespan). Higher operation temperatures will lead to fast degradation of the microstructure during operation....

  4. Coordinated Mapping of Sea Ice Deformation Features with Autonomous Vehicles

    Science.gov (United States)

    Maksym, T.; Williams, G. D.; Singh, H.; Weissling, B.; Anderson, J.; Maki, T.; Ackley, S. F.

    2016-12-01

    Decreases in summer sea ice extent in the Beaufort and Chukchi Seas has lead to a transition from a largely perennial ice cover, to a seasonal ice cover. This drives shifts in sea ice production, dynamics, ice types, and thickness distribution. To examine how the processes driving ice advance might also impact the morphology of the ice cover, a coordinated ice mapping effort was undertaken during a field campaign in the Beaufort Sea in October, 2015. Here, we present observations of sea ice draft topography from six missions of an Autonomous Underwater Vehicle run under different ice types and deformation features observed during autumn freeze-up. Ice surface features were also mapped during coordinated drone photogrammetric missions over each site. We present preliminary results of a comparison between sea ice surface topography and ice underside morphology for a range of sample ice types, including hummocked multiyear ice, rubble fields, young ice ridges and rafts, and consolidated pancake ice. These data are compared to prior observations of ice morphological features from deformed Antarctic sea ice. Such data will be useful for improving parameterizations of sea ice redistribution during deformation, and for better constraining estimates of airborne or satellite sea ice thickness.

  5. Preliminary analysis of K-DEMO thermal hydraulic system using MELCOR; Parametric study of hydrogen explosion

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sung Bo; Lim, Soo Min; Bang, In Cheol [UNIST, Ulsan (Korea, Republic of)

    2016-10-15

    K-DEMO (Korean fusion demonstration reactor) is future reactor for the commercializing the fusion power generation. The Design of K-DEMO is similar to that of ITER but the fusion energy generation is much bigger because ITER is experimental reactor. For this reason, K-DEMO uses more fusion reaction with bigger amount of tritium. Higher fusion power means more neutron generation that can irradiate the structure around fusion plasma. Fusion reactor can produce many kinds of radioactive material in the accident. Because of this hazard, preliminary safety analysis is mandatory before its construction. Concern for safety problem of accident of fusion/fission reactor has been growing after Fukushima accident which is severe accident from unexpected disaster. To model the primary heat transfer system, in this study, MARS-KS thermal hydraulic analysis is referred. Lee et al. and Kim et al. conducted thermal hydraulic analysis using MARS-KS and multiple module simulation to deal with the phenomena of first wall corrosion for each plasma pulse. This study shows the relationship between vacuum vessel rupture area and source term leakage after hydrogen explosion. For the conservative study, first wall heating is not terminated because the heating inside the vacuum vessel increase the pressure inside VV. Pressurizer, steam generator and turbine is not damaged. 6.69 kg of tritiated water (HTO) and 1 ton of dust is modeled which is ITER guideline. The entire system of K-DEMO is smaller than that of ITER. For this reason, lots of aerosol is release into environment although the safety system like DS is maintained. This result shows that the safety system of K-DEMO should use much more safety system.

  6. Radioactive waste shredding: Preliminary evaluation

    International Nuclear Information System (INIS)

    Soelberg, N.R.; Reimann, G.A.

    1994-07-01

    The critical constraints for sizing solid radioactive and mixed wastes for subsequent thermal treatment were identified via a literature review and a survey of shredding equipment vendors. The types and amounts of DOE radioactive wastes that will require treatment to reduce the waste volume, destroy hazardous organics, or immobilize radionuclides and/or hazardous metals were considered. The preliminary steps of waste receipt, inspection, and separation were included because many potential waste treatment technologies have limits on feedstream chemical content, physical composition, and particle size. Most treatment processes and shredding operations require at least some degree of feed material characterization. Preliminary cost estimates show that pretreatment costs per unit of waste can be high and can vary significantly, depending on the processing rate and desired output particle size

  7. Thermal modelling. Preliminary site description Laxemar subarea - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Jan; Wrafter, John; Back, Paer-Erik; Laendell, Maerta [Geo Innova AB, Linkoeping (Sweden)

    2006-02-15

    This report presents the thermal site descriptive model for the Laxemar subarea, version 1.2. The main objective of this report is to present the thermal modelling work where data has been identified, quality controlled, evaluated and summarised in order to make an upscaling to lithological domain level possible. The thermal conductivity at canister scale has been modelled for five different lithological domains: RSMA (Aevroe granite), RSMBA (mixture of Aevroe granite and fine-grained dioritoid), RSMD (quartz monzodiorite), RSME (diorite/gabbro) and RSMM (mix domain with high frequency of diorite to gabbro). A base modelling approach has been used to determine the mean value of the thermal conductivity. Four alternative/complementary approaches have been used to evaluate the spatial variability of the thermal conductivity at domain level. The thermal modelling approaches are based on the lithological domain model for the Laxemar subarea, version 1.2 together with rock type models based on measured and calculated (from mineral composition) thermal conductivities. For one rock type, Aevroe granite (501044), density loggings have also been used in the domain modelling in order to evaluate the spatial variability within the Aevroe granite. This has been possible due to an established relationship between density and thermal conductivity, valid for the Aevroe granite. Results indicate that the means of thermal conductivity for the various domains are expected to exhibit a variation from 2.45 W/(m.K) to 2.87 W/(m.K). The standard deviation varies according to the scale considered, and for the 0.8 m scale it is expected to range from 0.17 to 0.29 W/(m.K). Estimates of lower tail percentiles for the same scale are presented for all five domains. The temperature dependence is rather small with a decrease in thermal conductivity of 1.1-5.3% per 100 deg C increase in temperature for the dominant rock types. There are a number of important uncertainties associated with these

  8. Thermally-driven Coupled THM Processes in Shales

    Science.gov (United States)

    Rutqvist, J.

    2017-12-01

    Temperature changes can trigger strongly coupled thermal-hydrological-mechanical (THM) processes in shales that are important to a number of subsurface energy applications, including geologic nuclear waste disposal and hydrocarbon extraction. These coupled processes include (1) direct pore-volume couplings, by thermal expansion of trapped pore-fluid that triggers instantaneous two-way couplings between pore fluid pressure and mechanical deformation, and (2) indirect couplings in terms of property changes, such as changes in mechanical stiffness, strength, and permeability. Direct pore-volume couplings have been studied in situ during borehole heating experiments in shale (or clay stone) formations at Mont Terri and Bure underground research laboratories in Switzerland and France. Typically, the temperature changes are accompanied with a rapid increase in pore pressure followed by a slower decrease towards initial (pre-heating) pore pressure. Coupled THM modeling of these heater tests shows that the pore pressure increases because the thermal expansion coefficient of the fluid is much higher than that of the porous clay stone. Such thermal pressurization induces fluid flow away from the pressurized area towards areas of lower pressure. The rate of pressure increase and magnitude of peak pressure depends on the rate of heating, pore-compressibility, and permeability of the shale. Modeling as well as laboratory experiments have shown that if the pore pressure increase is sufficiently large it could lead to fracturing of the shale or shear slip along pre-existing bedding planes. Another set of data and observations have been collected associated with studies related to concentrated heating and cooling of oil-shales and shale-gas formations. Heating may be used to enhance production from tight oil-shale, whereas thermal stimulation has been attempted for enhanced shale-gas extraction. Laboratory experiments on shale have shown that strength and elastic deformation

  9. Analysis Of Deformation And Microstructural Evolution In The Hot Forging Of The Ti-6Al-4V Alloy

    Directory of Open Access Journals (Sweden)

    Kukuryk M.

    2015-06-01

    Full Text Available The paper presents the analysis of the three-dimensional strain state for the cogging process of the Ti-6Al-4V alloy using the finite element method, assuming the rigid-plastic model of the deformed body. It reports the results of simulation studies on the metal flow pattern and thermal phenomena occurring in the hot cogging process conducted on three tool types. The computation results enable the determination of the distribution of effective strain, effective stress, mean stress and temperature within the volume of the blank. This solution has been complemented by adding the model of microstructure evolution during the cogging process. The numerical analysis was made using the DEFORM-3D consisting of a mechanical, a thermal and a microstructural parts. The comparison of the theoretical study and experimental test results indicates a potential for the developed model to be employed for predicting deformations and microstructure parameters.

  10. Thermal processes evaluation for RWMC wastes

    International Nuclear Information System (INIS)

    1991-01-01

    The objective of this activity was to provide a white paper that identifies, collects information, and presents a preliminary evaluation of ''core'' thermal technologies that could be applied to RWMC stored and buried mixed waste. This paper presents the results of the following activities: General thermal technology identification, collection of technical and cost information on each technology, identification of thermal technologies applicable to RWMC waste, evaluation of each technology as applied to RWMC waste in seven process attributes, scoring each technology on a one to five scale (five highest) in each process attribute. Reaching conclusions about the superiority of one technology over others is not advised based on this preliminary study alone. However, the highly rated technologies (i.e., overall score of 2.9 or better) are worthy of a more detailed evaluation. The next step should be a more detailed evaluation of the technologies that includes onsite visits with operational facilities, preconceptual treatment facility design analysis, and visits with developers for emerging technologies. 2 figs., 6 tabs

  11. Deformation and collapse of zircaloy fuel rod cladding into plenum axial gaps

    International Nuclear Information System (INIS)

    Pfennigwerth, P.L.; Gorscak, D.A.; Selsley, I.A.

    1983-01-01

    To minimize support structure, blanket and reflector fuel rods of the thoria urania-fueled Light Water Breeder Reactor (LWBR) were designed with non-freestanding Zircaloy-4 cladding. An analytical model was developed to predict deformation of unirradiated cladding into axial gaps of fuel rod plenum regions where it is unsupported. This model uses the ACCEPT finite element computer program to calculate elastic-plastic deformation of cladding due to external pressure. The finite element is 20-node, triquadratic, isoparametric, and 3-dimensional. Its curved surface permits accurate modeling of the tube geometry, including geometric nonuniformities such as circumferential wall thickness variation and initial tube out-of-roundness. Progressive increases in axial gap length due to cladding elongation and fuel stack shrinkage are modeled, as are deformations of fuel pellets and stainless steel support sleeves which bound plenum axial gaps in LWBR type blanket fuel rods. Zircaloy-4 primary and secondary thermal creep representations were developed from uniaxial creep testing of fuel rod tubing. Creep response to multi-axial loading is modeled with a variation of Hill's formulation for anisotropic materials. Coefficients accounting for anisotropic thermal creep in Zircaloy-4 tubes were developed from creep testing of externally pressurized tubes having fixed axial gaps in the range 2.5 cm to 5.7 cm and radial clearances over simulated fuel pellets ranging from zero to 0.089 mm. (orig./RW)

  12. Verification of the active deformation compensation system of the LMT/GTM by end-to-end simulations

    Science.gov (United States)

    Eisentraeger, Peter; Suess, Martin

    2000-07-01

    The 50 m LMT/GTM is exposed to the climatic conditions at 4,600 m height on Cerro La Negra, Mexico. For operating the telescope to the challenging requirements of its millimeter objective, an active approach for monitoring and compensating the structural deformations (Flexible Body Compensation FBC) is necessary. This system includes temperature sensors and strain gages for identifying large scale deformations of the reflector backup structure, a laser system for measuring the subreflector position, and an inclinometer system for measuring the deformations of the alidade. For compensating the monitored deformations, the telescope is equipped with additional actuators for active control of the main reflector surface and the subreflector position. The paper describes the verification of the active deformation system by finite element calculations and MATLAB simulations of the surface accuracy and the pointing including the servo under the operational wind and thermal conditions.

  13. Radon in thermal waters and radon risk in chosen thermal water spas in V4 countries - preliminary results

    International Nuclear Information System (INIS)

    Holy, K.; Blahusiak, P.; Muellerova, M.; Grzadziel, D.; Kozak, K.; Mazur, J.; Kovacs, T.; Nagy, E.; Shahrokhi, A.; Neznal, M.; Neznal, M.

    2014-01-01

    The territory of V4 countries is rich in thermal springs. Some boreholes reach a depth of 2000 m and temperatures up to 70 grad C. 222 Rn concentrations in some thermal waters can exceed 1000 Bq/l, however this concentration is not constant. In V4 countries, there is a long tradition in using thermal waters in spa care. In thermal spas, radon is released from the water, and is transported along with its decay products into human respiratory tract, which is potentially harmful to human health. Thus, controlling the levels of radon concentration in thermal waters, homes and workplaces of spas is justified. The aim of this project is the study of radon 222 Rn concentration in thermal waters and in thermal spas in V4 countries. The measurements are carried out a few times during at least one year in order to observe seasonal variability. The obtained results will serve to determine annual effective doses for employees who spend ca. 8 hours a day inside spa buildings. It will be also possible to assess the effective doses for patients (users) of the pools with the highest registered radon concentrations. We carry out measurements in 3 existing thermal water spas in each of the countries: Slovakia, Poland and Hungary, and in 1 thermal water spas in the Czech Republic,according to choice of partners. (authors)

  14. A fundamental discussion of what triggers localized deformation in geological materials

    Science.gov (United States)

    Peters, Max; Paesold, Martin; Poulet, Thomas; Herwegh, Marco; Regenauer-Lieb, Klaus; Veveakis, Manolis

    2015-04-01

    critical amount of dissipative work translated into heat over the diffusive capacity of the system by an instability study designed for such materials (Gruntfest, 1963). With respect to our numerical experiments, this critical parameter determines the timing when the entire amount of deformation energy translated into heat cannot be diffusively transported out of the system anymore. The resulting local temperature rise then induces strain localization. In contrast to classical shear heating scenarios with (catastrophic) thermal runaways, temperature variations of less than 1 K are sufficient for this localization mode to occur due to the balance between heat producing (e.g. dislocation creep) and consuming (grain growth) processes in the present setup. We demonstrate that this rise in latent heat is sufficient to provoke grain growth, operating as an endothermic reaction, stabilizing the simulated localized structure in turn. Various localized ductile structures, such as folded or boudinaged layers, can therefore be placed at the same material failure mode due to fundamental energy bifurcations triggered by dissipative work out of homogeneous state. Finally, we will discuss situations, in which structural heterogeneities are considered negligible and where the energy theory described here plays an underlying role by means of a comparison between numerical experiments and natural examples. REFERENCES Austin, N. and Evans, B. (2007). Paleowattmeters: A scaling relation for dynamically recrystallized grain size. Geology, 35. Gruntfest, I.J. (1963). Thermal feedback in liquid flow, plane shear at constant stress. Transactions of the Society of Rheology, 7. Hansen, L.N. and Zimmermann, M.E. and Dillman, A.M. and Kohlstedt, D.L (2012). Strain localization in olivine aggregates at high temperature: a laboratory comparison of constant-strain-rate and constant-stress boundary conditions. Earth and Planetary Science Letters, 333-334. Herwegh, M., Poulet, T., Karrech, A. and

  15. An On-Chip RBC Deformability Checker Significantly Improves Velocity-Deformation Correlation

    Directory of Open Access Journals (Sweden)

    Chia-Hung Dylan Tsai

    2016-10-01

    Full Text Available An on-chip deformability checker is proposed to improve the velocity–deformation correlation for red blood cell (RBC evaluation. RBC deformability has been found related to human diseases, and can be evaluated based on RBC velocity through a microfluidic constriction as in conventional approaches. The correlation between transit velocity and amount of deformation provides statistical information of RBC deformability. However, such correlations are usually only moderate, or even weak, in practical evaluations due to limited range of RBC deformation. To solve this issue, we implemented three constrictions of different width in the proposed checker, so that three different deformation regions can be applied to RBCs. By considering cell responses from the three regions as a whole, we practically extend the range of cell deformation in the evaluation, and could resolve the issue about the limited range of RBC deformation. RBCs from five volunteer subjects were tested using the proposed checker. The results show that the correlation between cell deformation and transit velocity is significantly improved by the proposed deformability checker. The absolute values of the correlation coefficients are increased from an average of 0.54 to 0.92. The effects of cell size, shape and orientation to the evaluation are discussed according to the experimental results. The proposed checker is expected to be useful for RBC evaluation in medical practices.

  16. A new in situ technique for studying deformation and fracture in thin film ductile/brittle laminates

    International Nuclear Information System (INIS)

    Hackney, S.A.; Milligan, W.W.

    1991-01-01

    A new technique for studying deformation and fracture of thin film ductile/brittle laminates is described. The laminates are prepared by sputtering a brittle coating on top of an electropolished TEM thin foil. The composites are then strained in situ in the TEM. In this preliminary investigation, the composites consisted of a ductile aluminum substrate and a brittle silicon coating. Cracks in the brittle film grew discontinuously in bursts several micrometers in length. The crack opening displacement initiated plastic deformation in the ductile film, thus dissipating energy and allowing crack arrest. The interface was well bonded, and delamination was not observed. Due to the good interfacial bond and the crack opening behind the crack tip, it was possible to study very large plastic deformations and ductile fracture in the aluminum in situ, without buckling of the foil. The possibility of micromechanical modeling of the fracture behavior is briefly discussed. (orig.)

  17. Thermal modelling. Preliminary site description Simpevarp subarea - version 1.2

    International Nuclear Information System (INIS)

    Sundberg, Jan; Back, Paer-Erik; Bengtsson, Anna; Laendell, Maerta

    2005-08-01

    This report presents the thermal site descriptive model for the Simpevarp subarea, version 1.2. The main objective of this report is to present the thermal modelling work where data has been identified, quality controlled, evaluated and summarised in order to make an upscaling to lithological domain level possible. The thermal conductivity at possible canister scale has been modelled for four different lithological domains (RSMA01 (Aevroe granite), RSMB01 (Fine-grained dioritoid), RSMC01 (mixture of Aevroe granite and Quartz monzodiorite), and RSMD01 (Quartz monzodiorite)). A main modelling approach has been used to determine the mean value of the thermal conductivity. Three alternative/complementary approaches have been used to evaluate the spatial variability of the thermal conductivity at domain level. The thermal modelling approaches are based on the lithological model for the Simpevarp subarea, version 1.2 together with rock type models constituted from measured and calculated (from mineral composition) thermal conductivities. For one rock type, the Aevroe granite (501044), density loggings within the specific rock type has also been used in the domain modelling in order to consider the spatial variability within the Aevroe granite. This has been possible due to the presented relationship between density and thermal conductivity, valid for the Aevroe granite. Results indicate that the mean of thermal conductivity is expected to exhibit only a small variation between the different domains, from 2.62 W/(m.K) to 2.80 W/(m.K). The standard deviation varies according to the scale considered and for the canister scale it is expected to range from 0.20 to 0.28 W/(m.K). Consequently, the lower confidence limit (95% confidence) for the canister scale is within the range 2.04-2.35 W/(m.K) for the different domains. The temperature dependence is rather small with a decrease in thermal conductivity of 1.1-3.4% per 100 deg C increase in temperature for the dominating rock

  18. Thermal processing systems for TRU mixed waste

    International Nuclear Information System (INIS)

    Eddy, T.L.; Raivo, B.D.; Anderson, G.L.

    1992-01-01

    This paper presents preliminary ex situ thermal processing system concepts and related processing considerations for remediation of transuranic (TRU)-contaminated wastes (TRUW) buried at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Anticipated waste stream components and problems are considered. Thermal processing conditions required to obtain a high-integrity, low-leachability glass/ceramic final waste form are considered. Five practical thermal process system designs are compared. Thermal processing of mixed waste and soils with essentially no presorting and using incineration followed by high temperature melting is recommended. Applied research and development necessary for demonstration is also recommended

  19. Investigation of inhomogeneous deformation in band amorphous alloys at constant heating rate

    Science.gov (United States)

    Fedorov, Victor; Berezner, Arseniy; Pluzhnikova, Tatiana; Beskrovnyi, Anatolyi

    2017-11-01

    The present paper contains investigations of the creep process in the cobalt-based amorphous metallic alloy within the temperature range from 300 up to 1023 K. In all the curves of deformation there were observed jumps and dying oscillations. It is noted that the creep of the sample ribbons is unstable and results in the thinning of ribbons with tightening and crimping. There is suggested the mechanism of inhomogeneous deformation, which takes place in course of the process of creep under intermittent heating. For the evaluation of amorphism in the treated samples there have been carried out neutron-graphical and X-ray diffraction investigations, as well as thermal analysis.

  20. New Methods for Imaging Evaluation of Chest Wall Deformities

    Directory of Open Access Journals (Sweden)

    Ana Lain

    2017-12-01

    Full Text Available AimThe purpose of this study is to describe the development of an external 3-dimensional (3D scanner as a noninvasive method for imaging chest wall deformities. It allows objective assessment, reconstruction of the area of interest, and evaluation of the severity of the deformity by using external indexes.External 3D scanning systemThe OrtenBodyOne scanner (Orten, Lyon, France uses depth sensors to scan the entire 3D external body surface of a patient. The depth sensors combine structured light with two classic computer vision techniques: depth from focus and depth from stereo. The data acquired are processed and analyzed using the Orten-Clinic software.Materials and methodsTo investigate the performance of the device, a preliminary prospective study (January 2015–March 2016 was carried out in patients attending our hospital chest wall deformities unit. In total, 100 patients (children and young adults with pectus excavatum or pectus carinatum, treated by surgery or non-operative methods were included. In patients undergoing non-operative treatment, external 3D scanning was performed monthly until complete correction was achieved. In surgically treated patients, scanning was done before and after surgical correction. In 42 patients, computed tomography (CT was additionally performed and correlations between the Haller index calculated by CT and the external Haller index using external scanning were investigated using a Student’s test (r = 0.83.ConclusionExternal scanning is an effective, objective, radiation-free means to diagnose and follow-up patients with chest wall deformities. Externally measured indexes can be used to evaluate the severity of these conditions and the treatment outcomes.

  1. Adaptive Restoration of Airborne Daedalus AADS1268 ATM Thermal Data

    International Nuclear Information System (INIS)

    D. Yuan; E. Doak; P. Guss; A. Will

    2002-01-01

    To incorporate the georegistration and restoration processes into airborne data processing in support of U.S. Department of Energy's nuclear emergency response task, we developed an adaptive restoration filter for airborne Daedalus AADS1268 ATM thermal data based on the Wiener filtering theory. Preliminary assessment shows that this filter enhances the detectability of small weak thermal anomalies in AADS1268 thermal images

  2. The Influence of the Content of Furfuryl Alcohol Monomer on the Process of Moulding Sand's Thermal Destruction

    Directory of Open Access Journals (Sweden)

    Dobosz St. M.

    2014-10-01

    Full Text Available The article discusses the issue of the influence of furfuryl alcohol content in resin binders on properties of moulding sand at elevated temperature. Reducing the share of this component - due to the requirements of the European Union regarding its toxicity - may cause a decrease in temperature of moulding sands’ destruction and, consequently, the thermal deformation of moulds and the creation of many casting defects. The study examined the impact of the furfuryl alcohol content of the thermal destruction processes and on the strength of the moulding sand at an ambient temperature and the tendency to thermal deformation.

  3. A Sandwiched/Cracked Flexible Film for Multi-Thermal Monitoring and Switching Devices

    KAUST Repository

    Tai, Yanlong; Chen, Tao; Lubineau, Gilles

    2017-01-01

    Polydimethylsiloxane (PDMS)-based flexible films have substantiated advantages in various sensing applications. Here, we demonstrate the highly sensitive and programmable thermal-sensing capability (thermal index, B, up to 126 × 103 K) of flexible films with tunable sandwiched microstructures (PDMS/cracked single-walled carbon nanotube (SWCNT) film/PDMS) when a thermal stimulus is applied. We found that this excellent performance results from the following features of the film's structural and material design: (1) the sandwiched structure allows the film to switch from a three-dimensional to a two-dimensional in-plane deformation and (2) the stiffness of the SWCNT film is decreased by introducing microcracks that make deformation easy and that promote the macroscopic piezoresistive behavior of SWCNT crack islands and the microscopic piezoresistive behavior of SWCNT bundles. The PDMS layer is characterized by a high coefficient of thermal expansion (α = 310 × 10-6 K-1) and low stiffness (∼2 MPa) that allow for greater flexibility and higher temperature sensitivity. We determined the efficacy of our sandwiched, cracked, flexible films in monitoring and switching flexible devices when subjected to various stimuli, including thermal conduction, thermal radiation, and light radiation.

  4. A Sandwiched/Cracked Flexible Film for Multi-Thermal Monitoring and Switching Devices

    KAUST Repository

    Tai, Yanlong

    2017-08-30

    Polydimethylsiloxane (PDMS)-based flexible films have substantiated advantages in various sensing applications. Here, we demonstrate the highly sensitive and programmable thermal-sensing capability (thermal index, B, up to 126 × 103 K) of flexible films with tunable sandwiched microstructures (PDMS/cracked single-walled carbon nanotube (SWCNT) film/PDMS) when a thermal stimulus is applied. We found that this excellent performance results from the following features of the film\\'s structural and material design: (1) the sandwiched structure allows the film to switch from a three-dimensional to a two-dimensional in-plane deformation and (2) the stiffness of the SWCNT film is decreased by introducing microcracks that make deformation easy and that promote the macroscopic piezoresistive behavior of SWCNT crack islands and the microscopic piezoresistive behavior of SWCNT bundles. The PDMS layer is characterized by a high coefficient of thermal expansion (α = 310 × 10-6 K-1) and low stiffness (∼2 MPa) that allow for greater flexibility and higher temperature sensitivity. We determined the efficacy of our sandwiched, cracked, flexible films in monitoring and switching flexible devices when subjected to various stimuli, including thermal conduction, thermal radiation, and light radiation.

