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Sample records for uniaxial tensile testing

  1. Failure analysis based on microvoid growth for sheet metal during uniaxial and biaxial tensile tests

    International Nuclear Information System (INIS)

    Abbassi, Fethi; Mistou, Sebastien; Zghal, Ali

    2013-01-01

    Highlights: ► Cruciform specimen designed and biaxial tensile test carried out. ► Stereo Correlation Image technique is used for 3D full-filed measurements. ► SEM fractography analysis is used to explain the fracture mechanism. ► Constitutive modeling of the necking phenomenon was developed using GTN model. - Abstract: The aim of the presented investigations is to perform an analysis of fracture and instability during simple and complex load testing by addressing the influence of ductile damage evolution in necking processes. In this context, an improved experimental methodology was developed and successfully used to evaluate localization of deformation during uniaxial and biaxial tensile tests. The biaxial tensile tests are carried out using cruciform specimen loaded using a biaxial testing machine. In this experimental investigation, Stereo-Image Correlation technique has is used to produce the heterogeneous deformations map within the specimen surface. Scanning electron microscope is used to evaluate the fracture mechanism and the micro-voids growth. A finite element model of uniaxial and biaxial tensile tests are developed, where a ductile damage model Gurson–Tvergaard–Needleman (GTN) is used to describe material deformation involving damage evolution. Comparison between the experimental and the simulation results show the accuracy of the finite element model to predict the instability phenomenon. The advanced measurement techniques contribute to understand better the ductile fracture mechanism

  2. Experimental and numerical study on mechanical properties of aluminum alloy under uniaxial tensile test

    Directory of Open Access Journals (Sweden)

    O. Daghfas

    2017-01-01

    Full Text Available The main objective is to model the behavior of 7075 aluminum alloy and built an experimental database to identify the model parameters. The first part of the paper presents an experimental database on 7075 aluminum alloy. Thus, uniaxial tensile tests are carried in three loading directions relative to the rolling direction, knowing that the fatigue of aircraft structures is traditionally managed based on the assumption of uniaxial loads. From experimental database, the mechanical properties are extracted, particularly the various fractures owing to pronounced anisotropy relating to material. In second part, plastic anisotropy is then modeled using the identification strategy which depends on yield criteria, hardening law and evolution law. In third part, a comparison with experimental data shows that behavior model can successfully describe the anisotropy of the Lankford coefficient.

  3. Tensile testing

    CERN Document Server

    2004-01-01

    A complete guide to the uniaxial tensile test, the cornerstone test for determining the mechanical properties of materials: Learn ways to predict material behavior through tensile testing. Learn how to test metals, alloys, composites, ceramics, and plastics to determine strength, ductility and elastic/plastic deformation. A must for laboratory managers, technicians, materials and design engineers, and students involved with uniaxial tensile testing. Tensile Testing , Second Edition begins with an introduction and overview of the test, with clear explanations of how materials properties are determined from test results. Subsequent sections illustrate how knowledge gained through tensile tests, such as tension properties to predict the behavior (including strength, ductility, elastic or plastic deformation, tensile and yield strengths) have resulted in improvements in materals applications. The Second Edition is completely revised and updated. It includes expanded coverage throughout the volume on a variety of ...

  4. On the identifiability of the Hill-1948 model with one uniaxial tensile test

    Science.gov (United States)

    Bertin, Morgan; Hild, François; Roux, Stéphane

    2017-06-01

    A uniaxial experiment is performed on an ultra-thin specimen made of 17-7 precipitation hardened stainless steel. An anti-wrinkling setup allows for the characterization of the mechanical behavior with Integrated Digital Image Correlation (IDIC). The result shows that a single uniaxial experiment investigated via IDIC possesses enough data (and even more) to characterize a complete anisotropic elastoplastic model.