  5. Insights into the deformation behavior of the CrMnFeCoNi high-entropy alloy revealed by elevated temperature nanoindentation

    Energy Technology Data Exchange (ETDEWEB)

    Maier-Kiener, Verena [Montanuniversitat Leoben, Leoben (Austria); Schuh, Benjamin [Austrian Academy of Sciences, Leoben (Austria); George, Easo P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Clemens, Helmut [Montanuniversitat Leoben, Leoben (Austria); Hohenwarter, Anton [Austrian Academy of Sciences, Leoben (Austria)

    2017-07-27

    A CrMnFeCoNi high-entropy alloy was investigated by nanoindentation from room temperature to 400 °C in the nanocrystalline state and cast plus homogenized coarse-grained state. In the latter case a < 100 >-orientated grain was selected by electron back scatter diffraction for nanoindentation. It was found that hardness decreases more strongly with increasing temperature than Young’s modulus, especially for the coarse-grained state. The modulus of the nanocrystalline state was slightly higher than that of the coarse-grained one. For the coarse-grained sample a strong thermally activated deformation behavior was found up to 100–150 °C, followed by a diminishing thermally activated contribution at higher testing temperatures. For the nanocrystalline state, different temperature dependent deformation mechanisms are proposed. At low temperatures, the governing processes appear to be similar to those in the coarse-grained sample, but with increasing temperature, dislocation-grain boundary interactions likely become more dominant. Finally, at 400 °C, decomposition of the nanocrystalline alloy causes a further reduction in thermal activation. Furthermore, this is rationalized by a reduction of the deformation controlling internal length scale by precipitate formation in conjunction with a diffusional contribution.

  6. Thermal safety analysis of a dry storage cask for the Korean standard spent fuel - 16159

    International Nuclear Information System (INIS)

    Cha, Jeonghun; Kim, S.N.; Choi, K.W.

    2009-01-01

    A conceptual dry storage facility, which is based on a commercial dry storage facility, was designed for the Korea standard spent nuclear fuel (SNF) and preliminary thermal safety analysis was performed in this study. To perform the preliminary thermal analysis, a thermal analysis method was proposed. The thermal analysis method consists of 2 parts. By using the method, the surface temperature of the storage canister corresponding to the SNF clad temperature was calculated and the adequate air duct area was decided using the calculation result. The initial temperature of the facility was calculated and the fire condition and half air duct blockage were analyzed. (authors)

  7. Spatiotemporal Patterns of Precipitation-Modulated Landslide Deformation From Independent Component Analysis of InSAR Time Series

    Science.gov (United States)

    Cohen-Waeber, J.; Bürgmann, R.; Chaussard, E.; Giannico, C.; Ferretti, A.

    2018-02-01

    Long-term landslide deformation is disruptive and costly in urbanized environments. We rely on TerraSAR-X satellite images (2009-2014) and an improved data processing algorithm (SqueeSAR™) to produce an exceptionally dense Interferometric Synthetic Aperture Radar ground deformation time series for the San Francisco East Bay Hills. Independent and principal component analyses of the time series reveal four distinct spatial and temporal surface deformation patterns in the area around Blakemont landslide, which we relate to different geomechanical processes. Two components of time-dependent landslide deformation isolate continuous motion and motion driven by precipitation-modulated pore pressure changes controlled by annual seasonal cycles and multiyear drought conditions. Two components capturing more widespread seasonal deformation separate precipitation-modulated soil swelling from annual cycles that may be related to groundwater level changes and thermal expansion of buildings. High-resolution characterization of landslide response to precipitation is a first step toward improved hazard forecasting.

  8. Microstructure and Texture in Surface Deformation Layer of Al-Zn-Mg-Cu Alloy Processed by Milling

    Directory of Open Access Journals (Sweden)

    CHEN Yanxia

    2017-12-01

    Full Text Available The microstructural and crystallographic features of the surface deformation layer in Al-Zn-Mg-Cu alloy induced by milling were investigated by means of transmission electron microscopy (TEM and precession electron diffraction (PED assisted nanoscale orientation mapping. The result shows that the surface deformation layer is composed by the top surface of equiaxed nanograins/ultrafine grains and the subsurface of lamellar nanograins/ultrafine grains surrounded by coarse grain boundary precipitates (GBPs. The recrystallized nanograins/ultrafine grains in the deformation layer show direct evidence that dynamic recrystallization plays an important role in grain refining process. The GBPs and grain interior precipitates (GIPs show a great difference in size and density with the matrix due to the thermally and mechanically induced precipitate redistribution. The crystallographic texture of the surface deformation layer is proved to be a mixture of approximate copper{112}, rotated cube{001} and F {111}. The severe shear deformation of the surface induced by milling is responsible for the texture evolution.

  9. Thermomechanical characterization of a membrane deformable mirror

    International Nuclear Information System (INIS)

    Morse, Kathleen A.; McHugh, Stuart L.; Fixler, Jeff

    2008-01-01

    A membrane deformable mirror has been investigated for its potential use in high-energy laser systems. Experiments were performed in which the deformable mirror was heated with a 1 kW incandescent lamp and the thermal profile, the wavefront aberrations, and the mechanical displacement of the membrane were measured. A finite element model was also developed. The wavefront characterization experiments showed that the wavefront degraded with heating. Above a temperature of 35 deg. C, the wavefront characterization experiments indicated a dramatic increase in the high-order wavefront modes before the optical beam became immeasurable in the sensors. The mechanical displacement data of the membrane mirror showed that during heating, the membrane initially deflected towards the heat source and then deflected away from the heat source. Finite element analysis (FEA) predicted a similar displacement behavior as shown by the mechanical displacement data but over a shorter time scale and a larger magnitude. The mechanical displacement data also showed that the magnitude of membrane displacement increased with the experiments that involved higher temperatures. Above a temperature of 35 deg. C, the displacement data showed that random deflections as a function of time developed and that the magnitude of these deflections increased with increased temperature. We concluded that convection, not captured in the FEA, likely played a dominant role in mirror deformation at temperatures above 35 deg. C

  10. q-deformed Weinberg-Salam model and q-deformed Maxwell equations

    International Nuclear Information System (INIS)

    Alavi, S.A.; Sarbishaei, M.; Mokhtari, A.

    2000-01-01

    We study the q-deformation of the gauge part of the Weinberg-Salam model and show that the q-deformed theory involves new interactions. We then obtain q-deformed Maxwell equations from which magnetic monopoles appear naturally. (author)

  11. A kinematical model for the plastic deformation of face-centred cubic polycrystals

    International Nuclear Information System (INIS)

    Leffers, T.

    1975-01-01

    During the plastic deformation of a polycrystalline material the deformation of the individual grain must be adjusted to the deformation of the surrounding grains so that material continuity is maintained. This continuity condition is the essential feature distinguishing polycrystal deformation from single-crystal deformation. In the present work it is attempted to explain how the continuity condition is fulfilled in face-centred cubic polycrystals. The early treatments of the plastic deformation of polycrystalline materials were aimed directly at the formulation of a ''dynamical'' theory, i.e. it was the intention to cover the magnitude of the stresses involved as well as the slip processes producing the deformation. It is argued that rolling texture is a good tool for a necessary intermediate stage of establishing a ''kinematical'' model describing the slip processes, but not the magnitude of the necessary stresses. Three aspects of rolling texture are considered: (a) the development of the rolling textures found experimentally in face-centred cubic materials can be computer-simulated on the basis of models for the plastic deformation that only involve (111) slip; (b) experimentally that the widely accepted twinning theory for the transition in f.c.c. rolling texture does not reflect the behaviour of real materials; and (c) it is shown that the texture transition is thermally activated with an activation energy corresponding to that of cross slip. An electron-microscopical investigation of the slip process operating during rolling of f.c.c. polycrystals is also included. On the basis of the computer simulation of the texture formation supplemented by the experimental results a kinematical model is developed for the plastic deformation of f.c.c. polycrystals by rolling. In the proposed model the material continuity is maintained by inhomogeneous slip processes, combined with homogeneous multiple glide when the cross-slip frequency is high. (author)

  12. Holographic superconductor in a deformed four-dimensional STU model

    Energy Technology Data Exchange (ETDEWEB)

    Pourhassan, B.; Bagheri-Mohagheghi, M.M. [Damghan University, School of Physics, Damghan (Iran, Islamic Republic of)

    2017-11-15

    In this paper, we consider a deformed STU model in four dimensions including both electric and magnetic charges. Using the AdS/CFT correspondence, we study holographic superconductors and obtain transport properties like electrical and thermal conductivities. We obtain transport properties in terms of the magnetic charge of the black hole and interpret it as the magnetic monopole of dual field theory. We find that the presence of the magnetic charge is necessary to have maximum conductivities, and the existence of a magnetic monopole with a critical charge (137 e) to reach the maximum superconductivity is important. Also, we show that the thermal conductivity increases with increasing of the magnetic charge. It may be concluded that the origin of superconductivity is the magnetic monopole. (orig.)

  13. Anisotropic thermal expansion behaviors of copper matrix in β-eucryptite/copper composite

    International Nuclear Information System (INIS)

    Wang Lidong; Xue Zongwei; Qiao Yingjie; Fei, W.D.

    2012-01-01

    Highlights: ► The thermal expansion behaviors of Cu matrix were studied by in situ XRD. ► The expansion of Cu{1 1 1} plane is linear, that of Cu{2 0 0} is nonlinear. ► The anisotropic thermal expansion of Cu is related to the twinning of Cu matrix. ► The twinning of Cu matrix makes the CTE of the composite increasing. - Abstract: A β-eucryptite/copper composite was fabricated by spark plasma sintering process. The thermal expansion behaviors of Cu matrix of the composite were studied by in situ X-ray diffraction during heating process. The results show that Cu matrix exhibits anisotropic thermal expansion behaviors for different crystallographic directions, the expansion of Cu{1 1 1} plane is linear in the temperature range from 20 °C to 300 °C and the expansion of Cu{2 0 0} is nonlinear with a inflection at about 180 °C. The microstructures of Cu matrix before and after thermal expansion testing were investigated using transmission electronic microscope. The anisotropic thermal expansion behavior is related to the deformation twinning formed in the matrix during heating process. At the same time, the deformation twinning of Cu matrix makes the average coefficient of thermal expansion of the composite increase.

  14. Experimental and numerical studies of various thermal sleeves subjected to severe cyclic thermal shocks

    International Nuclear Information System (INIS)

    Masson, J.C.; Moinereau, D.

    1990-01-01

    During the first operating years of nuclear power plants of different countries, damage was encountered on thermal sleeves used as nozzle protection. Following this discovery studies were initiated to determine the causes and to find solutions. At first a problem of vibration was found and easily solved by reducing gaps and reinforcing the welding of the sleeves. But preliminary tests with cyclic thermal shocks showed a risk of fatigue crack initiation and propagation both in the sleeve fixation and in the nozzle. Therefore a large research and development program was led principally by EDF laboratories of Les Renardieres, to demonstrate the absence of nocivity of thermal shocks during the plants life time [fr

  15. Thermal modelling. Preliminary site description Simpevarp subarea - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Jan; Back, Paer-Erik; Bengtsson, Anna; Laendell, Maerta [Geo Innova AB, Linkoeping (Sweden)

    2005-08-15

    This report presents the thermal site descriptive model for the Simpevarp subarea, version 1.2. The main objective of this report is to present the thermal modelling work where data has been identified, quality controlled, evaluated and summarised in order to make an upscaling to lithological domain level possible. The thermal conductivity at possible canister scale has been modelled for four different lithological domains (RSMA01 (Aevroe granite), RSMB01 (Fine-grained dioritoid), RSMC01 (mixture of Aevroe granite and Quartz monzodiorite), and RSMD01 (Quartz monzodiorite)). A main modelling approach has been used to determine the mean value of the thermal conductivity. Three alternative/complementary approaches have been used to evaluate the spatial variability of the thermal conductivity at domain level. The thermal modelling approaches are based on the lithological model for the Simpevarp subarea, version 1.2 together with rock type models constituted from measured and calculated (from mineral composition) thermal conductivities. For one rock type, the Aevroe granite (501044), density loggings within the specific rock type has also been used in the domain modelling in order to consider the spatial variability within the Aevroe granite. This has been possible due to the presented relationship between density and thermal conductivity, valid for the Aevroe granite. Results indicate that the mean of thermal conductivity is expected to exhibit only a small variation between the different domains, from 2.62 W/(m.K) to 2.80 W/(m.K). The standard deviation varies according to the scale considered and for the canister scale it is expected to range from 0.20 to 0.28 W/(m.K). Consequently, the lower confidence limit (95% confidence) for the canister scale is within the range 2.04-2.35 W/(m.K) for the different domains. The temperature dependence is rather small with a decrease in thermal conductivity of 1.1-3.4% per 100 deg C increase in temperature for the dominating rock

  16. Analysis of the thermo-mechanical deformations in a hot forging tool by numerical simulation

    International Nuclear Information System (INIS)

    L-Cancelos, R.; Varas, F.; Viéitez, I.; Martín, E.

    2016-01-01

    Although programs have been developed for the design of tools for hot forging, its design is still largely based on the experience of the tool maker. This obliges to build some test matrices and correct their errors to minimize distortions in the forged piece. This phase prior to mass production consumes time and material resources, which makes the final product more expensive. The forging tools are usually constituted by various parts made of different grades of steel, which in turn have different mechanical properties and therefore suffer different degrees of strain. Furthermore, the tools used in the hot forging are exposed to a thermal field that also induces strain or stress based on the degree of confinement of the piece. Therefore, the mechanical behaviour of the assembly is determined by the contact between the different pieces. The numerical simulation allows to analyse different configurations and anticipate possible defects before tool making, thus, reducing the costs of this preliminary phase. In order to improve the dimensional quality of the manufactured parts, the work presented here focuses on the application of a numerical model to a hot forging manufacturing process in order to predict the areas of the forging die subjected to large deformations. The thermo-mechanical model developed and implemented with free software (Code-Aster) includes the strains of thermal origin, strains during forge impact and contact effects. The numerical results are validated with experimental measurements in a tooling set that produces forged crankshafts for the automotive industry. The numerical results show good agreement with the experimental tests. Thereby, a very useful tool for the design of tooling sets for hot forging is achieved. (paper)

  17. Analysis of the thermo-mechanical deformations in a hot forging tool by numerical simulation

    Science.gov (United States)

    L-Cancelos, R.; Varas, F.; Martín, E.; Viéitez, I.

    2016-03-01

    Although programs have been developed for the design of tools for hot forging, its design is still largely based on the experience of the tool maker. This obliges to build some test matrices and correct their errors to minimize distortions in the forged piece. This phase prior to mass production consumes time and material resources, which makes the final product more expensive. The forging tools are usually constituted by various parts made of different grades of steel, which in turn have different mechanical properties and therefore suffer different degrees of strain. Furthermore, the tools used in the hot forging are exposed to a thermal field that also induces strain or stress based on the degree of confinement of the piece. Therefore, the mechanical behaviour of the assembly is determined by the contact between the different pieces. The numerical simulation allows to analyse different configurations and anticipate possible defects before tool making, thus, reducing the costs of this preliminary phase. In order to improve the dimensional quality of the manufactured parts, the work presented here focuses on the application of a numerical model to a hot forging manufacturing process in order to predict the areas of the forging die subjected to large deformations. The thermo-mechanical model developed and implemented with free software (Code-Aster) includes the strains of thermal origin, strains during forge impact and contact effects. The numerical results are validated with experimental measurements in a tooling set that produces forged crankshafts for the automotive industry. The numerical results show good agreement with the experimental tests. Thereby, a very useful tool for the design of tooling sets for hot forging is achieved.

  18. Heat transfer and thermal stress analysis in fluid-structure coupled field

    International Nuclear Information System (INIS)

    Li, Ming-Jian; Pan, Jun-Hua; Ni, Ming-Jiu; Zhang, Nian-Mei

    2015-01-01

    In this work, three-dimensional simulation on conjugate heat transfer in a fluid-structure coupled field was carried out. The structure considered is from the dual-coolant lithium-lead (DCLL) blanket, which is the key technology of International Thermo-nuclear Experimental Reactor (ITER). The model was developed based on finite element-finite volume method and was employed to investigate mechanical behaviours of Flow Channel Insert (FCI) and heat transfer in the blanket under nuclear reaction. Temperature distribution, thermal deformation and thermal stresses were calculated in this work, and the effects of thermal conductivity, convection heat transfer coefficient and flow velocity were analyzed. Results show that temperature gradients and thermal stresses of FCI decrease when FCI has better heat conductivity. Higher convection heat transfer coefficient will result in lower temperature, thermal deformations and stresses in FCI. Analysis in this work could be a theoretical basis of blanket optimization. - Highlights: • We use FVM and FEM to investigate FCI structural safety considering heat transfer and FSI effects. • Higher convective heat transfer coefficient is beneficial for the FCI structural safety without much affect to bulk flow temperature. • Smaller FCI thermal conductivity can better prevent heat leakage into helium, yet will increase FCI temperature gradient and thermal stress. • Three-dimensional simulation on conjugate heat transfer in a fluid-structure coupled field was carried out

  19. CFD simulation of a dry scroll vacuum pump with clearances, solid heating and thermal deformation

    Science.gov (United States)

    Spille-Kohoff, A.; Hesse, J.; Andres, R.; Hetze, F.

    2017-08-01

    Although dry scroll vacuum pumps (DSPV) are essential devices in many different industrial processes, the CFD simulation of such pumps is not widely used and often restricted to simplified cases due to its complexity: The working principle with a fixed and an orbiting scroll leads to working chambers that are changing in time and are connected through moving small radial and axial clearances in the range of 10 to 100 μm. Due to the low densities and low mass flow rates in vacuum pumps, it is important to include heat transfer towards and inside the solid components. Solid heating is very slow compared to the scroll revolution speed and the gas behaviour, thus a special workflow is necessary to reach the working conditions in reasonable simulation times. The resulting solid temperature is then used to compute the thermal deformation, which usually results in gap size changes that influence leakage flows. In this paper, setup steps and results for the simulation of a DSVP are shown and compared to theoretical and experimental results. The time-varying working chambers are meshed with TwinMesh, a hexahedral meshing programme for positive displacement machines. The CFD simulation with ANSYS CFX accounts for gas flow with compressibility and turbulence effects, conjugate heat transfer between gas and solids, and leakage flows through the clearances. Time-resolved results for torques, chamber pressure, mass flow, and heat flow between gas and solids are shown, as well as time- and space-resolved results for pressure, velocity, and temperature for different operating conditions of the DSVP.

  20. Transient thermal-mechanical coupling behavior analysis of mechanical seals during start-up operation

    Science.gov (United States)

    Gao, B. C.; Meng, X. K.; Shen, M. X.; Peng, X. D.

    2016-05-01

    A transient thermal-mechanical coupling model for a contacting mechanical seal during start-up has been developed. It takes into consideration the coupling relationship among thermal-mechanical deformation, film thickness, temperature and heat generation. The finite element method and multi-iteration technology are applied to solve the temperature distribution and thermal-mechanical deformation as well as their evolution behavior. Results show that the seal gap transforms from negative coning to positive coning and the contact area of the mechanical seal gradually decreases during start-up. The location of the maximum temperature and maximum contact pressure move from the outer diameter to inside diameter. The heat generation and the friction torque increase sharply at first and then decrease. Meanwhile, the contact force decreases and the fluid film force and leakage rate increase.

  1. Experiment and numerical analysis of the NPP pressurizer auxiliary spray line submitted to large thermal shocks

    International Nuclear Information System (INIS)

    Couterot, C.; Geyer, P.; Proix, J.M.

    1994-03-01

    The pressurizer auxiliary spray line of PWR nuclear power plants may be submitted to severe temperature transients during upset conditions: a 325 deg C cold thermal shock in one second is followed by a 200 deg C hot thermal shock. For such transients, the RCC-M French design code rules that prevent the ratcheting deformation hazard are not respected for the components with thickness transition. Consequently, Electricite de France has realized twenty thermal cycles under pressure on a representative mock-up. During these tests, many temperature, strain and diametral variations were measured. No significant ratcheting deformation was detected on all components, except on the 6'' x 2'' x 6'' T-piece, where a weak progressive diameter increase was observed during a few cycles. Moreover, computations of a 2'' socket welding were made with the non linear kinematic hardening Chaboche model which also showed a weak progressive deformation behaviour. (authors). 7 figs., 7 refs

  2. Interface bonding of SA508-3 steel under deformation and high temperature diffusion

    Science.gov (United States)

    Xu, Bin; Shao, Chunjuan; Sun, Mingyue

    2018-05-01

    There are mainly two parameters affecting high temperature interface bonding: deformation and diffusion. To study these two parameters, interface bonding of SA508-3 bainitic steel at 1100°C are simulated by gleeble3500 thermal simulator. The results show that interface of SA508-3 steel can be bonded under deformation and high temperature. For a specimen pressed at 1100°C without further high temperature diffusion, a reduction ratio of 30% can make the interface begun to bond, but the interface is still part of the grain boundary and small grains exist near the interface. When reduction ratio reaches 50%, the interface can be completely bonded and the microstructure near the interface is the same as that of the base material. When deformation is small, long time diffusion can also help the interface bonding. The results show that when the diffusion time is long enough, the interface under small deformation can also be bonded. For a specimen holding for 24h at 1100°C, only 13% reduction ratio is enough for interface bonding.

  3. Analysis of piping response to thermal and operational transients

    International Nuclear Information System (INIS)

    Wang, C.Y.

    1987-01-01

    The reactor piping system is an extremely complex three-dimensional structure. Maintaining its structural integrity is essential to the safe operation of the reactor and the steam-supply system. In the safety analysis, various transient loads can be imposed on the piping which may cause plastic deformation and possible damage to the system, including those generated from hydrodynamic wave propagations, thermal and operational transients, as well as the seismic events. At Argonne National Laboratory (ANL), a three-dimensional (3-D) piping code, SHAPS, aimed for short-duration transients due to wave propagation, has been developed. Since 1984, the development work has been shifted to the long-duration accidents originating from the thermal and operational transient. As a result, a new version of the code, SHAPS-2, is being established. This paper describes many features related to this later development. To analyze piping response generated from thermal and operational transients, a 3-D implicit finite element algorithm has been developed for calculating the hoop, flexural, axial, and torsional deformations induced by the thermomechanical loads. The analysis appropriately accounts for stresses arising from the temperature dependence of the elastic material properties, the thermal expansion of the materials, and the changes in the temperature-dependent yield surface. Thermal softening, failure, strain rate, creep, and stress ratching can also be considered

  4. Preliminary thermal expansion screening data for tuffs

    International Nuclear Information System (INIS)

    Lappin, A.R.

    1980-03-01

    A major variable in evaluating the potential of silicic tuffs for use in geologic disposal of heat-producing nuclear wastes is thermal expansion. Results of ambient-pressure linear expansion measurements on a group of tuffs that vary treatly in porosity and mineralogy are presente here. Thermal expansion of devitrified welded tuffs is generally linear with increasing temperature and independent of both porosity and heating rate. Mineralogic factors affecting behavior of these tuffs are limited to the presence or absence of cristobalite and altered biotite. The presence of cristobalite results in markedly nonlinear expansion above 200 0 C. If biotite in biotite-hearing rocks alters even slightly to expandable clays, the behavior of these tuffs near the boiling point of water can be dominated by contraction of the expandable phase. Expansion of both high- and low-porosity tuffs containing hydrated silicic glass and/or expandable clays is complex. The behavior of these rocks appears to be completely dominated by dehydration of hydrous phases and, hence, should be critically dependent on fluid pressure. Valid extrapolation of the ambient-pressure results presented here to depths of interest for construction of a nuclear-waste repository will depend on a good understanding of the interaction of dehydration rates and fluid pressures, and of the effects of both micro- and macrofractures on the response of tuff masss

  5. Mechanical and structural behaviour of uranium α, β, γ phases during plastic deformation

    International Nuclear Information System (INIS)

    Prunier, C.; Collot, C.

    1981-06-01

    High temperature behaviour of rich and poor uranium alloys in α, β and γ crystalline structures is studied: dynamic recrystallization phenomena begins only in α and β phases high temperature range, high strength and brittle β phase shows a very large ductility above 700 0 C. Dynamic recrystallization in γ phase rich alloys is observed only if large energy is available. Recrystallization is a thermal actived phenomena localised at grain boundary, dependant with alloy concentration and crystalline structure. β phase activation energy and deformation rate for dynamic recrystallization beginning are the most important in relation with structure complexity; both temperature and rate deformation are dynamic recrystallization factors [fr

  6. Thermal stress ratcheting analysis of a time-hardening structure

    International Nuclear Information System (INIS)

    Hada, Kazuhiko

    1999-01-01

    Thermal stress ratcheting and shakedown is analyzed for a time-hardening structure: the yield stress increases as time goes on under exposure to neutron irradiation or thermal aging. New three modes of ratcheting and shakedown are identified as transition to other deformation modes. Stress regimes and thermal ratchet strains are formulated as a function of time-increasing yield stress. Moreover, a new model of trouble occurrence frequency as a modification to a bath-tube curve is proposed for calculating a time period of a thermal cycle. Application of the proposed formulation tells us a benefit of taking into account the time hardening due to neutron irradiation. (author)

  7. Deformation twinning in a creep-deformed nanolaminate structure

    International Nuclear Information System (INIS)

    Hsiung, Luke L

    2010-01-01

    The underlying mechanism of deformation twinning occurring in a TiAl-(γ)/Ti 3 Al-(α 2 ) nanolaminate creep deformed at elevated temperatures has been studied. Since the multiplication and propagation of lattice dislocations in both γ and α 2 thin lamellae are very limited, the total flow of lattice dislocations becomes insufficient to accommodate the accumulated creep strains. Consequently, the movement of interfacial dislocations along the laminate interfaces, i.e., interface sliding, becomes an alternative deformation mode of the nanolaminate structure. Pile-ups of interfacial dislocations occur when interfacial ledges and impinged lattice dislocations act as obstacles to impede the movement of interfacial dislocations. Deformation twinning can accordingly take place to relieve a stress concentration resulting from the pile-up of interfacial dislocations. An interface-controlled twinning mechanism driven by the pile-up and dissociation of interfacial dislocations is accordingly proposed.

  8. Deformation twinning in a creep-deformed nanolaminate structure

    Science.gov (United States)

    Hsiung, Luke L.

    2010-10-01

    The underlying mechanism of deformation twinning occurring in a TiAl-(γ)/Ti3Al-(α2) nanolaminate creep deformed at elevated temperatures has been studied. Since the multiplication and propagation of lattice dislocations in both γ and α2 thin lamellae are very limited, the total flow of lattice dislocations becomes insufficient to accommodate the accumulated creep strains. Consequently, the movement of interfacial dislocations along the laminate interfaces, i.e., interface sliding, becomes an alternative deformation mode of the nanolaminate structure. Pile-ups of interfacial dislocations occur when interfacial ledges and impinged lattice dislocations act as obstacles to impede the movement of interfacial dislocations. Deformation twinning can accordingly take place to relieve a stress concentration resulting from the pile-up of interfacial dislocations. An interface-controlled twinning mechanism driven by the pile-up and dissociation of interfacial dislocations is accordingly proposed.

  9. Phase lag deduced information in photo-thermal actuation for nano-mechanical systems characterization

    NARCIS (Netherlands)

    Bijster, R.J.F.; Vreugd, J. de; Sadeghian Marnani, H.

    2014-01-01

    In photo-thermal actuation, heat is added locally to a micro-cantilever by means of a laser. A fraction of the irradiation is absorbed, yielding thermal stresses and deformations in the structure. Harmonic modulation of the laser power causes the cantilever to oscillate. Moreover, a phase lag is

  10. The deformation of wax patterns and castings in investment casting technology

    Directory of Open Access Journals (Sweden)

    A. Herman

    2012-01-01

    Full Text Available The dimensional accuracy of the final casting of Inconel alloy 738 LC is affected by many aspects. One of them is the choice of method and time of cooling wax model for precision investment casting. The main objective was to study the initial deformation of the complex shape of the casting of the rotor blades. Various approaches have been tested for cooling wax pattern. When wax models are cooling on the air, without clamping in jig for cooling, deviations from the ideal shape of the casting are very noticeable (up to 8 mm and most are in extreme positions of the model. When blade is cooled in fixing jig in water environment, the resulting deviations compared with cooling in air are significantly larger, sometimes up to 10 mm. This itself does not mean that the final shape of the casting is dimensionally more accurate with usage of wax models, which have deviations from the ideal position smaller. Another deformation occurs when shell mould is produced around wax pattern and furthermore deformations emerge while casting of blade is cooling. This paper demonstrates first steps in describing complex process of deformations of Inconel alloy blades produced with investment casting technology by comparing results from thermal imagery, simulations in foundry simulation software ProCAST 2010 and measurements from CNC scanning system Carl Zeiss MC 850. Conclusions are so far not groundbreaking, but it seems deformations of wax pattern and deformations of castings do in some cases cancel each other by having opposite directions. Describing entirely whole process of deformations will help increase precision of blade castings so that models at the beginning and blades in the end are the same.

  11. Investigation of coolant thermal mixing within 28-element CANDU fuel bundles using the ASSERT-PV thermal hydraulics code

    International Nuclear Information System (INIS)

    Lightston, M.F.; Rock, R.

    1996-01-01

    This paper presents the results of a study of the thermal mixing of single-phase coolant in 28-element CANDU fuel bundles under steady-state conditions. The study, which is based on simulations performed using the ASSERT-PV thermal hydraulic code, consists of two main parts. In the first part the various physical mechanisms that contribute to coolant mixing are identified and their impact is isolated via ASSERT-PV simulations. The second part is concerned with development of a preliminary model suitable for use in the fuel and fuel channel code FACTAR to predict the thermal mixing that occurs between flow annuli. (author)

  12. Low Pressure Nuclear Thermal Rocket (LPNTR) concept

    International Nuclear Information System (INIS)

    Ramsthaler, J.H.

    1991-01-01

    A background and a description of the low pressure nuclear thermal system are presented. Performance, mission analysis, development, critical issues, and some conclusions are discussed. The following subject areas are covered: LPNTR's inherent advantages in critical NTR requirement; reactor trade studies; reference LPNTR; internal configuration and flow of preliminary LPNTR; particle bed fuel assembly; preliminary LPNTR neutronic study results; multiple LPNTR engine concept; tank and engine configuration for mission analysis; LPNTR reliability potential; LPNTR development program; and LPNTR program costs

  13. Influence of thermal reduced depolarization on a repetition-frequency laser amplifier and compensation

    Institute of Scientific and Technical Information of China (English)

    Xin-ying Jiang; Xiong-wei Yan; Zhen-guo Wang; Jian-gang Zheng; Ming-zhong Li; Jing-qin Su

    2015-01-01

    Thermal stress can induce birefringence in a laser medium, which can cause depolarization of the laser. The depolarization effect will be very severe in a high-average-power laser. Because the depolarization will make the frequency doubling efficiency decline, it should be compensated. In this paper, the thermal characteristics of two kinds of materials are analyzed in respect of temperature, thermal deformation and thermal stress. The depolarization result from thermal stress was simulated. Depolarization on non-uniform pumping was also simulated, and the compensation method is discussed.

  14. Thermal shock induced dynamics of a spacecraft with a flexible deploying boom

    Science.gov (United States)

    Shen, Zhenxing; Li, Huijian; Liu, Xiaoning; Hu, Gengkai

    2017-12-01

    The dynamics in the process of deployment of a flexible extendible boom as a deployable structure on the spacecraft is studied. For determining the thermally induced vibrations of the boom subjected to an incident solar heat flux, an axially moving thermal-dynamic beam element based on the absolute nodal coordinate formulation which is able to precisely describe the large displacement, rotation and deformation of flexible body is presented. For the elastic forces formulation of variable-length beam element, the enhanced continuum mechanics approach is adopted, which can eliminate the Poisson locking effect, and take into account the tension-bending-torsion coupling deformations. The main body of the spacecraft, modeled as a rigid body, is described using the natural coordinates method. In the derived nonlinear thermal-dynamic equations of rigid-flexible multibody system, the mass matrix is time-variant, and a pseudo damping matrix which is without actual energy dissipation, and a heat conduction matrix which is relative to the moving speed and the number of beam element are arisen. Numerical results give the dynamic and thermal responses of the nonrotating and spinning spacecraft, respectively, and show that thermal shock has a significant influence on the dynamics of spacecraft.

  15. Deformation in Metallic Glass: Connecting Atoms to Continua

    Science.gov (United States)

    Hinkle, Adam R.; Falk, Michael L.; Rycroft, Chris H.; Shields, Michael D.

    Metallic glasses like other amorphous solids experience strain localization as the primary mode of failure. However, the development of continuum constitutive laws which provide a quantitative description of disorder and mechanical deformation remains an open challenge. Recent progress has shown the necessity of accurately capturing fluctuations in material structure, in particular the statistical changes in potential energy of the atomic constituents during the non-equilibrium process of applied shear. Here we directly cross-compare molecular dynamics shear simulations of a ZrCu glass with continuum shear transformation zone (STZ) theory representations. We present preliminary results for a methodology to coarse-grain detailed molecular dynamics data with the goal of initializing a continuum representation in the STZ theory. NSF Grants Awards 1107838, 1408685, and 0801471.

  16. Local thermal property analysis by scanning thermal microscopy of an ultrafine-grained copper surface layer produced by surface mechanical attrition treatment

    Energy Technology Data Exchange (ETDEWEB)

    Guo, F.A. [Suzhou Institute for Nonferrous Metals Processing Technology, No. 200 Shenxu Road, Suzhou Industrial Park, Suzhou 215021 (China) and Unite de Thermique et d' Analyse Physique, Laboratoire d' Energetique et d' Optique, Universite de Reims, BP 1039, 51687 Reims Cedex 2 (France)]. E-mail: guofuan@yahoo.com; JI, Y.L. [Suzhou Institute for Nonferrous Metals Processing Technology, No. 200 Shenxu Road, Suzhou Industrial Park, Suzhou 215021 (China); Trannoy, N. [Unite de Thermique et d' Analyse Physique, Laboratoire d' Energetique et d' Optique, Universite de Reims, BP 1039, 51687 Reims Cedex 2 (France); Lu, J. [LASMIS, Universite de Technologie de Troyes, 12 Rue Marie Curie, Troyes 10010 (France)

    2006-06-15

    Scanning thermal microscopy (SThM) was used to map thermal conductivity images in an ultrafine-grained copper surface layer produced by surface mechanical attrition treatment (SMAT). It is found that the deformed surface layer shows different thermal conductivities that strongly depend on the grain size of the microstructure: the thermal conductivity of the nanostructured surface layer decreases obviously when compared with that of the coarse-grained matrix of the sample. The role of the grain boundaries in thermal conduction is analyzed in correlation with the heat conduction mechanism in pure metal. A theoretical approach, based on this investigation, was used to calculate the heat flow from the probe tip to the sample and then estimate the thermal conductivities at different scanning positions. Experimental results and theoretical calculation demonstrate that SThM can be used as a tool for the thermal property and microstructural analysis of ultrafine-grained microstructures.

  17. A Numerical Analysis on the Local Deformation of a Spacer Grid Structure for Nuclear Fuel Cells

    International Nuclear Information System (INIS)

    Jang, Myung-Geun; Na, Geum Ju; Kim, Jong-Bong; Shin, Hyunho

    2016-01-01

    The result of a preliminary numerical investigation on local deformation characteristics of a multi-layered spacer-grid structure with five guide tubes is reported based on implicit finite element analysis. For the numerical analysis, displacements of top and bottom cross sections of each guide tube in a single-layer model were constrained while a lateral displacement was imposed on the single layer. Unlike the impact hammer test that is generally employed to characterize the deformation characteristics of the space-grid structure, the buckling phenomenon occurs locally in this study; it takes place at the inner grids around each tube and the degree of bucking is more apparent for tubes near the lateral surface where the lateral displacement was imposed. (paper)

  18. Investigation of anisotropic thermal transport in cross-linked polymers

    Science.gov (United States)

    Simavilla, David Nieto

    Thermal transport in lightly cross-linked polyisoprene and polybutadine subjected to uniaxial elongation is investigated experimentally. We employ two experimental techniques to assess the effect that deformation has on this class of materials. The first technique, which is based on Forced Rayleigh Scattering (FRS), allows us to measure the two independent components of the thermal diffusivity tensor as a function of deformation. These measurements along with independent measurements of the tensile stress and birefringence are used to evaluate the stress-thermal and stress-optic rules. The stress-thermal rule is found to be valid for the entire range of elongations applied. In contrast, the stress-optic rule fails for moderate to large stretch ratios. This suggests that the degree of anisotropy in thermal conductivity depends on both orientation and tension in polymer chain segments. The second technique, which is based on infrared thermography (IRT), allows us to measure anisotropy in thermal conductivity and strain induced changes in heat capacity. We validate this method measurements of anisotropic thermal conductivity by comparing them with those obtained using FRS. We find excellent agreement between the two techniques. Uncertainty in the infrared thermography method measurements is estimated to be about 2-5 %. The accuracy of the method and its potential application to non-transparent materials makes it a good alternative to extend current research on anisotropic thermal transport in polymeric materials. A second IRT application allows us to investigate the dependence of heat capacity on deformation. We find that heat capacity increases with stretch ratio in polyisoprene specimens under uniaxial extension. The deviation from the equilibrium value of heat capacity is consistent with an independent set of experiments comparing anisotropy in thermal diffusivity and conductivity employing FRS and IRT techniques. We identify finite extensibility and strain

  19. Preliminary crustal deformation model deduced from GPS and earthquakes’ data at Abu-Dabbab area, Eastern Desert, Egypt

    Directory of Open Access Journals (Sweden)

    Abdel-Monem S. Mohamed

    2013-06-01

    From the seismic tomography study, the 3D Vp and Vp/Vs crustal models indicate high Vp/Vs values forms an elongated anomaly, in the central part of the study area, that extends from a depth of 12 km to about 1–2 km of depth is obtained. By using this crustal model in relocations all seismicity informed that most of the seismicity strongly tend to occur in a cluster manner exactly above the southern part of the study area. Based on the conducted source mechanism study, it is noticed that shallow earthquakes are associated by a high CLVD ratio (up to 40%. Furthermore, initiation of a high level seismic activity, without a large seismic main shock is observed in the Abu-Dabbab area. The distribution of micro-earthquakes tends to align in an ENE–WSW direction marking a zone of activity verse the Red Sea. The nucleation of the seismic activity beneath the southern part of the Abu-Dabbab crust is more consistent with the obtained crustal deformation result by increasing the crustal movement in the south part than the northern part. Then, based on the obtained results of the above mentioned studies; seismic tomography; source mechanisms, and crustal deformation we conclude that these seismic activities that are associated by crustal deformation are owing to some magma activity beneath the crust of the Abu-Dabbab area.

  20. PRELIMINARY ESTIMATION OF POSTSEISMIC DEFORMATION PARAMETERS FROM CONTINUOUS GPS DATA IN KOREA PENINSULA AND IEODO AFTER THE 2011 TOHOKU-OKI MW9.0 EARTHQUAKE

    Directory of Open Access Journals (Sweden)

    W. A. W. Aris

    2016-09-01

    Full Text Available This paper describes utilization of GPS data in Korea Peninsula and IEODO ocean research station for investigation of postseismic deformation characteristic after the 2011 Tohoku-oki Mw9.0 Earthquake. Analytical logarithmic and exponential functions were used to evaluate the postseismic deformation parameters. The results found that the data in Korea Peninsula and IEODO during periods of mid-2011 – mid-2014 are fit better using logarithmic function with deformation decay at 134.5 ±0.1 days than using the exponential function. The result also clearly indicates that further investigation into postseismic deformation over longer data span should be taken into account to explain tectonic deformation over the region.

  1. Thermal Expansion Anomaly and Spontaneous Magnetostriction of Y2Fe14Al3 Compound

    International Nuclear Information System (INIS)

    Yan-Ming, Hao; Xin-Yuan, Jiang; Chun-Jing, Gao; Yan-Zhao, Wu; Yan-Yan, Zhang

    2009-01-01

    The structure and magnetic properties of Y 2 Fe 14 Al 3 compound are investigated by means of x-ray diffraction and magnetization measurements. The Y 2 Fe 14 Al 3 compound has a hexagonal Th 2 Ni 17 -type structure. Negative thermal expansion is found in Y 2 Fe 14 Al 3 compound in the temperature range from 403 to 491K by x-ray dilatometry. The coefficient of the average thermal expansion is α-bar = –2.54 × 10 −5 K −1 . The spontaneous magnetostrictive deformations from 283 to 470K are calculated by means of the differences between the experimental values of the lattice parameters and the corresponding values extrapolated from the paramagnetic range. The result shows that the spontaneous volume magnetostrictive deformation ω S decreases from 5.74 × 10 −3 to nearly zero with temperature increasing from 283 to 470 K, the spontaneous linear magnetostrictive deformation λ c along the c-axis is larger than the spontaneous linear magnetostrictive deformation λ a in basal-plane in the same temperature below 350 K

  2. Solute grain boundary segregation during high temperature plastic deformation in a Cr-Mo low alloy steel

    International Nuclear Information System (INIS)

    Chen, X.-M.; Song, S.-H.; Weng, L.-Q.; Liu, S.-J.

    2011-01-01

    Highlights: → The segregation of P and Mo is evidently enhanced by plastic deformation. → The boundary concentrations of P and Mo increase with increasing strain. → A model with consideration of site competition in grain boundary segregation in a ternary system is developed. → Model predictions show a reasonable agreement with the observations. - Abstract: Grain boundary segregation of Cr, Mo and P to austenite grain boundaries in a P-doped 1Cr0.5Mo steel is examined using field emission gun scanning transmission electron microscopy for the specimens undeformed and deformed by 10% with a strain rate of 2 x 10 -3 s -1 at 900 deg. C, and subsequently water quenched to room temperature. Before deformation, there is some segregation for Mo and P, but the segregation is considerably increased after deformation. The segregation of Cr is very small and there is no apparent difference between the undeformed and deformed specimens. Since the thermal equilibrium segregation has been attained prior to deformation, the segregation produced during deformation has a non-equilibrium characteristic. A theoretical model with consideration of site competition in grain boundary segregation between two solutes in a ternary alloy is developed to explain the experimental results. Model predictions are made, which show a reasonable agreement with the observations.

  3. Thermal Molding of Organic Thin-Film Transistor Arrays on Curved Surfaces.

    Science.gov (United States)

    Sakai, Masatoshi; Watanabe, Kento; Ishimine, Hiroto; Okada, Yugo; Yamauchi, Hiroshi; Sadamitsu, Yuichi; Kudo, Kazuhiro

    2017-12-01

    In this work, a thermal molding technique is proposed for the fabrication of plastic electronics on curved surfaces, enabling the preparation of plastic films with freely designed shapes. The induced strain distribution observed in poly(ethylene naphthalate) films when planar sheets were deformed into hemispherical surfaces clearly indicated that natural thermal contraction played an important role in the formation of the curved surface. A fingertip-shaped organic thin-film transistor array molded from a real human finger was fabricated, and slight deformation induced by touching an object was detected from the drain current response. This type of device will lead to the development of robot fingers equipped with a sensitive tactile sense for precision work such as palpation or surgery.

  4. A study on an efficient prediction of welding deformation for T-joint laser welding of sandwich panel PART I : Proposal of a heat source model

    Directory of Open Access Journals (Sweden)

    Jae Woong Kim

    2013-09-01

    Full Text Available The use of I-Core sandwich panel has increased in cruise ship deck structure since it can provide similar bending strength with conventional stiffened plate while keeping lighter weight and lower web height. However, due to its thin plate thickness, i.e. about 4~6 mm at most, it is assembled by high power CO2 laser welding to minimize the welding deformation. This research proposes a volumetric heat source model for T-joint of the I-Core sandwich panel and a method to use shell element model for a thermal elasto-plastic analysis to predict welding deformation. This paper, Part I, focuses on the heat source model. A circular cone type heat source model is newly suggested in heat transfer analysis to realize similar melting zone with that observed in experiment. An additional suggestion is made to consider negative defocus, which is commonly applied in T-joint laser welding since it can provide deeper penetration than zero defocus. The proposed heat source is also verified through 3D thermal elasto-plastic analysis to compare welding deformation with experimental results. A parametric study for different welding speeds, defocus values, and welding powers is performed to investigate the effect on the melting zone and welding deformation. In Part II, focuses on the proposed method to employ shell element model to predict welding deformation in thermal elasto-plastic analysis instead of solid element model.

  5. Non-Deforming, High-Reflectance X-ray Coatings for Lynx and Other Future Missions

    Science.gov (United States)

    Windt, David

    The overarching challenge addressed by this proposal is the development of highreflectance, high-resolution X-ray mirrors, to be used for the construction of lightweight X-ray telescopes for future NASA astronomy missions such as Lynx and others. The proposal's two specific aims are: 1) the development of optimized iridium-based interference coatings for the 0.1–10 keV band; and 2) the development of methods to mitigate coating-stress-induced substrate deformations in thin-shell glass and Si mirror segments. These goals will be achieved by building on established film deposition techniques and metrology infrastructure for X-ray optics that have been developed and advanced by the PI through APRA funding since 1999. Specific Aim #1: Interference Coatings for the 0.1–10 keV Energy Band Telescope effective area can be maximized by using Ir-based reflective coatings that exploit optical interference to provide higher reflectance than Ir alone. However, only preliminary investigations of such coatings have been conducted thus far; more research is required to fully optimize these coatings for maximum performance, to experimentally determine the coating designs that are feasible, and to determine the achievable X-ray reflectance, film stress, surface roughness, and thermal and temporal stability. The first specific aim of this proposal is to reach these very goals through a comprehensive research program. Demonstration of the achievable reflectance, stress, and roughness in stable, optimized coatings will in turn facilitate global telescope design optimization, by identifying the best coating for each mirror shell based on incidence angle, and on telescope effective-area and field-of-view requirements. The research has the potential to greatly increase the effective area of future X-ray telescopes. Specific Aim #2: Mitigation of Coating-Stress-Induced Substrate Deformations High-quality films of Ir and other candidate materials (e.g., B4C) to be investigated for the 0

  6. The effect of mechanical restraint on the deformation of Zircaloy cladding

    International Nuclear Information System (INIS)

    Jones, P.M.; Haste, T.J.

    1980-10-01

    Zircaloy cladding, deformed at temperatures postulated for loss-of-coolant accidents, can exhibit considerable ductility. The actual circumferential strain is governed by the temperature uniformity around the rod during the time at which the major part of the deformation occurs. If the bulges in neighbouring rods in a multi-rod array touch before rupture, and the array is large enough for the outer rods to restrain bulges rather than be pushed away by them, then the stress in such bulges drops. However the stress in adjacent axial regions of the cladding which have not contacted remains high and these continue to strain until they also interact, thus propagating the bulging axially. Meanwhile the non-contacted portions of the interacting bulges continue to strain slowly into the remaining sub-channels. Illustrative calculations suggest that the mechanical restraint of bulging cladding will only be effective in increasing sub-channel blockage when the failure strains are greater than 60-70%. This may occur with temperature differences between neighbouring rods of 10-25 0 C if the deformation process is thermally stabilised. (author)

  7. Thermal instability in a stratified plasma

    International Nuclear Information System (INIS)

    Hermanns, D.F.M.; Priest, E.R.

    1989-01-01

    The thermal instability mechansism has been studied in connection to observed coronal features, like, e.g. prominences or cool cores in loops. Although these features show a lot of structure, most studies concern the thermal instability in an uniform medium. In this paper, we investigate the thermal instability and the interaction between thermal modes and the slow magneto-acoustic subspectrum for a stratified plasma slab. We fomulate the relevant system of equations and give some straightforward properties of the linear spectrum of a non-uniform plasma slab, i.e. the existence of continuous parts in the spectrum. We present a numerical scheme with which we can investigate the linear spectrum for equilibrium states with stratification. The slow and thermal subspectra of a crude coronal model are given as a preliminary result. (author). 6 refs.; 1 fig

  8. Actuators of 3-element unimorph deformable mirror

    Science.gov (United States)

    Fu, Tianyang; Ning, Yu; Du, Shaojun

    2016-10-01

    Kinds of wavefront aberrations exist among optical systems because of atmosphere disturbance, device displacement and a variety of thermal effects, which disturb the information of transmitting beam and restrain its energy. Deformable mirror(DM) is designed to adjust these wavefront aberrations. Bimorph DM becomes more popular and more applicable among adaptive optical(AO) systems with advantages in simple structure, low cost and flexible design compared to traditional discrete driving DM. The defocus aberration accounted for a large proportion of all wavefront aberrations, with a simpler surface and larger amplitude than others, so it is very useful to correct the defocus aberration effectively for beam controlling and aberration adjusting of AO system. In this study, we desired on correcting the 3rd and 10th Zernike modes, analyze the characteristic of the 3rd and 10th defocus aberration surface distribution, design 3-element actuators unimorph DM model study on its structure and deformation principle theoretically, design finite element models of different electrode configuration with different ring diameters, analyze and compare effects of different electrode configuration and different fixing mode to DM deformation capacity through COMSOL finite element software, compare fitting efficiency of DM models to the 3rd and 10th Zernike modes. We choose the inhomogeneous electrode distribution model with better result, get the influence function of every electrode and the voltage-PV relationship of the model. This unimorph DM is suitable for the AO system with a mainly defocus aberration.

  9. Shape memory effects, thermal expansion and B19' martensite texture in titanium nickelide

    International Nuclear Information System (INIS)

    Zel'dovich, V.I.; Sobyanina, G.A.; Rinkevich, O.S.; Gundyrev, V.M.

    1996-01-01

    The influence of plastic deformation by tension and cold rolling on shape memory effect, reverse shape memory effect, thermal expansion and texture state of martensite in titanium nickelide is under study. The relationship of thermal expansion coefficient to the value of strain during direct and reverse shape memory effect is established

  10. Research on the drawing process with a large total deformation wires of AZ31 alloy

    International Nuclear Information System (INIS)

    Bajor, T; Muskalski, Z; Suliga, M

    2010-01-01

    Magnesium and their alloys have been extensively studied in recent years, not only because of their potential applications as light-weight engineering materials, but also owing to their biodegradability. Due to their hexagonal close-packed crystallographic structure, cold plastic processing of magnesium alloys is difficult. The preliminary researches carried out by the authors have indicated that the application of the KOBO method, based on the effect of cyclic strain path change, for the deformation of magnesium alloys, provides the possibility of obtaining a fine-grained structure material to be used for further cold plastic processing with large total deformation. The main purpose of this work is to present research findings concerning a detailed analysis of mechanical properties and changes occurring in the structure of AZ31 alloy wire during the multistage cold drawing process. The appropriate selection of drawing parameters and the application of multistep heat treatment operations enable the deformation of the AZ31 alloy in the cold drawing process with a total draft of about 90%.

  11. Basic thermal-mechanical properties and thermal shock, fatigue resistance of swaged + rolled potassium doped tungsten

    Science.gov (United States)

    Zhang, Xiaoxin; Yan, Qingzhi; Lang, Shaoting; Xia, Min; Ge, Changchun

    2014-09-01

    The potassium doped tungsten (W-K) grade was achieved via swaging + rolling process. The swaged + rolled W-K alloy exhibited acceptable thermal conductivity of 159.1 W/m K and ductile-to-brittle transition temperature of about 873 K while inferior mechanical properties attributed to the coarse pores and small deformation degree. Then the thermal shock, fatigue resistance of the W-K grade were characterized by an electron beam facility. Thermal shock tests were conducted at absorbed power densities varied from 0.22 to 1.1 GW/m2 in a step of 0.22 GW/m2. The cracking threshold was in the range of 0.44-0.66 GW/m2. Furthermore, recrystallization occurred in the subsurface of the specimens tested at 0.66-1.1 GW/m2 basing on the analysis of microhardness and microstructure. Thermal fatigue tests were performed at 0.44 GW/m2 up to 1000 cycles and no cracks emerged throughout the tests. Moreover, recrystallization occurred after 1000 cycles.