  5. Analysis of surface roughening behavior of 6063 aluminum alloy by tensile testing of a trapezoidal uniaxial specimen

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yang [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150090 (China); Wang, Xiaosong, E-mail: hitxswang@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150090 (China); National Key Laboratory of Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001 (China); Yuan, Shijian [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150090 (China); National Key Laboratory of Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001 (China)

    2016-08-30

    To determine the quantitative relationship between surface roughness and strain, the surface roughening behavior of a 6063 aluminum alloy tube was examined by tensile testing of a trapezoidal uniaxial specimen, that can provide a continuous strain distribution after tensile deformation. The surface roughness was measured using a laser scanning confocal microscope to reflect the degree of roughening. The microstructure and surface morphology were examined using electron back-scattered diffraction and in-situ scanning electron microscopy to determine the grain orientation and surface topography evolution. The surface roughness increased with strain when the strain was less than 0.067 and then decreased slightly, with a maximum surface roughness of 23.73 µm. Inhomogeneous deformation at the grain boundaries and inside the grains was enhanced with increasing strain, resulting in an increase of surface roughness when the strain was below a critical value. As the strain increased, a greater number of slip systems contributed to the further deformation. Thus, the strain became more homogeneous, and accordingly, the surface roughness slightly decreased.

  6. Investigation of the Failure Mechanism of HTPB/AP/Al Propellant by In-situ Uniaxial Tensile Experimentation in SEM

    NARCIS (Netherlands)

    Ramshorst, M.C.J. van; Benedetto, G.L. di; Duvalois, W.; Hooijmeijer, P.A.; Heijden, A.E.D.M. van der

    2016-01-01

    The failure mechanism of a propellant consisting of hydroxyl terminated poly-butadiene filled with ammonium perchlorate and aluminum (HTPB/AP/Al) was determined by performing in-situ uniaxial tensile tests in a scanning electron microscope (SEM). The experimental test plan contained uniaxial tensile

  7. Mechanical properties of graphene nanoribbons under uniaxial tensile strain

    Science.gov (United States)

    Yoneyama, Kazufumi; Yamanaka, Ayaka; Okada, Susumu

    2018-03-01

    Based on the density functional theory with the generalized gradient approximation, we investigated the mechanical properties of graphene nanoribbons in terms of their edge shape under a uniaxial tensile strain. The nanoribbons with armchair and zigzag edges retain their structure under a large tensile strain, while the nanoribbons with chiral edges are fragile against the tensile strain compared with those with armchair and zigzag edges. The fracture started at the cove region, which corresponds to the border between the zigzag and armchair edges for the nanoribbons with chiral edges. For the nanoribbons with armchair edges, the fracture started at one of the cove regions at the edges. In contrast, the fracture started at the inner region of the nanoribbons with zigzag edges. The bond elongation under the tensile strain depends on the mutual arrangement of covalent bonds with respect to the strain direction.

  8. Uniaxial Tension Test of Slender Reinforced Early Age Concrete Members

    Directory of Open Access Journals (Sweden)

    Wenbo Zhang

    2011-08-01

    Full Text Available The present study aims to obtain the tensile properties of early age concrete based on a uniaxial tension test employing RC slender members. First, the paper shows that concrete strain is equal to the strain of rebar at the mid-span of the RC member. The tensile Young’s modulus and the strain capacity of early age concrete are estimated using strain measurements. The experiment indicated that the tensile Young’s modulus at an early age is higher than the compressive modulus. This observation was similar to one found in a previous investigation which used a direct tension test of early age concrete. Moreover, the paper describes how an empirical equation for mature concrete can be applied to the relation between uniaxial tensile strength and splitting tensile strength even in early age concrete. Based on a uniaxial tension test, the paper proposes an empirical equation for the relationship between standard bond stresses and relative slip.

  9. Influence of Simulated Acid Rain Corrosion on the Uniaxial Tensile Mechanical Properties of Concrete

    Directory of Open Access Journals (Sweden)

    Ying-zi Zhang

    2012-01-01

    Full Text Available An experimental study on the uniaxial tensile property of concrete exposed to the acid rain environment was carried out. Acid rain with pH level of 1.0 was deposed by the mixture of sulfate and nitric acid solution in the laboratory. Dumbbell-shaped concrete specimens were immersed in the simulated acid rain completely. After being exposed to the deposed mixture for a certain period, uniaxial tensile test was performed on the concrete specimens. The results indicate that elastic modulus, tensile strength, and peak strain have a slight increase at the initial corrosion stage, and with the extension of corrosion process, elastic modulus and tensile strength decrease gradually, while the peak strain still increases. It is found that the compressive strength is more sensitive than the tensile strength in aggressive environment. Based on the experimental results, an equation was proposed to describe the ascending branch of the stress-strain curve of the concrete corroded by acid rain.