  12. Thermal Management Tools for Propulsion System Trade Studies and Analysis

    Science.gov (United States)

    McCarthy, Kevin; Hodge, Ernie

    2011-01-01

    Energy-related subsystems in modern aircraft are more tightly coupled with less design margin. These subsystems include thermal management subsystems, vehicle electric power generation and distribution, aircraft engines, and flight control. Tighter coupling, lower design margins, and higher system complexity all make preliminary trade studies difficult. A suite of thermal management analysis tools has been developed to facilitate trade studies during preliminary design of air-vehicle propulsion systems. Simulink blocksets (from MathWorks) for developing quasi-steady-state and transient system models of aircraft thermal management systems and related energy systems have been developed. These blocksets extend the Simulink modeling environment in the thermal sciences and aircraft systems disciplines. The blocksets include blocks for modeling aircraft system heat loads, heat exchangers, pumps, reservoirs, fuel tanks, and other components at varying levels of model fidelity. The blocksets have been applied in a first-principles, physics-based modeling and simulation architecture for rapid prototyping of aircraft thermal management and related systems. They have been applied in representative modern aircraft thermal management system studies. The modeling and simulation architecture has also been used to conduct trade studies in a vehicle level model that incorporates coupling effects among the aircraft mission, engine cycle, fuel, and multi-phase heat-transfer materials.

  13. Evaluation of thermal effects on the beam quality of disk laser with unstable resonator

    Science.gov (United States)

    Shayganmanesh, Mahdi; Beirami, Reza

    2017-01-01

    In this paper thermal effects of the disk active medium and associated effects on the beam quality of laser are investigated. Using Collins integral and iterative method, transverse mode of an unstable resonator including a Yb:YAG active medium in disk geometry is calculated. After that the beam quality of the laser is calculated based on the generalized beam characterization method. Thermal lensing of the disk is calculated based on the OPD (Optical Path Difference) concept. Five factors influencing the OPD including temperature gradient, disk thermal expansion, photo-elastic effect, electronic lens and disk deformation are considered in our calculations. The calculations show that the effect of disk deformation factor on the quality of laser beam in the resonator is strong. However the total effect of all the thermal factors on the internal beam quality is fewer. Also it is shown that thermal effects degrade the output power, beam profile and beam quality of the output laser beam severely. As well the magnitude of each of affecting factors is evaluated distinctly.

  14. Relaxation of residual stress in MMC after combined plastic deformation and heat treatment

    International Nuclear Information System (INIS)

    Bruno, G.; Ceretti, M.; Girardin, E.; Giuliani, A.; Manescu, A.

    2004-01-01

    Neutron Diffraction shows that plastic pre-deformation and heat treatments have opposite effects on the residual stress in Al-SiC p composites. The thermal micro residual stress is relaxed or even reversed by pre-strains above 0.2%, but restored by heat treatments. The sense of relaxation changes above 400 deg. C (the mixing temperature)

  15. Preliminary design study for a carbide LEU-nuclear thermal rocket

    International Nuclear Information System (INIS)

    Venneri, P.F.; Kim, Y.

    2014-01-01

    Nuclear space propulsion is a requirement for the successful exploration of the solar system. It offers the possibility of having both a high specific impulse and a relatively high thrust, allowing rapid transit times with a minimum usage of fuel. This paper proposes a nuclear thermal rocket design based on heritage NERVA rockets that makes use of Low Enriched Uranium (LEU) fuel. The Carbide LEU Nuclear Thermal Rocket (C-LEU-NTR) is designed to fulfill the rocket requirements as set forth in the NASA 2009 Mars Mission Design Reference Architecture 5.0, that is provide 25,000 lbf of thrust, operate at full power condition for at least two hours, and have a specific impulse close to 900 s. The neutronics analysis was done using MCNP5 with the ENDF/B-VII.1 neutron library. The thermal hydraulic calculations and size optimization were completed with a finite difference code being developed at the Center for Space Nuclear Research. (authors)

  16. The impact of patient self assessment of deformity on HRQL in adults with scoliosis

    Directory of Open Access Journals (Sweden)

    Moss Nathan D

    2007-10-01

    Full Text Available Abstract Background Body image and HRQL are significant issues for patients with scoliosis due to cosmetic deformity, physical and psychological symptoms, and treatment factors. A selective review of scoliosis literature revealed that self report measures of body image and HRQL share unreliable correlations with radiographic measures and clinician recommendations for surgery. However, current body image and HRQL measures do not indicate which aspects of scoliosis deformity are the most distressing for patients. The WRVAS is an instrument designed to evaluate patient self assessment of deformity, and may show some promise in identifying aspects of deformity most troubling to patients. Previous research on adolescents with scoliosis supports the use of the WRVAS as a clinical tool, as the instrument shares strong correlations with radiographic measures and quality of life instruments. There has been limited use of this instrument on adult populations. Methods The WRVAS and the SF-36v2, a HRQL measure, were administered to 71 adults with scoliosis, along with a form to report age and gender. Preliminary validation analyses were performed on the WRVAS (floor and ceiling effects, internal consistency and collinearity, correlations with the SF-36v2, and multiple regression with the WRVAS total score as the predictor, and SF-36v2 scores as outcomes. Results The psychometric properties of the WRVAS were acceptable. Older participants perceived their deformities as more severe than younger participants. More severe deformities were associated with lower scores on the Physical Component Summary Score of the SF-36v2. Total WRVAS score also predicted Physical Component Summary scores. Conclusion The results of the current study indicate that the WRVAS is a reliable tool to use with adult patients, and that patient self assessment of deformity shared a relationship with physical rather than psychological aspects of HRQL. The current and previous studies

  17. A miniature concentrating photovoltaic and thermal system

    International Nuclear Information System (INIS)

    Kribus, Abraham; Kaftori, Daniel; Mittelman, Gur; Hirshfeld, Amir; Flitsanov, Yuri; Dayan, Abraham

    2006-01-01

    A novel miniature concentrating PV (MCPV) system is presented and analyzed. The system is producing both electrical and thermal energy, which is supplied to a nearby consumer. In contrast to PV/thermal (PV/T) flat collectors, the heat from an MCPV collector is not limited to low-temperature applications. The work reported here refers to the evaluation and preliminary design of the MCPV approach. The heat transport system, the electric and thermal performance, the manufacturing cost, and the resulting cost of energy in case of domestic water heating have been analyzed. The results show that the new approach has promising prospects

  18. Evaluation of high temperature superconductive thermal bridges for space borne cryogenic detectors

    Science.gov (United States)

    Scott, Elaine P.

    1996-01-01

    Infrared sensor satellites are used to monitor the conditions in the earth's upper atmosphere. In these systems, the electronic links connecting the cryogenically cooled infrared detectors to the significantly warmer amplification electronics act as thermal bridges and, consequently, the mission lifetimes of the satellites are limited due to cryogenic evaporation. High-temperature superconductor (HTS) materials have been proposed by researchers at the National Aeronautics and Space Administration Langley's Research Center (NASA-LaRC) as an alternative to the currently used manganin wires for electrical connection. The potential for using HTS films as thermal bridges has provided the motivation for the design and the analysis of a spaceflight experiment to evaluate the performance of this superconductive technology in the space environment. The initial efforts were focused on the preliminary design of the experimental system which allows for the quantitative comparison of superconductive leads with manganin leads, and on the thermal conduction modeling of the proposed system. Most of the HTS materials were indicated to be potential replacements for the manganin wires. In the continuation of this multi-year research, the objectives of this study were to evaluate the sources of heat transfer on the thermal bridges that have been neglected in the preliminary conductive model and then to develop a methodology for the estimation of the thermal conductivities of the HTS thermal bridges in space. The Joule heating created by the electrical current through the manganin wires was incorporated as a volumetric heat source into the manganin conductive model. The radiative heat source on the HTS thermal bridges was determined by performing a separate radiant interchange analysis within a high-T(sub c) superconductor housing area. Both heat sources indicated no significant contribution on the cryogenic heat load, which validates the results obtained in the preliminary conduction

  19. Thermal processing system concepts and considerations for RWMC buried waste

    International Nuclear Information System (INIS)

    Eddy, T.L.; Kong, P.C.; Raivo, B.D.; Anderson, G.L.

    1992-02-01

    This report presents a preliminary determination of ex situ thermal processing system concepts and related processing considerations for application to remediation of transuranic (TRU)-contaminated buried wastes (TRUW) at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Beginning with top-level thermal treatment concepts and requirements identified in a previous Preliminary Systems Design Study (SDS), a more detailed consideration of the waste materials thermal processing problem is provided. Anticipated waste stream elements and problem characteristics are identified and considered. Final waste form performance criteria, requirements, and options are examined within the context of providing a high-integrity, low-leachability glass/ceramic, final waste form material. Thermal processing conditions required and capability of key systems components (equipment) to provide these material process conditions are considered. Information from closely related companion study reports on melter technology development needs assessment and INEL Iron-Enriched Basalt (IEB) research are considered. Five potentially practicable thermal process system design configuration concepts are defined and compared. A scenario for thermal processing of a mixed waste and soils stream with essentially no complex presorting and using a series process of incineration and high temperature melting is recommended. Recommendations for applied research and development necessary to further detail and demonstrate the final waste form, required thermal processes, and melter process equipment are provided

  20. Thermal processing system concepts and considerations for RWMC buried waste

    Energy Technology Data Exchange (ETDEWEB)

    Eddy, T.L.; Kong, P.C.; Raivo, B.D.; Anderson, G.L.

    1992-02-01

    This report presents a preliminary determination of ex situ thermal processing system concepts and related processing considerations for application to remediation of transuranic (TRU)-contaminated buried wastes (TRUW) at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Beginning with top-level thermal treatment concepts and requirements identified in a previous Preliminary Systems Design Study (SDS), a more detailed consideration of the waste materials thermal processing problem is provided. Anticipated waste stream elements and problem characteristics are identified and considered. Final waste form performance criteria, requirements, and options are examined within the context of providing a high-integrity, low-leachability glass/ceramic, final waste form material. Thermal processing conditions required and capability of key systems components (equipment) to provide these material process conditions are considered. Information from closely related companion study reports on melter technology development needs assessment and INEL Iron-Enriched Basalt (IEB) research are considered. Five potentially practicable thermal process system design configuration concepts are defined and compared. A scenario for thermal processing of a mixed waste and soils stream with essentially no complex presorting and using a series process of incineration and high temperature melting is recommended. Recommendations for applied research and development necessary to further detail and demonstrate the final waste form, required thermal processes, and melter process equipment are provided.

  1. Vertical Deformation Monitoring of the Suspension Bridge Tower Using GNSS: A Case Study of the Forth Road Bridge in the UK

    Directory of Open Access Journals (Sweden)

    Qusen Chen

    2018-02-01

    Full Text Available The vertical deformation monitoring of a suspension bridge tower is of paramount importance to maintain the operational safety since nearly all forces are eventually transferred as the vertical stress on the tower. This paper analyses the components affecting the vertical deformation and attempts to reveal its deformation mechanism. Firstly, we designed a strategy for high-precision GNSS data processing aiming at facilitating deformation extraction and analysis. Then, 33 months of vertical deformation time series of the southern tower of the Forth Road Bridge (FRB in the UK were processed, and the accurate subsidence and the parameters of seasonal signals were estimated based on a classic function model that has been widely studied to analyse GNSS coordinate time series. We found that the subsidence rate is about 4.7 mm/year, with 0.1 mm uncertainty. Meanwhile, a 15-month meteorological dataset was utilised with a thermal expansion model (TEM to explain the effects of seasonal signals on tower deformation. The amplitude of the annual signals correlated quite well that obtained by the TEM, with the consistency reaching 98.9%, demonstrating that the thermal effect contributes significantly to the annual signals. The amplitude of daily signals displays poor consistency with the ambient temperature data. However, the phase variation tendencies between the daily signals of the vertical deformation and the ambient temperature are highly consistent after February 2016. Finally, the potential contribution of the North Atlantic Drift (NAD to the characteristics of annual and daily signals is discussed because of the special geographical location of the FRB. Meanwhile, this paper emphasizes the importance of collecting more detailed meteorological and other loading data for the investigation of the vertical deformation mechanism of the bridge towers over time with the support of GNSS.

  2. Test facilities for evaluating nuclear thermal propulsion systems

    International Nuclear Information System (INIS)

    Beck, D.F.; Allen, G.C.; Shipers, L.R.; Dobranich, D.; Ottinger, C.A.; Harmon, C.D.; Fan, W.C.; Todosow, M.

    1992-01-01

    Interagency panels evaluating nuclear thermal propulsion (NTP) development options have consistently recognized the need for constructing a major new ground test facility to support fuel element and engine testing. This paper summarizes the requirements, configuration, and baseline performance of some of the major subsystems designed to support a proposed ground test complex for evaluating nuclear thermal propulsion fuel elements and engines being developed for the Space Nuclear Thermal Propulsion (SNTP) program. Some preliminary results of evaluating this facility for use in testing other NTP concepts are also summarized

  3. Identifying deformation mechanisms in the NEEM ice core using EBSD measurements

    Science.gov (United States)

    Kuiper, Ernst-Jan; Weikusat, Ilka; Drury, Martyn R.; Pennock, Gill M.; de Winter, Matthijs D. A.

    2015-04-01

    Deformation of ice in continental sized ice sheets determines the flow behavior of ice towards the sea. Basal dislocation glide is assumed to be the dominant deformation mechanism in the creep deformation of natural ice, but non-basal glide is active as well. Knowledge of what types of deformation mechanisms are active in polar ice is critical in predicting the response of ice sheets in future warmer climates and its contribution to sea level rise, because the activity of deformation mechanisms depends critically on deformation conditions (such as temperature) as well as on the material properties (such as grain size). One of the methods to study the deformation mechanisms in natural materials is Electron Backscattered Diffraction (EBSD). We obtained ca. 50 EBSD maps of five different depths from a Greenlandic ice core (NEEM). The step size varied between 8 and 25 micron depending on the size of the deformation features. The size of the maps varied from 2000 to 10000 grid point. Indexing rates were up to 95%, partially by saving and reanalyzing the EBSP patterns. With this method we can characterize subgrain boundaries and determine the lattice rotation configurations of each individual subgrain. Combining these observations with arrangement/geometry of subgrain boundaries the dislocation types can be determined, which form these boundaries. Three main types of subgrain boundaries have been recognized in Antarctic (EDML) ice core¹². Here, we present the first results obtained from EBSD measurements performed on the NEEM ice core samples from the last glacial period, focusing on the relevance of dislocation activity of the possible slip systems. Preliminary results show that all three subgrain types, recognized in the EDML core, occur in the NEEM samples. In addition to the classical boundaries made up of basal dislocations, subgrain boundaries made of non-basal dislocations are also common. ¹Weikusat, I.; de Winter, D. A. M.; Pennock, G. M.; Hayles, M

  4. Effect of rolling deformation on the microstructure of bulk Cu60Zr20Ti20 metallic glass and its crystallization

    DEFF Research Database (Denmark)

    Cao, Q.P.; Li, J.F.; Zhou, Y.H.

    2006-01-01

    Bulk Cu60Zr20Ti20 metallic glass has been rolled at room temperature (RT) and cryogenic temperature (CIF) up to 97% in thickness reduction, and the dependences of microstructure on the strain and temperature have been investigated. It is revealed that as the deformation proceeds below a critical...... thickness reduction, which is 87% at RT and 89% at CT, only the shear band density and the free-volume content increase, whereas the thermal stability of the deformed glass remains unchanged. Deformation above the critical thickness reduction results in phase separation plus nanocrystallization at RT...

  5. Thermal Model Predictions of Advanced Stirling Radioisotope Generator Performance

    Science.gov (United States)

    Wang, Xiao-Yen J.; Fabanich, William Anthony; Schmitz, Paul C.

    2014-01-01

    This paper presents recent thermal model results of the Advanced Stirling Radioisotope Generator (ASRG). The three-dimensional (3D) ASRG thermal power model was built using the Thermal Desktop(trademark) thermal analyzer. The model was correlated with ASRG engineering unit test data and ASRG flight unit predictions from Lockheed Martin's (LM's) I-deas(trademark) TMG thermal model. The auxiliary cooling system (ACS) of the ASRG is also included in the ASRG thermal model. The ACS is designed to remove waste heat from the ASRG so that it can be used to heat spacecraft components. The performance of the ACS is reported under nominal conditions and during a Venus flyby scenario. The results for the nominal case are validated with data from Lockheed Martin. Transient thermal analysis results of ASRG for a Venus flyby with a representative trajectory are also presented. In addition, model results of an ASRG mounted on a Cassini-like spacecraft with a sunshade are presented to show a way to mitigate the high temperatures of a Venus flyby. It was predicted that the sunshade can lower the temperature of the ASRG alternator by 20 C for the representative Venus flyby trajectory. The 3D model also was modified to predict generator performance after a single Advanced Stirling Convertor failure. The geometry of the Microtherm HT insulation block on the outboard side was modified to match deformation and shrinkage observed during testing of a prototypic ASRG test fixture by LM. Test conditions and test data were used to correlate the model by adjusting the thermal conductivity of the deformed insulation to match the post-heat-dump steady state temperatures. Results for these conditions showed that the performance of the still-functioning inboard ACS was unaffected.

  6. Development of a Rotation Drickamer Apparatus for Deformation Studies Under High Pressure and High Temperature: Applications to magnesiowustite and Wadsleyite

    Science.gov (United States)

    Xu, Y.; Karato, S.

    2002-12-01

    Well-controlled high-pressure deformation experiments are critical for understanding the dynamics of Earth's interior. Most of the previous works on ultrahigh-pressure (P>10 GPa) deformation experiments have two limitations. (1) The mode of deformation is "stress-relaxation", in which stress changes with time in a given experiment, and (2) the magnitude of stress is limited (press combined with a rotation actuator involving an ac servo-motor. After the desired pressure and temperature are reached, torsional stress can be applied to a sample with a constant rotation rate. The advantage of this design is that the direction of shear deformation is normal to that of compression and therefore compression and deformation can be separated. A sample (typically ~1.8 mm diameter and ~0.2 mm thickness) is sandwiched between two zirconia plates and two heater plates made of TiC + diamond. Thin foils of W3%Re and W25%Re are inserted between two halves of samples which act as a thermocouple as well as strain markers. We have conducted a preliminary test on MgO at ~12 GPa and ~1470 K to the strain up to ~3. Deformation experiments on wadsleyite are underway to investigate the fabric development and rheology in this mineral.

  7. Control of surface thermal scratch of strip in tandem cold rolling

    Science.gov (United States)

    Chen, Jinshan; Li, Changsheng

    2014-07-01

    The thermal scratch seriously affects the surface quality of the cold rolled stainless steel strip. Some researchers have carried out qualitative and theoretical studies in this field. However, there is currently a lack of research on effective forecast and control of thermal scratch defects in practical production, especially in tandem cold rolling. In order to establish precise mathematical model of oil film thickness in deformation zone, the lubrication in cold rolling process of SUS410L stainless steel strip is studied, and major factors affecting oil film thickness are also analyzed. According to the principle of statistics, mathematical model of critical oil film thickness in deformation zone for thermal scratch is built, with fitting and regression analytical method, and then based on temperature comparison method, the criterion for deciding thermal scratch defects is put forward. Storing and calling data through SQL Server 2010, a software on thermal scratch defects control is developed through Microsoft Visual Studio 2008 by MFC technique for stainless steel in tandem cold rolling, and then it is put into practical production. Statistics indicate that the hit rate of thermal scratch is as high as 92.38%, and the occurrence rate of thermal scratch is decreased by 89.13%. Owing to the application of the software, the rolling speed is increased by approximately 9.3%. The software developed provides an effective solution to the problem of thermal scratch defects in tandem cold rolling, and helps to promote products surface quality of stainless steel strips in practical production.

  8. Investigation of thermal fatigue of chromium-molybdenum steels, used for calcining and agglomeration constructions

    International Nuclear Information System (INIS)

    Sinyavskij, D.P.; Gorkalo, A.P.

    1979-01-01

    The technique for investigating thermal fatigue of materials is described. The data on sample stress deformed state and current temperature values are taken from the local volume of the material studied. Results of investigating thermal fatigue of the 15KhMl and 20KhMl steels are presented

  9. High temperature x-ray diffraction of zr-2.5nb during thermal cycling in vacuum

    Directory of Open Access Journals (Sweden)

    Tumanov Mikhail

    2017-01-01

    Full Text Available The cyclic thermal tests in vacuum of zirconium alloy Zr-2.5Nb in the temperature range 250-350°C is established the presence of anomalies of thermal deformation of the crystal lattice, reducing the efficiency of the fuel rods.

  10. Is nucleon deformed?

    International Nuclear Information System (INIS)

    Abbas, Afsar

    1992-01-01

    The surprising answer to this question Is nucleon deformed? is : Yes. The evidence comes from a study of the quark model of the single nucleon and when it is found in a nucleus. It turns out that many of the long standing problems of the Naive Quark Model are taken care of if the nucleon is assumed to be deformed. Only one value of the parameter P D ∼1/4 (which specifies deformation) fits g A (the axial vector coupling constant) for all the semileptonic decay of baryons, the F/D ratio, the pion-nucleon-delta coupling constant fsub(πNΔ), the double delta coupling constant 1 fsub(πΔΔ), the Ml transition moment μΔN and g 1 p the spin structure function of proton 2 . All this gives strong hint that both neutron and proton are deformed. It is important to look for further signatures of this deformation. When this deformed nucleon finds itself in a nuclear medium its deformation decreases. So much that in a heavy nucleus the nucleons are actually spherical. We look into the Gamow-Teller strengths, magnetic moments and magnetic transition strengths in nuclei to study this property. (author). 15 refs

  11. Thermal cycling reliability of Cu/SnAg double-bump flip chip assemblies for 100 μm pitch applications

    Science.gov (United States)

    Son, Ho-Young; Kim, Ilho; Lee, Soon-Bok; Jung, Gi-Jo; Park, Byung-Jin; Paik, Kyung-Wook

    2009-01-01

    A thick Cu column based double-bump flip chip structure is one of the promising alternatives for fine pitch flip chip applications. In this study, the thermal cycling (T/C) reliability of Cu/SnAg double-bump flip chip assemblies was investigated, and the failure mechanism was analyzed through the correlation of T/C test and the finite element analysis (FEA) results. After 1000 thermal cycles, T/C failures occurred at some Cu/SnAg bumps located at the edge and corner of chips. Scanning acoustic microscope analysis and scanning electron microscope observations indicated that the failure site was the Cu column/Si chip interface. It was identified by a FEA where the maximum stress concentration was located during T/C. During T/C, the Al pad between the Si chip and a Cu column bump was displaced due to thermomechanical stress. Based on the low cycle fatigue model, the accumulation of equivalent plastic strain resulted in thermal fatigue deformation of the Cu column bumps and ultimately reduced the thermal cycling lifetime. The maximum equivalent plastic strains of some bumps at the chip edge increased with an increased number of thermal cycles. However, equivalent plastic strains of the inner bumps did not increase regardless of the number of thermal cycles. In addition, the z-directional normal plastic strain ɛ22 was determined to be compressive and was a dominant component causing the plastic deformation of Cu/SnAg double bumps. As the number of thermal cycles increased, normal plastic strains in the perpendicular direction to the Si chip and shear strains were accumulated on the Cu column bumps at the chip edge at low temperature region. Thus it was found that the Al pad at the Si chip/Cu column interface underwent thermal fatigue deformation by compressive normal strain and the contact loss by displacement failure of the Al pad, the main T/C failure mode of the Cu/SnAg flip chip assembly, then occurred at the Si chip/Cu column interface shear strain deformation

  12. Structural petrology of undeformed and experimentally deformed halite samples from USERDA site No. 7 and No. 9

    International Nuclear Information System (INIS)

    Callender, J.; Ingwell, T.

    1977-01-01

    Preliminary data from USERDA test holes No. 7 and No. 9 in the Salado Formation of southeastern New Mexico are presented. Cores consist primarily of halite (> 80 modal percent), clay, polyhalite, anhydrite, celestite, iron oxide, and magnesite. Macroscopic features of undeformed core include moderately tight grain boundaries, large cavities (less than or equal to 8 mm 2 ), fluid inclusions, rare intragranular dislocations, and coarse and bimodal textures. Petrographic examination reveals numerous secondary fluid inclusions of variable size, blebby halite and transected hopper crystals, all of which suggest mobility and recrystallization of the primary evaporite assemblages. Deformed core shows a complex group of fabric elements, including tight grain boundaries, intercrystalline lattice rotation, cavity deformation and closure, distortion of hopper crystals, polygonization, irregular lattice dislocations, glide dislocations, and climb dislocations. Grain boundaries become tight or locked with deformation, forming pinned and bulged grains. Intercrystalline lattice rotation causes grains to rotate as much as 17 0 to develop preferred orientation. Polygonization yields fabrics analogous to prophyroclasts in cataclastic rocks. Irregular dislocations are relatively abundant. Glide dislocations are also abundant in many deformed specimens. Individual mineral components within deformed halite also exhibit deformational fabrics. Folded layers of clay and anhydrite, and bent and broken single crystals of anhydrite are present in some samples. Secondary fluid inclusions apparently migrate in response to differential stress and form along dislocations in halite, healing the dislocations by secondary crystallization and forming discontinuous or completely healed dislocation fabrics. 67 figures, 9 tables

  13. Thermal and active fluctuations of a compressible bilayer vesicle

    Science.gov (United States)

    Sachin Krishnan, T. V.; Yasuda, Kento; Okamoto, Ryuichi; Komura, Shigeyuki

    2018-05-01

    We discuss thermal and active fluctuations of a compressible bilayer vesicle by using the results of hydrodynamic theory for vesicles. Coupled Langevin equations for the membrane deformation and the density fields are employed to calculate the power spectral density matrix of membrane fluctuations. Thermal contribution is obtained by means of the fluctuation dissipation theorem, whereas active contribution is calculated from exponentially decaying time correlation functions of active random forces. We obtain the total power spectral density as a sum of thermal and active contributions. An apparent response function is further calculated in order to compare with the recent microrheology experiment on red blood cells. An enhanced response is predicted in the low-frequency regime for non-thermal active fluctuations.

  14. On the design of thermally loaded fiber optics feedthroughs

    Directory of Open Access Journals (Sweden)

    Marinković Dragan Z.

    2016-01-01

    Full Text Available Thermo-mechanical design aspects of various structures exposed to cyclic thermal loading have a crucial impact on their lifetime. This is particularly valid for fiber optics feedthroughs that involve several materials with significantly different thermal expansion ratios. Thermal loading in such structures may give rise to non-trivial thermally induced deformations and therewith stresses, which can be adequately predicted and assessed only by a detailed 3-D numerical simulation. This paper considers a couple of design solutions of fiber optics feedthroughs, which have exhibited certain weaknesses in their application. Numerical simulation by means of the finite element method has been conducted to reveal the weak points of the design.

  15. Thermomechanical controls on magma supply and volcanic deformation: application to Aira caldera, Japan

    Science.gov (United States)

    Hickey, James; Gottsmann, Joachim; Nakamichi, Haruhisa; Iguchi, Masato

    2016-01-01

    Ground deformation often precedes volcanic eruptions, and results from complex interactions between source processes and the thermomechanical behaviour of surrounding rocks. Previous models aiming to constrain source processes were unable to include realistic mechanical and thermal rock properties, and the role of thermomechanical heterogeneity in magma accumulation was unclear. Here we show how spatio-temporal deformation and magma reservoir evolution are fundamentally controlled by three-dimensional thermomechanical heterogeneity. Using the example of continued inflation at Aira caldera, Japan, we demonstrate that magma is accumulating faster than it can be erupted, and the current uplift is approaching the level inferred prior to the violent 1914 Plinian eruption. Magma storage conditions coincide with estimates for the caldera-forming reservoir ~29,000 years ago, and the inferred magma supply rate indicates a ~130-year timeframe to amass enough magma to feed a future 1914-sized eruption. These new inferences are important for eruption forecasting and risk mitigation, and have significant implications for the interpretations of volcanic deformation worldwide. PMID:27619897

  16. Thermomechanical controls on magma supply and volcanic deformation: application to Aira caldera, Japan.

    Science.gov (United States)

    Hickey, James; Gottsmann, Joachim; Nakamichi, Haruhisa; Iguchi, Masato

    2016-09-13

    Ground deformation often precedes volcanic eruptions, and results from complex interactions between source processes and the thermomechanical behaviour of surrounding rocks. Previous models aiming to constrain source processes were unable to include realistic mechanical and thermal rock properties, and the role of thermomechanical heterogeneity in magma accumulation was unclear. Here we show how spatio-temporal deformation and magma reservoir evolution are fundamentally controlled by three-dimensional thermomechanical heterogeneity. Using the example of continued inflation at Aira caldera, Japan, we demonstrate that magma is accumulating faster than it can be erupted, and the current uplift is approaching the level inferred prior to the violent 1914 Plinian eruption. Magma storage conditions coincide with estimates for the caldera-forming reservoir ~29,000 years ago, and the inferred magma supply rate indicates a ~130-year timeframe to amass enough magma to feed a future 1914-sized eruption. These new inferences are important for eruption forecasting and risk mitigation, and have significant implications for the interpretations of volcanic deformation worldwide.

  17. Status of Preliminary Design on the Assembly Tools for ITER Tokamak Machine

    International Nuclear Information System (INIS)

    Nam, Kyoung O; Park, Hyun Ki; Kim, Dong Jin; Moon, Jae Hwan; Kim, Byung Seok; Lee, Jae Hyuk; Shaw, Robert

    2012-01-01

    The ITER Tokamak device is principally composed of nine 40 .deg. sectors. Each 40 .deg. sector is made up of one 40 .deg. vacuum vessel (VV), two 20 .deg. toroidal filed coils (TFC) and associated vacuum vessel thermal shield (VVTS) segments which consist of one inboard and two outboard vacuum vessel thermal shields. Based on the design description document and final report prepared by the ITER organization (IO) and conceptual design, Korea has carried out the preliminary design of these assembly tools. The assembly strategy and relevant tools for the 40 .deg. sector sub-assembly and sector assembly at in-pit should be developed to satisfy the basic assembly requirements of the ITER Tokamak machine. Assembly strategy, preliminary design of the sector sub-assembly and assembly tools are described in this paper

  18. Thermal simulation of the magnesium thermal of metallic uranium reduction

    International Nuclear Information System (INIS)

    Borges, W.A.; Saliba-Silva, A.M.

    2008-01-01

    Metallic uranium production is vital to fabricate fuel elements for nuclear research reactors and to produce radioisotopes and radiopharmaceuticals. Metallic uranium is got via magnesiothermal reduction of UF 4 . This reaction is carried out inside a closed graphite crucible inserted in a metallic reactor adequately sealed without any outside contact. The assembled set is gradually heated up inside a pit furnace up to reach the reaction ignition temperature (between 600-650 deg C). The optimization of the reactive system depends on the mathematical modeling using simulation by finite elements and computational calculation with specialized programs. In this way, the reactants' thermal behavior is forecast until they reach the ignition temperature. The optimization of the uranium production reaction is based on minimization of thermal losses using better the exo thermal reaction heat. As lower the thermal losses, as higher would be the heat amount to raise the temperature of reaction products. This promotes the adequate melting of uranium and slag, so allowing better metal/slag separation with higher metallic yield. This work shows how the mathematical simulation is made and supplies some preliminary results. (author)

  19. New technologies and new performances of the JCMT radio-telescope: a preliminary design study

    Science.gov (United States)

    Mian, S.; De Lorenzi, S.; Ghedin, L.; Rampini, F.; Marchiori, G.; Craig, S.

    2012-09-01

    With a diameter of 15m the James Clerk Maxwell Telescope (JCMT) is the largest astronomical telescope in the world designed specifically to operate in the submillimeter wavelength region of the spectrum. It is situated close to the summit of Mauna Kea, Hawaii, at an altitude of 4092m. Its primary reflector currently consists of a steel geodesic supporting structure and pressed aluminium panels on a passive mount. The major issues of the present reflector are its thermal stability and its panels deterioration. A preliminary design study for the replacement of the JCMT antenna dish is here presented. The requested shape error for the new reflector is <20μm RMS. The proposed solution is based on a semi-monocoque backing structure made of CFRP and on high precision electroformed panels. The choice of CFRP for the backing structure allows indeed to improve the antenna performance in terms of both stiffness and thermal stability, so that the required surface accuracy of the primary can be achieved even by adopting a passive panels system. Moreover thanks to CFRP, a considerable weight reduction of the elevation structure can be attained. The performance of the proposed solution for the JCMT antenna has been investigated through FE analyses and the assessed deformation of the structure under different loading cases has been taken into account for subsequent error budgeting. Results show that the proposed solution is in line with the requested performance. With this new backing structure, the JCMT would have the largest CFRP reflector ever built.

  20. Analysis of the ballooning deformation of an internally pressurized thin-wall tube during fast thermal transients

    International Nuclear Information System (INIS)

    Lin, E.I.H.

    1977-01-01

    A large-strain, time-dependent thermoplastic analysis of ballooning deformation was developed. The true (or lagorithmic) strains, the Von Mises yield criterion and Prandtl-Reuss flow rules were used. The constitutive equation was expressed in terms of the temperature, effective stress, strain and strain rate. Material isotropy was assumed as a first approximation; note that at high temperatures even zircaloy tends to lose a substantial amount of its low-temperature anisotropy. The axisymmetry of ballooning was also assumed, which has actually been verified by numerous experiments to be accurate throughout the course of ballooning, except in the final stage when rupture is imminent. The thin-shell approximation was made, which proved to be adequate for the standard fuel claddings and which was advantageous in that the averaged state of stress was rendered determinate. The analysis led to a set of non-linear ordinary differential equations, which was then integrated by a fifth-order Runge-Kutta routine. The general formulation allows for a direct interpretation of the experimentally-observed effects of the heating rate and cladding axial constraints on the ballooning behavior. Its implications on the flow-blockage and cladding-rupture evaluations were discussed. The analysis was applied to zircaloy claddings subjected to simulated thermal transient conditions. Most of the required material properties were taken from the existing uniaxial tensile test data. Analyses were performed at a uniform heating rate of 115 0 C/sec with internal pressures ranging from 100 to 1200 psi. Satisfactory agreement was obtained between the predictions and the diametral strain-time data available from tube-burst tests

  1. Low-energy E1 transitions and octupole softness in odd-A deformed nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hagemann, G B [Niels Bohr Inst., Copenhagen (Denmark); Hamamoto, I [Lund Univ. (Sweden). Dept. of Mathematical Physics; Kownacki, J; Satula, W [Warsaw Univ. (Poland)

    1992-08-01

    It is found that B(E1) values for yrast spectroscopy of deformed odd-A rare-earth nuclei calculated by using a model in which one quasiparticle is coupled to a rotor are more than an order of magnitude too small. Therefore, measured B(E1) values for {sup 169}Lu were analyzed by introducing parameters which effectively took octupole softness into account. Some preliminary results of the theoretical analysis which are presented in this paper still give do not agree completely with experiment. 4 refs., 1 tab., 5 figs.

  2. Molecular dynamics simulation on double-elastic deformation of zigzag graphene nanoribbons at low temperature

    International Nuclear Information System (INIS)

    Sun, Y.J.; Huang, Y.H.; Ma, F.; Ma, D.Y.; Hu, T.W.; Xu, K.W.

    2014-01-01

    Highlights: • Molecular dynamics simulation was performed to study the deformation behaviors of Zigzag Graphene Nano-Ribbons (ZGNRs). • The “phase transformation” from hexagonal to quasi-rectangular and the subsequent second elastic deformation were observed. • Related thermal effects model was built to predict fracture strain of ZGNRs, and was consistent with simulation results. -- Abstract: Molecular dynamics simulation was performed to study the deformation behaviors of Zigzag Graphene Nano-Ribbons (ZGNRs) 150 Å × 150 Å in size, and double-elastic deformation was observed at temperatures lower than 90 K. Essentially, at such a low temperature, the lattice vibration was significantly weakened and thus the lifetime of C-C bonds was prolonged considerably. Moreover, it was difficult for broken bonds to accumulate and resulted in the destructive fracture of ZGNRs at low temperature. As a result, the “phase transformation” from hexagonal to quasi-rectangular and subsequently the second elastic deformation took place. However, at higher temperatures, says, 300 K, brittle fracture was observed and the fracture strength decreased with temperature, which was consistent with previously reported results. Additionally at higher strain rate, the atoms could not respond to the external loading in time, the fracture strain and fracture strength were enhanced

  3. ESTIMATION OF PHASE DELAY DUE TO PRECIPITABLE WATER FOR DINSARBASED LAND DEFORMATION MONITORING

    Directory of Open Access Journals (Sweden)

    J. Susaki

    2017-09-01

    Full Text Available In this paper, we present a method for using the estimated precipitable water (PW to mitigate atmospheric phase delay in order to improve the accuracy of land-deformation assessment with differential interferometric synthetic aperture radar (DInSAR. The phase difference obtained from multi-temporal synthetic aperture radar images contains errors of several types, and the atmospheric phase delay can be an obstacle to estimating surface subsidence. In this study, we calculate PW from external meteorological data. Firstly, we interpolate the data with regard to their spatial and temporal resolutions. Then, assuming a range direction between a target pixel and the sensor, we derive the cumulative amount of differential PW at the height of the slant range vector at pixels along that direction. The atmospheric phase delay of each interferogram is acquired by taking a residual after a preliminary determination of the linear deformation velocity and digital elevation model (DEM error, and by applying high-pass temporal and low-pass spatial filters. Next, we estimate a regression model that connects the cumulative amount of PW and the atmospheric phase delay. Finally, we subtract the contribution of the atmospheric phase delay from the phase difference of the interferogram, and determine the linear deformation velocity and DEM error. The experimental results show a consistent relationship between the cumulative amount of differential PW and the atmospheric phase delay. An improvement in land-deformation accuracy is observed at a point at which the deformation is relatively large. Although further investigation is necessary, we conclude at this stage that the proposed approach has the potential to improve the accuracy of the DInSAR technique.

  4. Preliminary waste acceptance requirements - Konrad repository project

    International Nuclear Information System (INIS)

    Brennecke, P.W.; Warnecke, E.H.

    1991-01-01

    In Germany, the planned Konrad repository is proposed for the disposal of all types of radioactive wastes whose thermal influence upon the host rock is negligible. The Bundesamt fuer Strahlenschutz has established Preliminary Waste Acceptance Requirements (as of April 1990) for this facility. The respective requirements were developed on the basis of the results of site-specific safety assessments. They include general requirements on the waste packages to be disposed of as well as more specific requirements on the waste forms, the packaging and the radionuclide inventory per waste package. In addition, the delivery of waste packages was regulated. An outline of the structure and the elements of the Preliminary Waste Acceptance Requirements of April 1990 is given including comments on their legal status. (Author)

  5. FY 1999 Report on the results of technological development of machine tools for rationalization of energy utilization. Development of a lathe with high precision and conservation of energy using natural phenomenon (Thermal countermeasure using self compulsory cooling and thermal insensitive structure - results of the first year); 1999 nendo energy shiyo gorika kosaku kikai nado gijutsu kaihatsu seika hokokusho. Shizen gensho wo takumi ni oyoshita sho energy koseido senban no kaihatsu (self kyosei reikyaku to netsufukan gijutsu wo mochiita netsuhenkei yokusei taisaku - dai 1 nendo)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    A lathe, which is a central tool in a factory of automobiles or home electric appliances, tends to suffer decreased machining precision resulting from thermal deformation. This project is aimed at development of the energy-saving, high-precision lathe technologies using self compulsory cooling and thermal insensitive technologies as the countermeasures against the thermal deformation. The self compulsory cooling is a method of cooling by evaporation of water with an evaporative, water-absorptive cloth being bonded to a machine tool surface around the major axis. The thermal insensitive technologies include the three-dimensionally zero-center design technologies which help design a lathe in such a way to set the processing point (tool working point) at the base of thermal deformation in the X, Y and Z axis directions; material combination technologies to control thermal deformation; and coloring technologies to control thermal deformation. The development target is the high-precision lathe fabrication technologies, which realize a temporal precision change of 1 to 2 {mu}m or less per work dimension of 100mm. The activities cover 5 areas, including development of elementary technologies for each item and construction/evaluation of the full-size test unit. (NEDO)

  6. A feasibility study on the use of the MOOSE computational framework to simulate three-dimensional deformation of CANDU reactor fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, Kyle A., E-mail: Kyle.Gamble@inl.gov [Royal Military College of Canada, Chemistry and Chemical Engineering, 13 General Crerar Crescent, Kingston, Ontario, Canada K7K 7B4 (Canada); Williams, Anthony F., E-mail: Tony.Williams@cnl.ca [Canadian Nuclear Laboratories, Fuel and Fuel Channel Safety, 1 Plant Road, Chalk River, Ontario, Canada K0J 1J0 (Canada); Chan, Paul K., E-mail: Paul.Chan@rmc.ca [Royal Military College of Canada, Chemistry and Chemical Engineering, 13 General Crerar Crescent, Kingston, Ontario, Canada K7K 7B4 (Canada); Wowk, Diane, E-mail: Diane.Wowk@rmc.ca [Royal Military College of Canada, Mechanical and Aerospace Engineering, 13 General Crerar Crescent, Kingston, Ontario, Canada K7K 7B4 (Canada)

    2015-11-15

    Highlights: • This is the first demonstration of using the MOOSE framework for modeling CANDU fuel. • Glued and frictionless contact algorithms behave as expected for 2D and 3D cases. • MOOSE accepts and correctly interprets functions of arbitrary form. • 3D deformation calculations accurately compare against analytical solutions. • MOOSE is a viable simulation tool for modeling accident reactor conditions. - Abstract: Horizontally oriented fuel bundles, such as those in CANada Deuterium Uranium (CANDU) reactors present unique modeling challenges. After long irradiation times or during severe transients the fuel elements can laterally deform out of plane due to processes known as bow and sag. Bowing is a thermally driven process that causes the fuel elements to laterally deform when a temperature gradient develops across the diameter of the element. Sagging is a coupled mechanical and thermal process caused by deformation of the fuel pin due to creep mechanisms of the sheathing after long irradiation times and or high temperatures. These out-of-plane deformations can lead to reduced coolant flow and a reduction in coolability of the fuel bundle. In extreme cases element-to-element or element-to-pressure tube contact could occur leading to reduced coolant flow in the subchannels or pressure tube rupture leading to a loss of coolant accident. This paper evaluates the capability of the Multiphysics Object-Oriented Simulation Environment (MOOSE) framework developed at the Idaho National Laboratory to model these deformation mechanisms. The material model capabilities of MOOSE and its ability to simulate contact are also investigated.

  7. Predicting welding distortion in a panel structure with longitudinal stiffeners using inherent deformations obtained by inverse analysis method.

    Science.gov (United States)

    Liang, Wei; Murakawa, Hidekazu

    2014-01-01

    Welding-induced deformation not only negatively affects dimension accuracy but also degrades the performance of product. If welding deformation can be accurately predicted beforehand, the predictions will be helpful for finding effective methods to improve manufacturing accuracy. Till now, there are two kinds of finite element method (FEM) which can be used to simulate welding deformation. One is the thermal elastic plastic FEM and the other is elastic FEM based on inherent strain theory. The former only can be used to calculate welding deformation for small or medium scale welded structures due to the limitation of computing speed. On the other hand, the latter is an effective method to estimate the total welding distortion for large and complex welded structures even though it neglects the detailed welding process. When the elastic FEM is used to calculate the welding-induced deformation for a large structure, the inherent deformations in each typical joint should be obtained beforehand. In this paper, a new method based on inverse analysis was proposed to obtain the inherent deformations for weld joints. Through introducing the inherent deformations obtained by the proposed method into the elastic FEM based on inherent strain theory, we predicted the welding deformation of a panel structure with two longitudinal stiffeners. In addition, experiments were carried out to verify the simulation results.

  8. Measurement of full-field deformation induced by a dc electrical field in organic insulator films

    Directory of Open Access Journals (Sweden)

    Boudou L.

    2010-06-01

    Full Text Available Digital image correlation method (DIC using the correlation coefficient curve-fitting for full-field surface deformation measurements of organic insulator films is investigated in this work. First the validation of the technique was undertaken. The computer-generated speckle images and the measurement of coefficient of thermal expansion (CTE of aluminium are used to evaluate the measurement accuracy of the technique. In a second part the technique is applied to measure the mechanical deformation induced by electrical field application to organic insulators. For that Poly(ethylene naphthalene 2,6-dicarboxylate (PEN thin films were subjected to DC voltage stress and DIC provides the full-field induced deformations of the test films. The obtained results show that the DIC is a practical and robust tool for better comprehension of mechanical behaviour of the organic insulator films under electrical stress.

  9. Thermal loading study for FY 1995

    International Nuclear Information System (INIS)

    1996-01-01

    This report provides the results of sensitivity analyses designed to assist the test planners in focusing their in-situ measurements on parameters that appear to be important to waste isolation. Additionally, the study provides a preliminary assessment of the feasibility of certain thermal management options. A decision on thermal loading is a critical part of the scientific and engineering basis for evaluating regulatory compliance of the potential repository for waste isolation. To show, with reasonable assurance, that the natural and engineered barriers will perform adequately under expected repository conditions (thermally perturbed) will require an integrated approach based on thermal testing (laboratory, and in-situ), natural analog observations, and analytic modeling. The Office of Civilian Radioactive Waste Management needed input to assist in the planning of the thermal testing program. Additionally, designers required information on the viability of various thermal management concepts. An approximately 18-month Thermal Loading Study was conducted from March, 1994 until September 30, 1995 to address these issues. This report documents the findings of that study. 89 refs., 71 figs., 33 tabs

  10. Biaxial deformation behaviour of poly-ether-ether-ketone

    Science.gov (United States)

    Turner, Josh; Menary, Gary; Martin, Peter

    2018-05-01

    The biaxial tensile properties of thin poly-ether-ether-ketone (PEEK) films are presented. Investigation into the biaxial mechanical behaviour of PEEK films will provide a preliminary insight into the anticipated stress/strain response, and potential suitability, to the possible fabrication of thin walled parts through stretch blow moulding and thermoforming processes - with the multi-axial state of strain imposed onto the heated thermoplastic sheet representative of the expected strain history experienced during these material forming processes. Following identification of the prospective forming temperature window, the biaxial mechanical behaviour of the material is characterized under differing modes of deformation, at a nominal strain rate of 1 s-1. The temperature dependence is outlined within - with an appreciable increase in flow behaviour correlated with specimen temperature exceeding its glass transition temperature (Tg).

  11. Deep-seated gravitational slope deformations near the Trans-Alaska Pipeline, east-central Alaska Range, Alaska, USA

    Science.gov (United States)

    Newman, S. D.; Clague, J. J.; Rabus, B.; Stead, D.

    2013-12-01

    Multiple, active, deep-seated gravitational slope deformations (DSGSD) are present near the Trans-Alaska Pipeline and Richardson Highway in the east-central Alaska Range, Alaska, USA. We documented spatial and temporal variations in rates of surface movement of the DSGSDs between 2003 and 2011 using RADARSAT-1 and RADARSAT-2 D-InSAR images. Deformation rates exceed 10 cm/month over very large areas (>1 km2) of many rock slopes. Recent climatic change and strong seismic shaking, especially during the 2002 M 7.9 Denali Fault earthquake, appear to have exacerbated slope deformation. We also mapped DSGSD geological and morphological characteristics using field- and GIS-based methods, and constructed a conceptual 2D distinct-element numerical model of one of the DSGSDs. Preliminary results indicate that large-scale buckling or kink-band slumping may be occurring. The DSGSDs are capable of generating long-runout landslides that might impact the Trans-Alaska Pipeline and Richardson Highway. They could also block tributary valleys, thereby impounding lakes that might drain suddenly. Wrapped 24-day RADARSAT-2 descending spotlight interferogram showing deformation north of Fels Glacier. The interferogram is partially transparent and is overlaid on a 2009 WorldView-1 panchromatic image. Acquisition interval: August 2 - August 26, 2011. UTM Zone 6N.

  12. Investigation of creep deformation mechanisms at intermediate temperatures in Rene 88 DT

    International Nuclear Information System (INIS)

    Viswanathan, G.B.; Sarosi, P.M.; Henry, M.F.; Whitis, D.D.; Milligan, W.W.; Mills, M.J.

    2005-01-01

    Creep deformation substructures in the superalloy Rene 88 DT have been investigated after small-strain (0.2-0.5%) creep at 650 deg C using conventional and high resolution transmission electron microscopy. Clear differences in creep strength and deformation mechanisms have been observed as a function of applied stress and precipitate microstructure. Both coarse and fine bimodal precipitate microstructures have been tested, produced by relatively slow and fast cooling from the supersolvus solutionizing temperature. The finer γ' microstructure exhibited significantly lower creep rates. It has been established that microtwinning caused by the passage of Shockley partial dislocations on successive {1 1 1} planes is the dominant deformation process at low applied stress, and changes to shearing by 1/2[1 1 0] dislocations and Orowan looping around the larger secondary precipitates at higher applied stress. In the coarser microstructure, the dominant deformation mode is isolated faulting where 1/2[1 1 0] dislocations shear the matrix while superlattice extrinsic stacking faults are created in the secondary γ' particles. The detailed mechanisms by which these deformation modes proceed are discussed, leading to the proposition that the thermally activated process for both microtwinning and isolated faulting is similar, involving diffusion-mediated re-ordering within the γ' particles in the wake of shearing 1/6 Shockley partials. Based on the present evidence, it is proposed that the tertiary γ' volume fraction is crucial in dictating the transition in mechanism and the creep strength of these alloys

  13. Effect of the tiger stripes on the tidal deformation of Enceladus

    Science.gov (United States)

    Soucek, Ondrej; Hron, Jaroslav; Behounkova, Marie; Cadek, Ondrej

    2016-10-01

    The south polar region of Saturn's moon Enceladus has been subjected to a thorough scientific scrutiny since the Cassini mission discovery of an enigmatic system of fractures informally known as "tiger stripes". This fault system is possibly connected to the internal water ocean and exhibits a striking geological activity manifesting itself in the form of active water geysers on the moon's surface.The effect of the faults on periodic tidal deformation of the moon has so far been neglected because of the difficulties associated with the implementation of fractures in continuum mechanics models. Employing an open source finite element FEniCS package, we provide a numerical estimate of the maximum possible impact of the tiger stripes on the tidal deformation and the heat production in Enceladus's ice shell by representing the faults as narrow zones with negligible frictional and bulk resistance passing vertically through the whole shell.For a uniform ice shell thickness of 25 km, consistent with the recent estimate of libration, and for linear elastic rheology, we demonstrate that the faults can dramatically change the distribution of stress and strain in Enceladus's south polar region, leading to a significant increase of the heat flux and to a complex deformation pattern in this area. We also present preliminary results studying the effects of (i) variable ice-shell thickness, based on the recent topography, gravity and libration inversion model by Čadek et al. (2016) and (ii) Maxwell viscoelastic rheology on the global tidal deformation of the ice shell.O.S. acknowledges support by the Grant Agency of the Czech Republic through the project 15-14263Y.

  14. Effect of Thermal Mechanical Behaviors of Cu on Stress Distribution in Cu-Filled Through-Silicon Vias Under Heat Treatment

    Science.gov (United States)

    Zhao, Xuewei; Ma, Limin; Wang, Yishu; Guo, Fu

    2018-01-01

    Through-silicon vias (TSV) are facing unexpected thermo-mechanical reliability problems due to the coefficient of thermal expansion (CTE) mismatch between various materials in TSVs. During applications, thermal stresses induced by CTE mismatch will have a negative impact on other devices connecting with TSVs, even leading to failure. Therefore, it is essential to investigate the stress distribution evolution in the TSV structure under thermal loads. In this report, TSVs were heated to 450°C at different heating rates, then cooled down to room temperature after a 30-min dwelling. After heating treatment, TSV samples exhibited different Cu deformation behaviors, including Cu intrusion and protrusion. Based on the different Cu deformation behaviors, stress in Si around Cu vias of these samples was measured and analyzed. Results analyzed by Raman spectrums showed that the stress distribution changes were associated with Cu deformation behaviors. In the area near the Cu via, Cu protrusion behavior might aggravate the stress in Si obtained from the Raman measurement, while Cu intrusion might alleviate the stress. The possible reason was that in this area, the compressive stress σ_{θ } induced by thermal loads might be the dominant stress. In the area far from the Cu via, thermal loads tended to result in a tensile stress state in Si.

  15. Preliminary Study of the Onset of Nucleate Boiling (ONB) for the Thermal-hydraulic Design of HANARO Irradiation non-instrumented Capsule during the Natural Convection

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Kyungho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The HANARO reactor is an open-tank-in-pool type for easy access, and the capsules are being utilized for the irradiation test of materials and nuclear fuel in HANARO. The concept of the capsule is the direct contact with the coolant to cool the temperature of specimen down. To successfully accomplish the irradiation test, it is essential that the capsule should be designed considering the thermal margin such as the margin to Onset of Nucleate Boiling (ONB), the margin to Departure from Nucleate Boiling (DNB). In this paper, the preliminary study was performed by focusing on the ONB and the capsule design will be performed using the heat flux and temperature at ONB condition calculated in this paper. In this paper, the temperature and heat flux under ONB condition are simply calculated for the thermal design of fuel capsule for irradiation test. These values will be considered to design the non-instrumented capsule for natural circulation. To confirm the calculated value, detailed calculation will be performed using the one dimensional and multi-dimensional codes.

  16. Structural Health and Stability Assessment of High-Speed Railways via Thermal Dilation Mapping With Time-Series InSAR Analysis

    NARCIS (Netherlands)

    Qin, Xiaoqiong; Liao, Mingsheng; Zhang, L; Yang, M.

    2017-01-01

    Thermal dilation is a vital component of deformation along the extensive railway network infrastructure. To monitor subtle deformation, the synthetic aperture radar interferometry (InSAR) technique has been adopted as a space-borne geodetic tool. However, InSAR applications in railway stability

  17. A three-dimensional coupled thermo-hydro-mechanical model for deformable fractured geothermal systems

    DEFF Research Database (Denmark)

    Salimzadeh, Saeed; Paluszny, Adriana; Nick, Hamidreza M.

    2018-01-01

    A fully coupled thermal-hydraulic-mechanical (THM) finite element model is presented for fractured geothermal reservoirs. Fractures are modelled as surface discontinuities within a three-dimensional matrix. Non-isothermal flow through the rock matrix and fractures are defined and coupled to a mec......A fully coupled thermal-hydraulic-mechanical (THM) finite element model is presented for fractured geothermal reservoirs. Fractures are modelled as surface discontinuities within a three-dimensional matrix. Non-isothermal flow through the rock matrix and fractures are defined and coupled....... The model has been validated against several analytical solutions, and applied to study the effects of the deformable fractures on the injection of cold water in fractured geothermal systems. Results show that the creation of flow channelling due to the thermal volumetric contraction of the rock matrix...

  18. Plastic deformation

    NARCIS (Netherlands)

    Sitter, de L.U.

    1937-01-01

    § 1. Plastic deformation of solid matter under high confining pressures has been insufficiently studied. Jeffreys 1) devotes a few paragraphs to deformation of solid matter as a preface to his chapter on the isostasy problem. He distinguishes two properties of solid matter with regard to its

  19. Variation of mechanical and thermal properties of the thermoplastics reinforced with natural fibers by electron beam processing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sok Won [Department of Physics, University of Ulsan, Ulsan 680 749 (Korea, Republic of)], E-mail: sokkim@ulsan.ac.kr; Oh, Seungmin; Lee, Kyuse [Ilkwang Co. Ltd. 1178-6 Goyon-ri, Ungchon-mueon, Ulju-gun 689 871 (Korea, Republic of)

    2007-11-15

    With restrictions for environmental protection being strengthened, the thermoplastics reinforced with natural fibers (NFs) such as jute, kenaf, flax, etc., appeared as an automobile interior material instead of the chemical plastics. Regardless of many advantages, one shortcoming is the deformation after being formed in high temperature of about 200 deg. C, caused by the poor adhesion between the natural fibers and thermoplastics. Also, the energy saving in connection with car air-conditioning becomes very important. In this study, the thermal conductivity, tensile strength, and deformation of several kinds of thermoplastic composites composing of 50% polypropylene (PP) and 50% natural fiber irradiated by the electron beam (energy: 0.5 MeV, dose: 0-20 kGy) were measured. The length and thickness of PP and NF are 80{+-}10 mm and 40-120 {mu}m, respectively. The results show that the thermal conductivity and the tensile strength changed and became minimum when the dose of electron beam is 10 kGy, and the deformation after the thermal cycle were reduced by the electron beam.

  20. Migration of the deforming zone during seismic shear and implications for field observations, dynamic weakening, and the onset of melting

    Science.gov (United States)

    Platt, J. D.; Rice, J. R.

    2013-12-01

    Prior work in our group has shown how micron-scale strain rate localization can be explained using models for thermal pressurization and thermal decomposition in fluid-saturated gouge materials. Using parameters modeling a typical centroidal depth for a crustal seismogenic zone we predicted localized zone thicknesses in line with laboratory (Brantut et al., 2008; Kitajima et al., 2010) and field (Chester and Chester, 1998; Heermance et al., 2003; De Paola et al., 2008) observations. Further work has shown that the localized zone need not remain in a single location and may migrate across the gouge layer, in agreement with laboratory observations that show a thickening of the highly localized material with slip, and a distinct banded structure within the highly localized material (T. Mitchell, priv. comm.; Kitajima et al., 2010). We have identified two mechanisms that could cause migration. The first is a combination of thermal diffusion, hydraulic diffusion and thermal pressurization, which leads to the location of maximum pore pressure moving away from its initial position [Rice, 2006]. Since the maximum strain rate coincides with the maximum pore pressure, this causes the deforming zone to move across the gouge layer. The second mechanism is reactant depletion in a material undergoing thermal decomposition. Fluid pressurization and strain rate are slaved to the reaction, so as the reactant depletes the deforming zone will migrate towards fresh reactant. An additional symmetry breaking instability exists but is not discussed here. We have also explored how spatial variations in fault gouge properties may control the distribution of seismic shear. Since at seismic slip rates localization in a fluid-saturated material is controlled largely by pore pressure generation and hydraulic diffusion, regions that generate or trap pore pressures more efficiently will attract straining. Numerical simulations show that the deforming zone moves towards regions of low hydraulic

  1. Preliminary study of mercury target structure

    Energy Technology Data Exchange (ETDEWEB)

    Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kumasaka, Katsuyuki; Uchida, Shoji; Nakagawa, Toshi; Mori, Seiji; Nishikawa, Akira

    1997-11-01

    Development of a proton accelerator based neutron source (1.5 GeV, 5.3 mA (for neutron source 3.3 mA), thermal power 8 MW) is currently conducted by the Special Task Force for Neutron Science Initiative, JAERI. Preliminary design studies and related R and D of a solid metal target for the first stage (1.5 GeV, 1 mA) and a liquid metal target for both the first and second stages (1.5 GeV, 3.3 mA) are conducted by the Target Group to develop both solid and liquid metal target systems. A few kinds of target structures have been investigated in FY 1996 and the preliminary results for the target structures are described in this paper. Investigation results of alternative materials for the target container are also described in this paper. (author)

  2. Mechanical properties and deformation of polycrystalline lithium orthosilicate

    International Nuclear Information System (INIS)

    Bar, K.; Chu, C.Y.; Singh, J.P.; Goretta, K.C.; Routbort, J.L.; Billone, M.C.; Poeppel, R.B.

    1988-02-01

    Room-temperature strength, fracture toughness, Young's modulus, and thermal-shock resistance were determined for 68--98% dense lithium orthosilicate (Li 4 SiO 4 ) specimens. In the low-density regime, both strength and fracture toughness were controlled by the density of the specimen. At high density, the strength depends on grain size. Young's modulus values ranged from 30--103 GPa at densities between 68 and 98% TD. A critical quenching temperature difference in the range of 150--170/degree/C was observed in thermal-shock tests of bar specimens. Steady-state creep tests indicated 90% dense Li 4 SiO 4 fractures at T ≤ 800/degree/C before reaching steady state and deforms plastically at 900/degree/C. It is more creep-resistant at 900/degree/C than Li 2 O, about equal to Li 2 Zr) 3 , and less than LiA10 2 . 13 refs., 4 figs., 1 tab

  3. Thermal-hydraulics Analysis of a Radioisotope-powered Mars Hopper Propulsion System

    International Nuclear Information System (INIS)

    O'Brien, Robert C.; Klein, Andrew C.; Taitano, William T.; Gibson, Justice; Myers, Brian; Howe, Steven D.

    2011-01-01

    Thermal-hydraulics analyses results produced using a combined suite of computational design and analysis codes are presented for the preliminary design of a concept Radioisotope Thermal Rocket (RTR) propulsion system. Modeling of the transient heating and steady state temperatures of the system is presented. Simulation results for propellant blow down during impulsive operation are also presented. The results from this study validate the feasibility of a practical thermally capacitive RTR propulsion system.

  4. Deformation compensation in dynamic tomography; Compensation de deformations en tomographie dynamique

    Energy Technology Data Exchange (ETDEWEB)

    Desbat, L. [Universite Joseph Fourier, UMR CNRS 5525, 38 - Grenoble (France); Roux, S. [Universite Joseph Fourier, TIMC-IMAG, In3S, Faculte de Medecine, 38 - Grenoble (France)]|[CEA Grenoble, Lab. d' Electronique et de Technologie de l' Informatique (LETI), 38 (France); Grangeat, P. [CEA Grenoble, Lab. d' Electronique et de Technologie de l' Informatique (LETI), 38 (France)

    2005-07-01

    This work is a contribution to the compensation of motion in tomography. New classes of deformation are proposed, that compensates analytically by an algorithm of a F.B.P. type reconstruction. This work makes a generalisation of the known results for affine deformations, in parallel geometry and fan-beam, to deformation classes of infinite dimension able to include strong non linearities. (N.C.)

  5. Preliminary tests of a model of cooling-pond thermal performance

    International Nuclear Information System (INIS)

    Hicks, B.B.; Wesely, M.L.; Wilczek, J.

    1975-01-01

    Experiments performed during recent years at the cooling pond complex at the Dresden nuclear power station have been designed to improve our understanding of the fundamental properties of thermal exchange at a warm-water surface. To a considerable extent, the field studies have been successful in that they have shown that modern micrometeorological techniques can be successfully applied to the demanding circumstances of an industrial cooling lake at temperature of at least 40 0 C. The intent of these studies has been to create a set of parameterization schemes good enough to allow simulation of the performance of the Dresden cooling lake without adjustment of numerical constants. An obvious extension of these studies, and one of the goals of the cooling-pond research program as presently stated, is to obtain an accurate numerical simulation of thermal performance of ponds with use of the improved formulations that have resulted from the experimental work at the Dresden lake. The computer model is divided into two sections and can be used to test the sensitivity of predicted performance to variations in procedures for determining the thermal transfer from the surface

  6. Preliminary results from film boiling destabilisation experiments

    International Nuclear Information System (INIS)

    Naylor, P.

    1984-05-01

    A series of experiments to investigate the triggered destabilisation of film boiling has been undertaken. Film boiling was established on a polished brass rod immersed in water and the effects of various triggers were investigated. Preliminary results are presented and two thresholds have been observed: an impulse threshold below which triggered destabilisation will not occur and a thermal threshold above which film boiling will re-establish following triggered destabilisation. (author)

  7. Optimum Control for Nonlinear Dynamic Radial Deformation of Turbine Casing with Time-Varying LSSVM

    Directory of Open Access Journals (Sweden)

    Cheng-Wei Fei

    2015-01-01

    Full Text Available With the development of the high performance and high reliability of aeroengine, the blade-tip radial running clearance (BTRRC of high pressure turbine seriously influences the reliability and performance of aeroengine, wherein the radial deformation control of turbine casing has to be concerned in BTRRC design. To improve BTRRC design, the optimum control-based probabilistic optimization of turbine casing radial deformation was implemented using time-varying least square support vector machine (T-LSSVM by considering nonlinear material properties and dynamic thermal load. First the T-LSSVM method was proposed and its mathematical model was established. And then the nonlinear dynamic optimal control model of casing radial deformation was constructed with T-LSSVM. Thirdly, through the numerical experiments, the T-LSSVM method is demonstrated to be a promising approach in reducing additional design samples and improving computational efficiency with acceptable computational precision. Through the optimum control-based probabilistic optimization for nonlinear dynamic radial turbine casing deformation, the optimum radial deformation is 7.865 × 10−4 m with acceptable reliability degree 0.995 6, which is reduced by 7.86 × 10−5 m relative to that before optimization. These results validate the effectiveness and feasibility of the proposed T-LSSVM method, which provides a useful insight into casing radial deformation, BTRRC control, and the development of gas turbine with high performance and high reliability.

  8. Moving Particle Semi-implicit method: a numerical method for thermal hydraulic analysis with topological deformations

    International Nuclear Information System (INIS)

    Koshizuka, S.; Oka, Y.

    1997-01-01

    Moving Particle Semi-implicit (MPS) method is presented. Partial differential operators in the governing equations, such as gradient and Laplacian, are modeled as particle interactions without grids. A semi-implicit algorithm is used for incompressible flow analysis. In the present study, calculation models of moving solids, thin structures and phase change between liquid and gas are developed. Interaction between breaking waves and a floating solid is simulated using the model of moving solids. Calculations of collapsing water with a vertical thin plate show that water spills out over the plate which is largely deformed. Impingement of water jets on a molten metal pool is analyzed to investigate fundamental processes of vapor explosions. Water, vapor and molten metal are simultaneously calculated with evaporation. This calculation reveals that filaments of the molten metal emerge as the fragmentation process of vapor explosions. The MPS method is useful for complex problems involving moving interfaces even if topological deformations occur. (author)

  9. Time-Dependent Thermally-Driven Interfacial Flows in Multilayered Fluid Structures

    Science.gov (United States)

    Haj-Hariri, Hossein; Borhan, A.

    1996-01-01

    A computational study of thermally-driven convection in multilayered fluid structures will be performed to examine the effect of interactions among deformable fluid-fluid interfaces on the structure of time-dependent flow in these systems. Multilayered fluid structures in two models configurations will be considered: the differentially heated rectangular cavity with a free surface, and the encapsulated cylindrical liquid bridge. An extension of a numerical method developed as part of our recent NASA Fluid Physics grant will be used to account for finite deformations of fluid-fluid interfaces.

  10. In vitro deposition of hydroxyapatite on cortical bone collagen stimulated by deformation-induced piezoelectricity.

    Science.gov (United States)

    Noris-Suárez, Karem; Lira-Olivares, Joaquin; Ferreira, Ana Marina; Feijoo, José Luis; Suárez, Nery; Hernández, Maria C; Barrios, Esteban

    2007-03-01

    In the present work, we have studied the effect of the piezoelectricity of elastically deformed cortical bone collagen on surface using a biomimetic approach. The mineralization process induced as a consequence of the piezoelectricity effect was evaluated using scanning electron microscopy (SEM), thermally stimulated depolarization current (TSDC), and differential scanning calorimetry (DSC). SEM micrographs showed that mineralization occurred predominantly over the compressed side of bone collagen, due to the effect of piezoelectricity, when the sample was immersed in the simulated body fluid (SBF) in a cell-free system. The TSDC method was used to examine the complex collagen dielectric response. The dielectric spectra of deformed and undeformed collagen samples with different hydration levels were compared and correlated with the mineralization process followed by SEM. The dielectric measurements showed that the mineralization induced significant changes in the dielectric spectra of the deformed sample. DSC and TSDC results demonstrated a reduction of the collagen glass transition as the mineralization process advanced. The combined use of SEM, TSDC, and DSC showed that, even without osteoblasts present, the piezoelectric dipoles produced by deformed collagen can produce the precipitation of hydroxyapatite by electrochemical means, without a catalytic converter as occurs in classical biomimetic deposition.

  11. Real-Time Monitoring of Occupants’ Thermal Comfort through Infrared Imaging: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Boris Pavlin

    2017-02-01

    Full Text Available Thermally comfortable indoor environments are of great importance, as modern lifestyles often require people to spend more than 20 h per day indoors. Since most of the thermal comfort models use a variety of different environmental and personal factors that need to be measured or estimated, real-time and continuous assessment of thermal comfort is often not practically feasible. This work presents a cheap and non-invasive approach based on infrared imaging for monitoring the occupants’ thermal sensation and comfort in real time. Thanks to a mechatronic device developed by the authors, the imaging is performed on the forehead skin, selected because it is always exposed to the environment and, thus, facilitating the monitoring activity in a non-invasive manner. Tests have been performed in controlled conditions on ten subjects to assess the hypothesis that the forehead temperature is correlated with subjects’ thermal sensation. This allows the exploitation of this quantity as a base for a simple monitoring of thermal comfort, which could later be tuned with an extensive experimental campaign.

  12. solar thermal power systems advanced solar thermal technology project, advanced subsystems development

    Science.gov (United States)

    1979-01-01

    The preliminary design for a prototype small (20 kWe) solar thermal electric generating unit was completed, consisting of several subsystems. The concentrator and the receiver collect solar energy and a thermal buffer storage with a transport system is used to provide a partially smoothed heat input to the Stirling engine. A fossil-fuel combustor is included in the receiver designs to permit operation with partial or no solar insolation (hybrid). The engine converts the heat input into mechanical action that powers a generator. To obtain electric power on a large scale, multiple solar modules will be required to operate in parallel. The small solar electric power plant used as a baseline design will provide electricity at remote sites and small communities.

  13. q-Deformed KP Hierarchy and q-Deformed Constrained KP Hierarchy

    OpenAIRE

    He, Jingsong; Li, Yinghua; Cheng, Yi

    2006-01-01

    Using the determinant representation of gauge transformation operator, we have shown that the general form of $au$ function of the $q$-KP hierarchy is a $q$-deformed generalized Wronskian, which includes the $q$-deformed Wronskian as a special case. On the basis of these, we study the $q$-deformed constrained KP ($q$-cKP) hierarchy, i.e. $l$-constraints of $q$-KP hierarchy. Similar to the ordinary constrained KP (cKP) hierarchy, a large class of solutions of $q$-cKP hierarchy can be represent...

  14. Variability in Rock Thermal Properties in the Late Archean Crust of the Kapuskasing Structural Zone and Implications for its Thermal Structure and Metamorphic History.

    Science.gov (United States)

    Merriman, J. D.; Whittington, A. G.; Hofmeister, A. M.

    2017-12-01

    The thermal properties of rocks such as internal heat production and thermal diffusivity (α) play a key role in determining the thermal structure of the lithosphere, and consequently, the rates and styles of metamorphism within the crust. Over the last decade, measurements of α using the method laser flash analysis have shown the ability of a rock to conduct heat can vary by as much as a factor of 5 between common rock types, and decrease by up to a factor of 10 for the same rock between 25-1000°C. Here we present a preliminary model for the variability in rock throughout the crust based on measurements of the α of a suite of 100 samples from late Archean crust exposed in and around the Kapuskasing Structural Zone in Ontario, Canada. Preliminary results suggest that α is controlled primarily by mineralogy, and can vary not only between different rock types as described above, but also within the same rock by a factor of 1.5 (or more). Thermal diffusivity results were combined with heat producing element concentrations measured with ICP-MS to create a thermal model of the Kapuskasing Structural Zone prior its uplift and exposure. To provide additional constraints for P-T conditions within the pre-uplift KSZ crust, a combination of trace-element and pseudosection thermobarometry was used to estimate metamorphic temperatures during an extended period of crustal stability at the end of the Archean. Preliminary results were compared to finite-difference numerical models of the steady-state geothermal gradient using heat production back-calculated to 2.6 Ga. Results suggest a minimum thickness of the continental lithosphere during the late Archean of at least 150 km. To test the response of the crust to the effects of large thermal events such as pluton emplacement, we also performed time-dependent models of the thermal structure of the pre-uplift KSZ crust. These models suggest that heat from thermal events in the upper and middle crust result in a more insulating

  15. Effects of thermal underwear on thermal and subjective responses in winter.

    Science.gov (United States)

    Choi, Jeong-Wha; Lee, Joo-Young; Kim, So-Young

    2003-01-01

    This study was conducted to obtain basic data in improving the health of Koreans, saving energy and protecting environments. This study investigated the effects of wearing thermal underwear for keeping warm in the office in winter where temperature is not as low as affecting work efficiency, on thermoregulatory responses and subjective sensations. In order to create an environment where every subject feels the same thermal sensation, two experimental conditions were selected through preliminary experiments: wearing thermal underwear in 18 degrees C air (18-condition) and not wearing thermal underwear in 23 degrees C air (23-condition). Six healthy male students participated in this study as experiment subjects. Measurement items included rectal temperature (T(re)), skin temperature (T(sk)), clothing microclimate temperature (T(cm)), thermal sensation and thermal comfort. The results are as follows: (1) T(re) of all subjects was maintained constant at 37.1 degrees C under both conditions, indicating no significant differences. (2) (T)(sk) under the 18-condition and the 23-condition were 32.9 degrees C and 33.7 degrees C, respectively, indicating a significant level of difference (pcomfortable under both conditions. It was found (T)(sk) decreased due to a drop in the skin temperature of hands and feet, and the subjects felt cooler wearing only one layer of normal thermal underwear at 18 degrees C. Yet, the thermal comfort level, T(re) and T(cm) of chest part under the 18-condition were the same as those under the 23-condition. These results show that the same level of comfort, T(re) and T(cm) can be maintained as that of an environment about 5 degrees C higher in the office in winter, by wearing one layer of thermal underwear. In this regard, this study suggests that lowering indoor temperature by wearing thermal underwear in winter can contribute to saving energy and improving health.

  16. Thermal analysis of Yucca Mountain commercial high-level waste packages

    International Nuclear Information System (INIS)

    Altenhofen, M.K.; Eslinger, P.W.

    1992-10-01

    The thermal performance of commercial high-level waste packages was evaluated on a preliminary basis for the candidate Yucca Mountain repository site. The purpose of this study is to provide an estimate for waste package component temperatures as a function of isolation time in tuff. Several recommendations are made concerning the additional information and modeling needed to evaluate the thermal performance of the Yucca Mountain repository system

  17. Significant improvement in the thermal annealing process of optical resonators

    Science.gov (United States)

    Salzenstein, Patrice; Zarubin, Mikhail

    2017-05-01

    Thermal annealing performed during process improves the quality of the roughness of optical resonators reducing stresses at the periphery of their surface thus allowing higher Q-factors. After a preliminary realization, the design of the oven and the electronic method were significantly improved thanks to nichrome resistant alloy wires and chopped basalt fibers for thermal isolation during the annealing process. Q-factors can then be improved.

  18. Use of multiscale zirconium alloy deformation models in nuclear fuel behavior analysis

    Energy Technology Data Exchange (ETDEWEB)

    Montgomery, Robert, E-mail: robert.montgomery@pnnl.gov [Pacific Northwest National Laboratory (United States); Tomé, Carlos, E-mail: tome@lanl.gov [Los Alamos National Laboratory (United States); Liu, Wenfeng, E-mail: wenfeng.liu@anatech.com [ANATECH Corporation (United States); Alankar, Alankar, E-mail: alankar.alankar@iitb.ac.in [Indian Institute of Technology Bombay (India); Subramanian, Gopinath, E-mail: gopinath.subramanian@usm.edu [University of Southern Mississippi (United States); Stanek, Christopher, E-mail: stanek@lanl.gov [Los Alamos National Laboratory (United States)

    2017-01-01

    Accurate prediction of cladding mechanical behavior is a key aspect of modeling nuclear fuel behavior, especially for conditions of pellet-cladding interaction (PCI), reactivity-initiated accidents (RIA), and loss of coolant accidents (LOCA). Current approaches to fuel performance modeling rely on empirical constitutive models for cladding creep, growth and plastic deformation, which are limited to the materials and conditions for which the models were developed. To improve upon this approach, a microstructurally-based zirconium alloy mechanical deformation analysis capability is being developed within the United States Department of Energy Consortium for Advanced Simulation of Light Water Reactors (CASL). Specifically, the viscoplastic self-consistent (VPSC) polycrystal plasticity modeling approach, developed by Lebensohn and Tomé [1], has been coupled with the BISON engineering scale fuel performance code to represent the mechanistic material processes controlling the deformation behavior of light water reactor (LWR) cladding. A critical component of VPSC is the representation of the crystallographic nature (defect and dislocation movement) and orientation of the grains within the matrix material and the ability to account for the role of texture on deformation. A future goal is for VPSC to obtain information on reaction rate kinetics from atomistic calculations to inform the defect and dislocation behavior models described in VPSC. The multiscale modeling of cladding deformation mechanisms allowed by VPSC far exceed the functionality of typical semi-empirical constitutive models employed in nuclear fuel behavior codes to model irradiation growth and creep, thermal creep, or plasticity. This paper describes the implementation of an interface between VPSC and BISON and provides initial results utilizing the coupled functionality.

  19. Prediction on fracture risk of femur with Osteogenesis Imperfecta using finite element models: Preliminary study

    Science.gov (United States)

    Wanna, S. B. C.; Basaruddin, K. S.; Mat Som, M. H.; Mohamad Hashim, M. S.; Daud, R.; Majid, M. S. Abdul; Sulaiman, A. R.

    2017-10-01

    Osteogenesis imperfecta (OI) is a genetic disease which affecting the bone geometry. In a severe case, this disease can cause death to patients. The main issue of this disease is the prediction on bone fracture by the orthopaedic surgeons. The resistance of the bone to withstand the force before the bones fracture often become the main concern. Therefore, the objective of the present preliminary study was to investigate the fracture risk associated with OI bone, particularly in femur, when subjected to the self-weight. Finite element (FEA) was employed to reconstruct the OI bone model and analyse the mechanical stress response of femur before it fractures. Ten deformed models with different severity of OI bones were developed and the force that represents patient self-weight was applied to the reconstructed models in static analysis. Stress and fracture risk were observed and analysed throughout the simulation. None of the deformed model were observed experienced fracture. The fracture risk increased with increased severity of the deformed bone. The results showed that all deformed femur models were able to bear the force without experienced fracture when subjected to only the self-weight.

  20. Effects of Particle Size and Shape on U-Mo/Al Thermal Conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Tae-Won; Sohn, Dong-Seong [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-10-15

    The thermal conductivity of atomized U-Mo/Al dispersion fuels was measured only by Lee et al. by laser-flash and differential scanning calorimetry (DSC) methods. For the U-Mo particles, they are deformed during manufacturing process such as hot rolling and during irradiation by the creep deformation. Fricke developed a model for the effective thermal conductivity of a dilute suspension of randomly oriented spheroidal particles. In general, the thermal conductivity of composite increase when the particle shape is not sphere. This model is also based on continuum theory which assumes both temperature and heat flux are continuous across the interface. Kapitza, however, showed that there is a discontinuity in temperature across the interface at metal/liquid helium interface. In general, the discontinuity is from the thermal resistance at the interface. If the thermal resistance has a significant impact on the thermal conductivity, particle size is one of the essential parameter for determining the effective thermal conductivity of composite materials. Every, et al modified Bruggeman model to consider the interfacial thermal resistance. The U-Mo/Al dispersion fuel thermal conductivity calculation can be improved by considering the anisotropic effects and interface thermal resistances. There have been various works to analyze the thermal conductivity through Finite Element Method (FEM). Coulson developed a realistic FEM model to calculate the effective thermal conductivity of the fuel meat. This FEM model does not consider the anisotropic effects and interface thermal resistances. Therefore, these effects can be evaluated by comparing the FEM calculated effective thermal conductivity with measured data. In this work, the FEM analysis was done and the anisotropic effects and interface thermal resistances was estimated. From this results, the particle shape and size effects will be discussed. Many thermal conductivity models for the particle dispersed composites have been

  1. Effects of Particle Size and Shape on U-Mo/Al Thermal Conductivity

    International Nuclear Information System (INIS)

    Cho, Tae-Won; Sohn, Dong-Seong

    2014-01-01

    The thermal conductivity of atomized U-Mo/Al dispersion fuels was measured only by Lee et al. by laser-flash and differential scanning calorimetry (DSC) methods. For the U-Mo particles, they are deformed during manufacturing process such as hot rolling and during irradiation by the creep deformation. Fricke developed a model for the effective thermal conductivity of a dilute suspension of randomly oriented spheroidal particles. In general, the thermal conductivity of composite increase when the particle shape is not sphere. This model is also based on continuum theory which assumes both temperature and heat flux are continuous across the interface. Kapitza, however, showed that there is a discontinuity in temperature across the interface at metal/liquid helium interface. In general, the discontinuity is from the thermal resistance at the interface. If the thermal resistance has a significant impact on the thermal conductivity, particle size is one of the essential parameter for determining the effective thermal conductivity of composite materials. Every, et al modified Bruggeman model to consider the interfacial thermal resistance. The U-Mo/Al dispersion fuel thermal conductivity calculation can be improved by considering the anisotropic effects and interface thermal resistances. There have been various works to analyze the thermal conductivity through Finite Element Method (FEM). Coulson developed a realistic FEM model to calculate the effective thermal conductivity of the fuel meat. This FEM model does not consider the anisotropic effects and interface thermal resistances. Therefore, these effects can be evaluated by comparing the FEM calculated effective thermal conductivity with measured data. In this work, the FEM analysis was done and the anisotropic effects and interface thermal resistances was estimated. From this results, the particle shape and size effects will be discussed. Many thermal conductivity models for the particle dispersed composites have been

  2. Deformable microparticles with multiple functions for drug delivery and device testing

    Science.gov (United States)

    Thula, Taili T.

    Since the HIV epidemic of the 1990s, researchers have attempted to develop a red blood cell analog. Even though some of these substitutes are now in Phase III of clinical trials, their use is limited by side effects and short half-life in the human body. As a result, there is still a need for an effective erythrocyte analog with minimum immunogenic and side effects, so that it can be used for multiple applications. Finding new approaches to develop more efficient blood substitutes will not only bring valuable advances in the clinical approach, but also in the area of in vitro testing of medical devices. We examined the feasibility of creating a deformable multi-functional, biodegradable, biocompatible particle for applications in drug delivery and device testing. As a preliminary evaluation, we synthesized different types of microcapsules using natural and synthetic polymers, various cross-linking agents, and diverse manufacturing techniques. After fully characterizing of each system, we determined the most promising red blood cell analog in terms of deformability, stability and toxicity. We also examined the encapsulation and release of bovine serum albumin (BSA) within these deformable particles. After removal of cross-linkers, zinc- and copper-alginate microparticles surrounded by multiple polyelectrolyte layers of chitosan oligosaccharide and alginate were deformable and remained stable under physiological pressures applied by the micropipette technique. In addition, multiple coatings decreased toxicity of heavy-metal crosslinked particles. BSA encapsulation and release from chitosan-alginate microspheres were contingent on the crosslinker and number of polyelectrolyte coatings, respectively. Further rheological studies are needed to determine how closely these particles simulate the behavior of erythrocytes. Also, studies on the encapsulation and release of different proteins, including hemoglobin, are needed to establish the desired controlled release of

  3. A numerical model of mantle convection with deformable, mobile continental lithosphere within three-dimensional spherical geometry

    Science.gov (United States)

    Yoshida, M.

    2010-12-01

    stretched by the convecting mantle and may play a significant role in the stability of the cratonic lithosphere during the geological timescale because it acts as a buffer that prevents the cratonic lithosphere from undergoing global deformation. From geological evidence that a cratonic root survives at the surface for billions of years, the WCM may have existed in the past supercontinent throughout the Earth's geologic history. The preliminary model presented here should represent an important step toward realizing a more realistic model that could be used to address many outstanding geodynamic problems about the thermal and mechanical feedbacks between the mantle and continents and the temporal evolution of the Earth's mantle structure.

  4. A correct enthalpy relationship as thermal comfort index for livestock.

    Science.gov (United States)

    Rodrigues, Valéria Cristina; da Silva, Iran José Oliveira; Vieira, Frederico Márcio Corrêa; Nascimento, Sheila Tavares

    2011-05-01

    Researchers working with thermal comfort have been using enthalpy to measure thermal energy inside rural facilities, establishing indicator values for many situations of thermal comfort and heat stress. This variable turned out to be helpful in analyzing thermal exchange in livestock systems. The animals are exposed to an environment which is decisive for the thermoregulatory process, and, consequently, the reactions reflect states of thermal comfort or heat stress, the last being responsable for problems of sanity, behavior and productivity. There are researchers using enthalpy as a qualitative indicator of thermal environment of livestock such as poultry, cattle and hogs in tropical regions. This preliminary work intends to check different enthalpy equations using information from classical thermodynamics, and proposes a direct equation as thermal comfort index for livestock systems.

  5. Multiple-hook fixation in revision spinal deformity surgery for patients with a previous multilevel fusion mass: technical note and preliminary outcomes.

    Science.gov (United States)

    Liu, Ning; Wood, Kirkham B

    2017-03-01

    OBJECTIVE A previous multilevel fusion mass encountered during revision spinal deformity surgery may obscure anatomical landmarks, making instrumentation unworkable or incurring substantial blood loss and operative time. This study introduced a surgical technique of multiple-hook fixation for fixating previous multilevel fusion masses in revision spinal deformity surgeries and then evaluated its outcomes. METHODS Patients with a previous multilevel fusion mass who underwent revision corrective surgery down to the lumbosacral junction were retrospectively studied. Multiple hooks were used to fixate the fusion mass and linked to distal pedicle screws in the lumbosacral-pelvic complex. Radiological and clinical outcomes were evaluated. RESULTS The charts of 8 consecutive patients with spinal deformity were retrospectively reviewed (7 women, 1 man; mean age 56 years). The primary diagnoses included flat-back deformity (6 cases), thoracolumbar kyphoscoliosis (1 case), and lumbar spondylosis secondary to a previous scoliosis fusion (1 case). The mean follow-up duration was 30.1 months. Operations were performed at T3/4-ilium (4 cases), T7-ilium (1 case), T6-S1 (1 case), T12-S1 (1 case), and T9-L5 (1 case). Of 8 patients, 7 had sagittal imbalance preoperatively, and their mean C-7 plumb line improved from 10.8 ± 2.9 cm preoperatively to 5.3 ± 3.6 cm at final follow-up (p = 0.003). The mean lumbar lordosis of these patients at final follow-up was significantly greater than that preoperatively (35.2° ± 12.6° vs 16.8° ± 11.8°, respectively; p = 0.005). Two perioperative complications included osteotomy-related leg weakness in 1 patient and a stitch abscess in another. CONCLUSIONS The multiple-hook technique provides a viable alternative option for fixating a previous multilevel fusion mass in revision spinal deformity surgery.

  6. Deformations of superconformal theories

    Energy Technology Data Exchange (ETDEWEB)

    Córdova, Clay [School of Natural Sciences, Institute for Advanced Study,1 Einstein Drive, Princeton, NJ 08540 (United States); Dumitrescu, Thomas T. [Department of Physics, Harvard University,17 Oxford Street, Cambridge, MA 02138 (United States); Intriligator, Kenneth [Department of Physics, University of California,9500 Gilman Drive, San Diego, La Jolla, CA 92093 (United States)

    2016-11-22

    We classify possible supersymmetry-preserving relevant, marginal, and irrelevant deformations of unitary superconformal theories in d≥3 dimensions. Our method only relies on symmetries and unitarity. Hence, the results are model independent and do not require a Lagrangian description. Two unifying themes emerge: first, many theories admit deformations that reside in multiplets together with conserved currents. Such deformations can lead to modifications of the supersymmetry algebra by central and non-central charges. Second, many theories with a sufficient amount of supersymmetry do not admit relevant or marginal deformations, and some admit neither. The classification is complicated by the fact that short superconformal multiplets display a rich variety of sporadic phenomena, including supersymmetric deformations that reside in the middle of a multiplet. We illustrate our results with examples in diverse dimensions. In particular, we explain how the classification of irrelevant supersymmetric deformations can be used to derive known and new constraints on moduli-space effective actions.

  7. Behaviours of reinforced concrete containment models under thermal gradient and internal pressure

    International Nuclear Information System (INIS)

    Aoyagi, Y.; Ohnuma, H.; Yoshioka, Y.; Okada, K.; Ueda, M.

    1979-01-01

    The provisions for design concepts in Japanese Technical Standard of Concrete Containments for Nuclear Power Plants require to take account of thermal effects into design. The provisions also propose that the thermal effects could be relieved according to the degree of crack formation and creep of concrete, and may be neglected in estimating the ultimate strength capacity in extreme environmental loading conditions. This experimental study was carried out to clarify the above provisions by investigating the crack and deformation behaviours of two identical reinforced cylindrical models with dome and basement (wall outer diameter 160 cm, and wall thickness 10 cm). One of these models was hydraulically pressurized up to failure at room temperature and the other was subjected to similar internal pressure combined with the thermal gradient of approximately 40 to 50 0 C across the wall. Initial visual cracks were recognized when the stress induced by the thermal gradient reached at about 85% of bending strength of concrete used. The thermal stress of reinforcement calculated with the methods proposed by the authors using an average flexural rigidity considering the contribution of concrete showed good agreement with test results. The method based on the fully cracked section, however, was recognized to underestimate the measured stress. These cracks considerably reduced the initial deformation caused by subsequent internal pressure. (orig.)

  8. Preliminary Study of UAS Equipped with Thermal Camera for Volcanic Geothermal Monitoring in Taiwan.

    Science.gov (United States)

    Chio, Shih-Hong; Lin, Cheng-Horng

    2017-07-18

    Thermal infrared cameras sense the temperature information of sensed scenes. With the development of UASs (Unmanned Aircraft Systems), thermal infrared cameras can now be carried on a quadcopter UAV (Unmanned Aircraft Vehicle) to appropriately collect high-resolution thermal images for volcanic geothermal monitoring in a local area. Therefore, the quadcopter UAS used to acquire thermal images for volcanic geothermal monitoring has been developed in Taiwan as part of this study to overcome the difficult terrain with highly variable topography and extreme environmental conditions. An XM6 thermal infrared camera was employed in this thermal image collection system. The Trimble BD970 GNSS (Global Navigation Satellite System) OEM (Original Equipment Manufacturer) board was also carried on the quadcopter UAV to gather dual-frequency GNSS observations in order to determine the flying trajectory data by using the Post-Processed Kinematic (PPK) technique; this will be used to establish the position and orientation of collected thermal images with less ground control points (GCPs). The digital surface model (DSM) and thermal orthoimages were then produced from collected thermal images. Tests conducted in the Hsiaoyukeng area of Taiwan's Yangmingshan National Park show that the difference between produced DSM and airborne LIDAR (Light Detection and Ranging) data are about 37% between -1 m and 1 m, and 66% between -2 m and 2 m in the area surrounded by GCPs. As the accuracy of thermal orthoimages is about 1.78 m, it is deemed sufficient for volcanic geothermal monitoring. In addition, the thermal orthoimages show some phenomena not only more globally than do the traditional methods for volcanic geothermal monitoring, but they also show that the developed system can be further employed in Taiwan in the future.

  9. Preliminary Study of UAS Equipped with Thermal Camera for Volcanic Geothermal Monitoring in Taiwan

    Directory of Open Access Journals (Sweden)

    Shih-Hong Chio

    2017-07-01

    Full Text Available Thermal infrared cameras sense the temperature information of sensed scenes. With the development of UASs (Unmanned Aircraft Systems, thermal infrared cameras can now be carried on a quadcopter UAV (Unmanned Aircraft Vehicle to appropriately collect high-resolution thermal images for volcanic geothermal monitoring in a local area. Therefore, the quadcopter UAS used to acquire thermal images for volcanic geothermal monitoring has been developed in Taiwan as part of this study to overcome the difficult terrain with highly variable topography and extreme environmental conditions. An XM6 thermal infrared camera was employed in this thermal image collection system. The Trimble BD970 GNSS (Global Navigation Satellite System OEM (Original Equipment Manufacturer board was also carried on the quadcopter UAV to gather dual-frequency GNSS observations in order to determine the flying trajectory data by using the Post-Processed Kinematic (PPK technique; this will be used to establish the position and orientation of collected thermal images with less ground control points (GCPs. The digital surface model (DSM and thermal orthoimages were then produced from collected thermal images. Tests conducted in the Hsiaoyukeng area of Taiwan’s Yangmingshan National Park show that the difference between produced DSM and airborne LIDAR (Light Detection and Ranging data are about 37% between −1 m and 1 m, and 66% between −2 m and 2 m in the area surrounded by GCPs. As the accuracy of thermal orthoimages is about 1.78 m, it is deemed sufficient for volcanic geothermal monitoring. In addition, the thermal orthoimages show some phenomena not only more globally than do the traditional methods for volcanic geothermal monitoring, but they also show that the developed system can be further employed in Taiwan in the future.

  10. q-Deformed Kink solutions

    International Nuclear Information System (INIS)

    Lima, A.F. de

    2003-01-01

    The q-deformed kink of the λφ 4 -model is obtained via the normalisable ground state eigenfunction of a fluctuation operator associated with the q-deformed hyperbolic functions. The kink mass, the bosonic zero-mode and the q-deformed potential in 1+1 dimensions are found. (author)

  11. A survey of volcano deformation in the central Andes using InSAR: Evidence for deep, slow inflation

    Science.gov (United States)

    Pritchard, M. E.; Simons, M.

    2001-12-01

    We use interferometric synthetic aperture radar (InSAR) to survey about 50 volcanos of the central Andes (15-27o S) for deformation during the 1992-2000 time interval. Because of the remote location of these volcanos, the activity of most are poorly constrained. Using the ERS-1/2 C-band radars (5.6 cm), we observe good interferometric correlation south of about 21o S, but poor correlation north of that latitude, especially in southern Peru. This variation is presumably related to regional climate variations. Our survey reveals broad (10's of km), roughly axisymmetric deformation at 2 volcanic centers with no previously documented deformation. At Uturuncu volcano, in southwestern Bolivia, the deformation rate can be constrained with radar data from several satellite tracks and is about 1 cm/year between 1992 and 2000. We find a second source of volcanic deformation located between Lastarria and Cordon del Azufre volcanos near the Chile/Argentina border. There is less radar data to constrain the deformation in this area, but the rate is also about 1 cm/yr between 1996 and 2000. While the spatial character of the deformation field appears to be affected by atmosphere at both locations, we do not think that the entire signal is atmospheric, because the signal is observed in several interferograms and nearby edifices do not show similar patterns. The deformation signal appears to be time-variable, although it is difficult to determine whether this is due to real variations in the deformation source or atmospheric effects. We model the deformation with both a uniform point-source source of inflation, and a tri-axial point-source ellipsoid, and compare both elastic half-space and layered-space models. We also explore the effects of local topography upon the deformation field using the method of Williams and Wadge (1998). We invert for source parameters using the global search Neighborhood Algorithm of Sambridge (1998). Preliminary results indicate that the sources at both

  12. FFTF vertical sodium storage tank preliminary thermal analysis

    International Nuclear Information System (INIS)

    Irwin, J.J.

    1995-01-01

    In the FFTF Shutdown Program, sodium from the primary and secondary heat transport loops, Interim Decay Storage (IDS), and Fuel Storage Facility (FSF) will be transferred to four large storage tanks for temporary storage. Three of the storage tanks will be cylindrical vertical tanks having a diameter of 28 feet, height of 22 feet and fabricated from carbon steel. The fourth tank is a horizontal cylindrical tank but is not the subject of this report. The storage tanks will be located near the FFTF in the 400 Area and rest on a steel-lined concrete slab in an enclosed building. The purpose of this work is to document the thermal analyses that were performed to ensure that the vertical FFTF sodium storage tank design is feasible from a thermal standpoint. The key criterion for this analysis is the time to heat up the storage tank containing frozen sodium at ambient temperature to 400 F. Normal operating conditions include an ambient temperature range of 32 F to 120 F. A key parameter in the evaluation of the sodium storage tank is the type of insulation. The baseline case assumed six inches of calcium silicate insulation. An alternate case assumed refractory fiber (Cerablanket) insulation also with a thickness of six inches. Both cases assumed a total electrical trace heat load of 60 kW, with 24 kW evenly distributed on the bottom head and 36 kW evenly distributed on the tank side wall

  13. Insights on fluid-rock interaction evolution during deformation from fracture network geochemistry at reservoir-scale

    Science.gov (United States)

    Beaudoin, Nicolas; Koehn, Daniel; Lacombe, Olivier; Bellahsen, Nicolas; Emmanuel, Laurent

    2015-04-01

    Fluid migration and fluid-rock interactions during deformation is a challenging problematic to picture. Numerous interplays, as between porosity-permeability creation and clogging, or evolution of the mechanical properties of rock, are key features when it comes to monitor reservoir evolution, or to better understand seismic cycle n the shallow crust. These phenomenoms are especially important in foreland basins, where various fluids can invade strata and efficiently react with limestones, altering their physical properties. Stable isotopes (O, C, Sr) measurements and fluid inclusion microthermometry of faults cement and veins cement lead to efficient reconstruction of the origin, temperature and migration pathways for fluids (i.e. fluid system) that precipitated during joints opening or faults activation. Such a toolbox can be used on a diffuse fracture network that testifies the local and/or regional deformation history experienced by the rock at reservoir-scale. This contribution underlines the advantages and limits of geochemical studies of diffuse fracture network at reservoir-scale by presenting results of fluid system reconstruction during deformation in folded structures from various thrust-belts, tectonic context and deformation history. We compare reconstructions of fluid-rock interaction evolution during post-deposition, post-burial growth of basement-involved folds in the Sevier-Laramide American Rocky Mountains foreland, a reconstruction of fluid-rock interaction evolution during syn-depostion shallow detachment folding in the Southern Pyrenean foreland, and a preliminary reconstruction of fluid-rock interactions in a post-deposition, post-burial development of a detachment fold in the Appenines. Beyond regional specification for the nature of fluids, a common behavior appears during deformation as in every fold, curvature-related joints (related either to folding or to foreland flexure) connected vertically the pre-existing stratified fluid system

  14. Review of current capabilities for the measurement of stress, displacement, and in situ deformation modulus

    International Nuclear Information System (INIS)

    Schrauf, T.W.; Pratt, H.R.

    1979-12-01

    Current capabilities for the measurement of stress, displacement, and in situ deformation modulus in rock masses are reviewed as to their accuracy, sensitivity, advantages, and limitations. Consideration is given to both the instruments themselves and the measurement technique. Recommendations concerning adaptation of existing measurement techniques to repository monitoring are also discussed. These recommendations include: (1) development of a modified borehole deformation gage with improved long-term stability and reliability and reduced thermal sensitivity; (2) development of a downhole transducer type of extensometer; (3) development of a rigid inclusion type gage; (4) development of an improved vibrating wire stressmeter with greater accuracy and simplified calibration and installation requirements; and (5) modification of standard rod extensometers to improve their sensitivity

  15. Inelastic Cyclic Deformation Behaviors of Type 316H Stainless Steel for Reactor Pressure Vessel of Sodium-Cooled Fast Reactor at Elevated Temperatures

    International Nuclear Information System (INIS)

    Yoon, Ji-Hyun; Hong, Seokmin; Koo, Gyeong-Hoi; Lee, Bong-Sang; Kim, Young-Chun

    2015-01-01

    Type 316H stainless steel is a primary candidate material for a reactor pressure vessel of a sodium-cooled fast (SFR) reactor which is under development in Korea. The reactor pressure vessel for a SFR is subjected to inelastic deformation induced by cyclic thermal stress. Fully reversed cyclic testing and ratcheting testing at elevated temperatures were performed to characterize the inelastic cyclic deformation behaviors of Type 316H stainless steel at the SFR operating temperature. It was found that cyclic hardening of Type 316H stainless steel was enhanced, and the accumulation of ratcheting deformation of Type 316H stainless steel was retarded at around the SFR operating temperature. The results of the tensile testing and the microstructural investigation for dislocated structures after the inelastic deformation testing showed that dynamic strain aging affected the inelastic cyclic deformation behavior of Type 316 stainless steel at around the SFR operating temperature.

  16. Computer aided testing of steel samples deformation at coexistence liquid and solid phase

    International Nuclear Information System (INIS)

    Hojny, M.; Glowacki, M.

    2007-01-01

    The paper reports the results of experimental and theoretical work leading to construction of a CAE system dedicated to the numerical simulation of plastic deformation of steel at coexistence liquid and solid phase. A coupled thermal-mechanical model including inverse analysis technique was adopted for the solver. The advantage of the solution was the analytical form of both incompressibility and mass conservation conditions. This can prevent usual FEM variational solution problems concerning unintentional specimen volume loss caused by the numerical errors. The only well known machine allowing tests in the discussed temperature range is the GLEEBLE thermo-mechanical simulator. Experiments of deformation of steel in semi-solid state by using this machine are very expensive. Therefore, application of dedicated computer simulation system with inverse method makes tests possible and results in lowering testing cost

  17. Experimental deformation of a mafic rock - interplay between fracturing, reaction and viscous deformation

    Science.gov (United States)

    Marti, Sina; Stünitz, Holger; Heilbronner, Renée; Plümper, Oliver; Drury, Martyn

    2016-04-01

    Deformation experiments were performed on natural Maryland Diabase (˜ 55% Plg, 42% Px, 3% accessories, 0.18 wt.-% H2O added) in a Griggs-type deformation apparatus in order to explore the brittle-viscous transition and the interplay between deformation and mineral reactions. Shear experiments at strain rates of ˜ 2e-5 /s are performed, at T=600, 700 and 800°C and confining pressures Pc=1.0 and 1.5 GPa. Deformation localizes in all experiments. Below 700°C, the microstructure is dominated by brittle deformation with a foliation formed by cataclastic flow and high strain accommodated along 3-5 major ultracataclasite shear bands. At 700°C, the bulk of the material still exhibits abundant microfractures, however, deformation localizes into an anastomosing network of shear bands (SB) formed from a fine-grained (<< 1 μm) mixture of newly formed Plg and Amph. These reaction products occur almost exclusively along syn-kinematic structures such as fractures and SB. Experiments at 800°C show extensive mineral reactions, with the main reaction products Amph+Plg (+Zo). Deformation is localized in broad C' and C SB formed by a fine-grained (0.1 - 0.8 μm) mixture of Plg+Amph (+Zo). The onset of mineral reactions in the 700°C experiments shows that reaction kinetics and diffusional mass transport are fast enough to keep up with the short experimental timescales. While in the 700°C experiments brittle processes kinematically contribute to deformation, fracturing is largely absent at 800°C. Diffusive mass transfer dominates. The very small grain size within SB favours a grain size sensitive deformation mechanism. Due to the presence of water (and relatively high supported stresses), dissolution-precipitation creep is interpreted to be the dominant strain accommodating mechanism. From the change of Amph coronas around Px clasts with strain, we can determine that Amph is re-dissolved at high stress sites while growing in low stress sites, showing the ability of Amph to

  18. Temperature dependence of thermal pressure for NaCl

    Science.gov (United States)

    Singh, Chandra K.; Pande, Brijesh K.; Pandey, Anjani K.

    2018-05-01

    Engineering applications of the materials can be explored upto the desired limit of accuracy with the better knowledge of its mechanical and thermal properties such as ductility, brittleness and Thermal Pressure. For the resistance to fracture (K) and plastic deformation (G) the ratio K/G is treated as an indication of ductile or brittle character of solids. In the present work we have tested the condition of ductility and brittleness with the calculated values of K/G for the NaCl. It is concluded that the nature of NaCl can be predicted upto high temperature simply with the knowledge of its elastic stiffness constant only. Thermoelastic properties of materials at high temperature is directly related to thermal pressure and volume expansion of the materials. An expression for the temperature dependence of thermal pressure is formulated using basic thermodynamic identities. It is observed that thermal pressure ΔPth calculated for NaCl by using Kushwah formulation is in good agreement with the experimental values also the thermal pressure increases with the increase in temperature.

  19. Deformation of second and third quantization

    Science.gov (United States)

    Faizal, Mir

    2015-03-01

    In this paper, we will deform the second and third quantized theories by deforming the canonical commutation relations in such a way that they become consistent with the generalized uncertainty principle. Thus, we will first deform the second quantized commutator and obtain a deformed version of the Wheeler-DeWitt equation. Then we will further deform the third quantized theory by deforming the third quantized canonical commutation relation. This way we will obtain a deformed version of the third quantized theory for the multiverse.

  20. Deformations of the Almheiri-Polchinski model

    Energy Technology Data Exchange (ETDEWEB)

    Kyono, Hideki; Okumura, Suguru; Yoshida, Kentaroh [Department of Physics, Kyoto University, Kitashirakawa Oiwake-cho, Kyoto 606-8502 (Japan)

    2017-03-31

    We study deformations of the Almheiri-Polchinski (AP) model by employing the Yang-Baxter deformation technique. The general deformed AdS{sub 2} metric becomes a solution of a deformed AP model. In particular, the dilaton potential is deformed from a simple quadratic form to a hyperbolic function-type potential similarly to integrable deformations. A specific solution is a deformed black hole solution. Because the deformation makes the spacetime structure around the boundary change drastically and a new naked singularity appears, the holographic interpretation is far from trivial. The Hawking temperature is the same as the undeformed case but the Bekenstein-Hawking entropy is modified due to the deformation. This entropy can also be reproduced by evaluating the renormalized stress tensor with an appropriate counter-term on the regularized screen close to the singularity.

  1. Deformation and Phase Transformation Processes in Polycrystalline NiTi and NiTiHf High Temperature Shape Memory Alloys

    Science.gov (United States)

    Benafan, Othmane

    2012-01-01

    The deformation and transformation mechanisms of polycrystalline Ni49.9Ti50.1 and Ni50.3Ti29.7Hf20 (in at.%) shape memory alloys were investigated by combined experimental and modeling efforts aided by an in situ neutron diffraction technique at stress and temperature. The thermomechanical response of the low temperature martensite, the high temperature austenite phases, and changes between these two states during thermomechanical cycling were probed and reported. In the cubic austenite phase, stress-induced martensite, deformation twinning and slip processes were observed which helped in constructing a deformation map that contained the limits over which each of the identified mechanisms was dominant. Deformation of the monoclinic martensitic phase was also investigated where the microstructural changes (texture, lattice strains, and phase fractions) during room-temperature deformation and subsequent thermal cycling were compared to the bulk macroscopic response. When cycling between these two phases, the evolution of inelastic strains, along with the shape setting procedures were examined and used for the optimization of the transformation properties as a function of deformation levels and temperatures. Finally, this work was extended to the development of multiaxial capabilities at elevated temperatures for the in situ neutron diffraction measurements of shape memory alloys on the VULCAN Diffractometer at Oak Ridge National Laboratory.

  2. Thermal effects on beryllium mirrors

    International Nuclear Information System (INIS)

    Weinswig, S.

    1989-01-01

    Beryllium is probably the most frequently used material for spaceborne system scan mirrors. Beryllium's properties include lightweightedness, high Young's modulus, high stiffness value, high resonance value. As an optical surface, beryllium is usually nickel plated in order to produce a higher quality surface. This process leads to the beryllium mirror acting like a bimetallic device. The mirror's deformation due to the bimetallic property can possibly degrade the performance of the associated optical system. As large space borne systems are designed and as temperature considerations become more crucial in the instruments, the concern about temporal deformation of the scan mirrors becomes a prime consideration. Therefore, two sets of tests have been conducted in order to ascertain the thermal effects on nickel plated beryllium mirrors. These tests are categorized. The purpose of this paper is to present the values of the bimetallic effect on typical nickel plated beryllium mirrors

  3. Preliminary design analysis of hot gas ducts and a intermediate heat exchanger for the nuclear hydrogen reactor

    International Nuclear Information System (INIS)

    Song, K. N.; Kim, Y. W.

    2008-01-01

    Korea Atomic Energy Research Institute (KAERI) is in the process of carrying out a nuclear hydrogen system by considering the indirect cycle gas cooled reactors that produce heat at temperatures in the order of 950 .deg. C. Primary and secondary hot gas ducts with coaxial double tubes and are key components connecting a reactor pressure vessel and a intermediate heat exchanger for the nuclear hydrogen system. In this study, preliminary design analyses on the hot gas ducts and the intermediate heat exchanger were carried out. These preliminary design activities include a preliminary design on the geometric dimensions, a preliminary strength evaluation, thermal sizing, and an appropriate material selection

  4. Creep deformation behaviour and microstructural changes in Zr-2.5% Nb alloy

    International Nuclear Information System (INIS)

    Chaudhuri, S.; Singh, R.; Ghosh, R.N.; Sinha, T.K.; Banerjee, S.

    2002-01-01

    Cold worked and stress relieved Zr-2.5% Nb alloy is a well-known material used as pressure tubes in Pressurised Heavy Water Reactors. The pressure tubes, made of a typical Zr-alloy, consisting of 2.54% Nb, 0.1175% oxygen and less than 100 ppm impurities, are expected to withstand 9.5 MPa to 12.5 MPa pressure at 250 degC to 310 degC under fast neutron fluxes of 3.5 x 10 17 nm -2 s -1 . These tubes are made by hot extrusion at 780 degC with an extrusion ratio 8.3:1 and 40% cold pilgering followed by annealing at 550 degC for 3 hours and subsequently by 20-30% cold pilgering and stress relieving at 400 degC for 24 hours. The microstructure of such cold worked and stress relieved alloy consists of Β-Zr precipitates in the matrix of elongated Α-Zr grains. Although various factors such as irradiation creep, thermal creep, irradiation growth etc are responsible for limiting the life of pressure tubes; the thermal creep contributes significantly in overall creep deformation. Keeping this in view as well as due to non-availability of adequate published information including creep database on this alloy, an extensive investigation on the thermal creep behaviour of indigenously produced Zr-2.5% Nb alloy was undertaken. The creep tests in air using Mayes' creep testing machines were carried out in the temperature range of 300 degC to 450 degC under stresses in the range of 50 to 550 MPa. Analysis of data revealed that the mechanism of creep deformation remains the same in this range

  5. Dilatometry study of textures

    International Nuclear Information System (INIS)

    Sofrenovic, R.; Lazarevic, Dj.

    1965-01-01

    Presence of textures in the metal uranium fuel is harmful because of anisotropy properties of uranium during thermal treatment, and especially during irradiation. Anisotropic radiation swelling of uranium can cause deformation of fuel element due to existence of textures. The objective of this work was studying of the influence of phase transformations on textures in uranium which has undergone plastic deformation due to rotational casting. Dilatometry method was adopted for testing the textures. This report describes the device for dilatometry testing and the measured preliminary results are shown

  6. q-deformed Minkowski space

    International Nuclear Information System (INIS)

    Ogievetsky, O.; Pillin, M.; Schmidke, W.B.; Wess, J.; Zumino, B.

    1993-01-01

    In this lecture I discuss the algebraic structure of a q-deformed four-vector space. It serves as a good example of quantizing Minkowski space. To give a physical interpretation of such a quantized Minkowski space we construct the Hilbert space representation and find that the relevant time and space operators have a discrete spectrum. Thus the q-deformed Minkowski space has a lattice structure. Nevertheless this lattice structure is compatible with the operation of q-deformed Lorentz transformations. The generators of the q-deformed Lorentz group can be represented as linear operators in the same Hilbert space. (orig.)

  7. Thermal changes of the environment and their influence on reinforced concrete structures

    Science.gov (United States)

    Fojtik, R.; Cajka, R.

    2018-04-01

    The thermal expansion of concrete elements concerns both monolithic and prefabricated structures. Inappropriate design of dilation segments may cause minor but even larger failures. Critical environment factors are temperature-changing operations, such as unheated underground garages, where temperature fluctuations may occur depending on the exterior conditions. This paper numerically and experimentally analyses the thermal deformation of selected girders in the underground garages and the consequent structure failures, their causes, possible prevention and appropriate remediation.

  8. Variation of martensite lath width and precipitate size during creep deformation in a 10Cr-Mo steel

    International Nuclear Information System (INIS)

    Kim, S. H.; Song, B. Z.; Lu, W. S.

    2001-01-01

    The relationship between creep deformation and microstructural changes in martensitic 10Cr-MoW steel has been studied. Transmission electron microscopy and image analyser were used to determine the variation of precipitates and martensite lath width size during creep deformation and aging. As precipitates are coarsened during creep deformation, dislocations become easy to move and the recovery proceeds rapidly. This leads to the growth of lath width. The average size of precipitates was linearly increased with creep time. On the other hand the growth rate of lath width is constant until tertiary creep, but the growth of lath width is accelerated during tertiary creep. It has been concluded that the growth behavior of lath width are consistent with creep deformation. Because the growth of lath width is controlled by the coarsening of precipitates it is important to form more stable precipitates in creep condition for improvement of creep properties of martensitie steel. Microstructure of martensitic steel is thermally very stable, so the size of precipitates and martensite lath width are hardly changed during aging

  9. Rotary deformity in degenerative spondylolisthesis

    International Nuclear Information System (INIS)

    Kang, Sung Gwon; Kim, Jeong; Kho, Hyen Sim; Yun, Sung Su; Oh, Jae Hee; Byen, Ju Nam; Kim, Young Chul

    1994-01-01

    We studied to determine whether the degenerative spondylolisthesis has rotary deformity in addition to forward displacement. We have made analysis of difference of rotary deformity between the 31 study groups of symptomatic degenerative spondylolisthesis and 31 control groups without any symptom, statistically. We also reviewed CT findings in 15 study groups. The mean rotary deformity in study groups was 6.1 degree(the standard deviation is 5.20), and the mean rotary deformity in control groups was 2.52 degree(the standard deviation is 2.16)(p < 0.01). The rotary deformity can be accompanied with degenerative spondylolisthesis. We may consider the rotary deformity as a cause of symptomatic degenerative spondylolisthesis in case that any other cause is not detected

  10. Preliminary design study of the TMT Telescope structure system: overview

    Science.gov (United States)

    Usuda, Tomonori; Ezaki, Yutaka; Kawaguchi, Noboru; Nagae, Kazuhiro; Kato, Atsushi; Takaki, Junji; Hirano, Masaki; Hattori, Tomoya; Tabata, Masaki; Horiuchi, Yasushi; Saruta, Yusuke; Sofuku, Satoru; Itoh, Noboru; Oshima, Takeharu; Takanezawa, Takashi; Endo, Makoto; Inatani, Junji; Iye, Masanori; Sadjadpour, Amir; Sirota, Mark; Roberts, Scott; Stepp, Larry

    2014-07-01

    We present an overview of the preliminary design of the Telescope Structure System (STR) of Thirty Meter Telescope (TMT). NAOJ was given responsibility for the TMT STR in early 2012 and engaged Mitsubishi Electric Corporation (MELCO) to take over the preliminary design work. MELCO performed a comprehensive preliminary design study in 2012 and 2013 and the design successfully passed its Preliminary Design Review (PDR) in November 2013 and April 2014. Design optimizations were pursued to better meet the design requirements and improvements were made in the designs of many of the telescope subsystems as follows: 1. 6-legged Top End configuration to support secondary mirror (M2) in order to reduce deformation of the Top End and to keep the same 4% blockage of the full aperture as the previous STR design. 2. "Double Lower Tube" of the elevation (EL) structure to reduce the required stroke of the primary mirror (M1) actuators to compensate the primary mirror cell (M1 Cell) deformation caused during the EL angle change in accordance with the requirements. 3. M1 Segment Handling System (SHS) to be able to make removing and installing 10 Mirror Segment Assemblies per day safely and with ease over M1 area where access of personnel is extremely difficult. This requires semi-automatic sequence operation and a robotic Segment Lifting Fixture (SLF) designed based on the Compliance Control System, developed for controlling industrial robots, with a mechanism to enable precise control within the six degrees of freedom of position control. 4. CO2 snow cleaning system to clean M1 every few weeks that is similar to the mechanical system that has been used at Subaru Telescope. 5. Seismic isolation and restraint systems with respect to safety; the maximum acceleration allowed for M1, M2, tertiary mirror (M3), LGSF, and science instruments in 1,000 year return period earthquakes are defined in the requirements. The Seismic requirements apply to any EL angle, regardless of the

  11. Cyclic deformation of Nb single crystals

    International Nuclear Information System (INIS)

    Guiu, F.; Anglada, M.

    1982-01-01

    The temperature and strain-rate dependence of the cyclic flow stress of Nb single crystals with two different axial orientations has been studied at temperatures between 175 and 350 K. This dependence is found to be independent of the crystal orientation when the internal stresses are taken into account, and the results are discussed in terms of the theory of thermally activated dislocation glide. A transition temperature can be identified at about 250 K which separates two regions with different thermally activated deformation behaviour. Above this transition temperature the strain rate can be described by a stress power law, and the activation energy can be represented by a logarithmic function of the stress, as in Escaig's model of screw dislocation mobility. In the temperature range 170 to 250 K the results are also in agreement with the more recent model proposed by Seeger. The large experimental errors inherent in the values of activation enthalpy at low stresses are emphasized and taken into account in the discussion of the results. It is suggested that either impurity-kink interactions or the flexibility of the screw dislocations are responsible for the trend towards the high values of activation enthalpy measured at the low stresses. (author)

  12. Stability Evaluation of Buildings in Urban Area Using Persistent Scatterer Interfometry -Focused on Thermal Expansion Effect

    Science.gov (United States)

    Choi, J. H.; Kim, S. W.; Won, J. S.

    2017-12-01

    The objective of this study is monitoring and evaluating the stability of buildings in Seoul, Korea. This study includes both algorithm development and application to a case study. The development focuses on improving the PSI approach for discriminating various geophysical phase components and separating them from the target displacement phase. A thermal expansion is one of the key components that make it difficult for precise displacement measurement. The core idea is to optimize the thermal expansion factor using air temperature data and to model the corresponding phase by fitting the residual phase. We used TerraSAR-X SAR data acquired over two years from 2011 to 2013 in Seoul, Korea. The temperature fluctuation according to seasons is considerably high in Seoul, Korea. Other problem is the highly-developed skyscrapers in Seoul, which seriously contribute to DEM errors. To avoid a high computational burden and unstable solution of the nonlinear equation due to unknown parameters (a thermal expansion parameter as well as two conventional parameters: linear velocity and DEM errors), we separate a phase model into two main steps as follows. First, multi-baseline pairs with very short time interval in which deformation components and thermal expansion can be negligible were used to estimate DEM errors first. Second, single-baseline pairs were used to estimate two remaining parameters, linear deformation rate and thermal expansion. The thermal expansion of buildings closely correlate with the seasonal temperature fluctuation. Figure 1 shows deformation patterns of two selected buildings in Seoul. In the figures of left column (Figure 1), it is difficult to observe the true ground subsidence due to a large cyclic pattern caused by thermal dilation of the buildings. The thermal dilation often mis-leads the results into wrong conclusions. After the correction by the proposed method, true ground subsidence was able to be precisely measured as in the bottom right figure

  13. Failure Mechanisms of SAC/Fe-Ni Solder Joints During Thermal Cycling

    Science.gov (United States)

    Gao, Li-Yin; Liu, Zhi-Quan; Li, Cai-Fu

    2017-08-01

    Thermal cycling tests have been conducted on Sn-Ag-Cu/Fe- xNi ( x = 73 wt.% or 45 wt.%) and Sn-Ag-Cu/Cu solder joints according to the Joint Electron Device Engineering Council industrial standard to study their interfacial reliability under thermal stress. The interfacial intermetallic compounds formed for solder joints on Cu, Fe-73Ni, and Fe-45Ni were 4.5 μm, 1.7 μm, and 1.4 μm thick, respectively, after 3000 cycles, demonstrating excellent diffusion barrier effect of Fe-Ni under bump metallization (UBM). Also, two deformation modes, viz. solder extrusion and fatigue crack formation, were observed by scanning electron microscopy and three-dimensional x-ray microscopy. Solder extrusion dominated for solder joints on Cu, while fatigue cracks dominated for solder joints on Fe-45Ni and both modes were detected for those on Fe-73Ni. Solder joints on Fe-Ni presented inferior reliability during thermal cycling compared with those on Cu, with characteristic lifetime of 3441 h, 3190 h, and 1247 h for Cu, Fe-73Ni, and Fe-45Ni UBM, respectively. This degradation of the interfacial reliability for solder joints on Fe-Ni is attributed to the mismatch in coefficient of thermal expansion (CTE) at interconnection level. The CTE mismatch at microstructure level was also analyzed by electron backscatter diffraction for clearer identification of recrystallization-related deformation mechanisms.

  14. Thermal architecture of the SPICA/SAFARI instrument

    Science.gov (United States)

    Charles, Ivan; Duband, Lionel; Duval, Jean-Marc; Jackson, Brian; Jellema, Willem; Kooijman, Peter Paul; Luchier, Nicolas; Tirolien, Thierry; van Weers, Henk

    2012-09-01

    The SAFARI instrument is a far infrared imaging spectrometer that is a core instrument of the SPICA mission. Thanks to the large (3 meter) SPICA cold telescope, the ultra sensitive detectors and a powerful Fourier Transform Spectrometer, this instrument will give access to the faintest light never observed in the 34 μm - 210 μm bandwidth with a high spectral resolution. To achieve this goal, TES detectors, that need to be cooled at a temperature as low as 50 mK, have been chosen. The thermal architecture of the SAFARI focal plane unit (FPU) which fulfils the TES detector thermal requirements is presented. In particular, an original 50 mK cooler concept based on a sorption cooler in series with an adiabatic demagnetization refrigerator will be used. The thermal design of the detector focal plane array (FPA) that uses three temperature stages to limit the loads on the lowest temperature stage, will be also described. The current SAFARI thermal budget estimations are presented and discussed regarding the limited SPICA allocations. Finally, preliminary thermal sensitivity analysis dealing with thermal stability requirements is presented.

  15. Extremely deformable structures

    CERN Document Server

    2015-01-01

    Recently, a new research stimulus has derived from the observation that soft structures, such as biological systems, but also rubber and gel, may work in a post critical regime, where elastic elements are subject to extreme deformations, though still exhibiting excellent mechanical performances. This is the realm of ‘extreme mechanics’, to which this book is addressed. The possibility of exploiting highly deformable structures opens new and unexpected technological possibilities. In particular, the challenge is the design of deformable and bi-stable mechanisms which can reach superior mechanical performances and can have a strong impact on several high-tech applications, including stretchable electronics, nanotube serpentines, deployable structures for aerospace engineering, cable deployment in the ocean, but also sensors and flexible actuators and vibration absorbers. Readers are introduced to a variety of interrelated topics involving the mechanics of extremely deformable structures, with emphasis on ...

  16. Effect of thermal exposure on microstructure and nano-hardness of broached Inconel 718

    Directory of Open Access Journals (Sweden)

    Chen Zhe

    2014-01-01

    Full Text Available Inconel 718 is a high strength, heat resistant superalloy that is used extensively for components in hot sections of gas turbine engines. This paper presents an experimental study on the thermal stability of broached Inconel 718 in terms of microstructure and nano-hardness. The broaching process used in this study is similar to that used in gas turbine industries for machining fir-tree root fixings on turbine discs. Severe plastic deformation was found under the broached surface. The plastic deformation induces a work-hardened layer in the subsurface region with a thickness of ∼50 μm. Thermal exposure was conducted at two temperatures, 550 ∘C and 650 ∘C respectively, for 300 h. Recrystallization occurs in the surface layer during thermal exposure at 550 ∘C and α-Cr precipitates as a consequence of the growth of recrystallized δ phases. More recrystallized grains with a larger size form in the surface layer and the α-Cr not only precipitates in the surface layer, but also in the sub-surface region when the thermal exposure temperature goes up to 650 ∘C. The thermal exposure leads to an increase in nano-hardness both in the work-hardened layer and in the bulk material due to the coarsening of the main strengthening phase γ′′.

  17. Design of the deformable mirror demonstration CubeSat (DeMi)

    Science.gov (United States)

    Douglas, Ewan S.; Allan, Gregory; Barnes, Derek; Figura, Joseph S.; Haughwout, Christian A.; Gubner, Jennifer N.; Knoedler, Alex A.; LeClair, Sarah; Murphy, Thomas J.; Skouloudis, Nikolaos; Merck, John; Opperman, Roedolph A.; Cahoy, Kerri L.

    2017-09-01

    The Deformable Mirror Demonstration Mission (DeMi) was recently selected by DARPA to demonstrate in-space operation of a wavefront sensor and Microelectromechanical system (MEMS) deformable mirror (DM) payload on a 6U CubeSat. Space telescopes designed to make high-contrast observations using internal coronagraphs for direct characterization of exoplanets require the use of high-actuator density deformable mirrors. These DMs can correct image plane aberrations and speckles caused by imperfections, thermal distortions, and diffraction in the telescope and optics that would otherwise corrupt the wavefront and allow leaking starlight to contaminate coronagraphic images. DeMi is provide on-orbit demonstration and performance characterization of a MEMS deformable mirror and closed loop wavefront sensing. The DeMi payload has two operational modes, one mode that images an internal light source and another mode which uses an external aperture to images stars. Both the internal and external modes include image plane and pupil plane wavefront sensing. The objectives of the internal measurement of the 140-actuator MEMS DM actuator displacement are characterization of the mirror performance and demonstration of closed-loop correction of aberrations in the optical path. Using the external aperture to observe stars of magnitude 2 or brighter, assuming 3-axis stability with less than 0.1 degree of attitude knowledge and jitter below 10 arcsec RMSE, per observation, DeMi will also demonstrate closed loop wavefront control on an astrophysical target. We present an updated payload design, results from simulations and laboratory optical prototyping, as well as present our design for accommodating high-voltage multichannel drive electronics for the DM on a CubeSat.

  18. Deforming tachyon kinks and tachyon potentials

    International Nuclear Information System (INIS)

    Afonso, Victor I.; Bazeia, Dionisio; Brito, Francisco A.

    2006-01-01

    In this paper we investigate deformation of tachyon potentials and tachyon kink solutions. We consider the deformation of a DBI type action with gauge and tachyon fields living on D1-brane and D3-brane world-volume. We deform tachyon potentials to get other consistent tachyon potentials by using properly a deformation function depending on the gauge field components. Resolutions of singular tachyon kinks via deformation and applications of deformed tachyon potentials to scalar cosmology scenario are discussed

  19. Determining the thermal expansion coefficient of thin films for a CMOS MEMS process using test cantilevers

    International Nuclear Information System (INIS)

    Cheng, Chao-Lin; Fang, Weileun; Tsai, Ming-Han

    2015-01-01

    Many standard CMOS processes, provided by existing foundries, are available. These standard CMOS processes, with stacking of various metal and dielectric layers, have been extensively applied in integrated circuits as well as micro-electromechanical systems (MEMS). It is of importance to determine the material properties of the metal and dielectric films to predict the performance and reliability of micro devices. This study employs an existing approach to determine the coefficients of thermal expansion (CTEs) of metal and dielectric films for standard CMOS processes. Test cantilevers with different stacking of metal and dielectric layers for standard CMOS processes have been designed and implemented. The CTEs of standard CMOS films can be determined from measurements of the out-of-plane thermal deformations of the test cantilevers. To demonstrate the feasibility of the present approach, thin films prepared by the Taiwan Semiconductor Manufacture Company 0.35 μm 2P4M CMOS process are characterized. Eight test cantilevers with different stacking of CMOS layers and an auxiliary Si cantilever on a SOI wafer are fabricated. The equivalent elastic moduli and CTEs of the CMOS thin films including the metal and dielectric layers are determined, respectively, from the resonant frequency and static thermal deformation of the test cantilevers. Moreover, thermal deformations of cantilevers with stacked layers different to those of the test beams have been employed to verify the measured CTEs and elastic moduli. (paper)

  20. Thermal Behaviour of clay formations

    International Nuclear Information System (INIS)

    Tassoni, E.

    1985-01-01

    The programme carried out by ENEA to model the thermal-hydraulic-mechanical behaviour of the clay formations and to measure, in situ and in laboratory, the thermal properties of these rocks, is presented. An in situ heating experiment has been carried out in an open clay quarry in the area of Monterotondo, near Rome. The main goal of the experiment was to know the temperature field and the thermal effects caused by the high level radioactive waste disposed of in a clayey geological formation. The conclusions are as follows: - the thermal conduction codes are sufficiently accurate to forecast the temperature increases caused in the clay by the dissipation of the heat generated by high level radioactive waste; - the thermal conductivity deduced by means of the ''curve fitting'' method ranges from 0.015 to 0.017 W.cm -1 . 0 C -1 - the temperature variation associated with the transport of clay interstitial water caused by temperature gradient is negligible. A laboratory automated method has been designed to measure the thermal conductivity and diffusivity in clay samples. A review of experimental data concerning thermomechanical effects in rocks as well as results of thermal experiments performed at ISMES on clays are presented. Negative thermal dilation has been found both in the elastic and plastic range under constant stress. Thermoplastic deformation appears ten times greater than the thermoelastic one. A mathematical model is proposed in order to simulate the above and other effects that encompass thermal-elastic-plastic-pore water pressure response of clays at high temperature and effective pressure with undrained and transient drainage conditions. Implementation of the two versions into a finite element computer code is described