  10. Mechanical Behavior of Red Sandstone under Incremental Uniaxial Cyclical Compressive and Tensile Loading

    Directory of Open Access Journals (Sweden)

    Baoyun Zhao

    2017-01-01

    Full Text Available Uniaxial experiments were carried out on red sandstone specimens to investigate their short-term and creep mechanical behavior under incremental cyclic compressive and tensile loading. First, based on the results of short-term uniaxial incremental cyclic compressive and tensile loading experiments, deformation characteristics and energy dissipation were analyzed. The results show that the stress-strain curve of red sandstone has an obvious memory effect in the compressive and tensile loading stages. The strains at peak stresses and residual strains increase with the cycle number. Energy dissipation, defined as the area of the hysteresis loop in the stress-strain curves, increases nearly in a power function with the cycle number. Creep test of the red sandstone was also conducted. Results show that the creep curve under each compressive or tensile stress level can be divided into decay and steady stages, which cannot be described by the conventional Burgers model. Therefore, an improved Burgers creep model of rock material is constructed through viscoplastic mechanics, which agrees very well with the experimental results and can describe the creep behavior of red sandstone better than the Burgers creep model.

  11. An effective uniaxial tensile stress-strain relationship for prestressed concrete

    International Nuclear Information System (INIS)

    Chitnuyanondh, L.; Rizkalla, S.; Murray, D.W.; MacGregor, J.G.

    1979-02-01

    This report evaluates the direct tensile strength and an equivalent uniaxial tensile stress-strain relationship for prestressed concrete using data from specimens tested at the University of Alberta which represent segments from the wall of a containment vessel. The stress-strain relationship, when used in conjunction with the BOSOR5 program, enables prediction of the response of prestressed concrete under any biaxial combination of compressive and/or tensile stresses. Comparisons between the experimental and analytical (BOSOR5) load-strain response of the wall segments are also presented. It is concluded that the BOSOR5 program is able to predict satisfactorily the response of the wall segments and multi-layered shell structures. (author)

  12. Uniaxial and Multiaxial Creep Testing of Copper

    International Nuclear Information System (INIS)

    Auerkari, Pertti; Holmstroem, Stefan; Veivo, Juha; Salonen, Jorma; Nenonen, Pertti; Laukkanen, Anssi

    2003-12-01

    Multiaxial (compact tension, CT) creep testing has been performed for copper with 79 ppm phosphorus and 60 ppm oxygen. The test load levels were selected according to results from preceding uniaxial creep testing and FE analysis of the CT specimens. Interrupted testing was used for metallographic inspection of the specimens for creep damage. After 7,900 h and 10,300 h of testing at 150 deg C and 46 MPa (reference stress), inspected CT specimens showed cavity indications with a low maximum density ( 2 ) and a typical maximum dimension of less than about 1 μm near the notch tip. From previous experience on creep cavitation damage, the expected minimum life to crack initiation at the notch tip would be at least 40,000 hours, but could be considerably longer because the cavity indications are suspected to originate at least partly from precipitates in specimen preparation. The interrupted testing of CT specimens also showed a 'segregation zone' along some grain boundaries, mainly near the notch tip. This zone appears to contain more P and O than the surrounding matrix, but less than the narrow grain boundary films that are already present in the as-new material. The zone is readily etched and shows a relatively sharp edge towards the matrix without an obvious phase boundary. Using converted multiaxial (CT) testing results, the predicted isothermal uniaxial creep life at 150 deg C/46 MPa is about 1,900 years. The corresponding creep life directly predicted from uniaxial data is 3,100 years, when estimated from a parametric best fit expression according to PD6605. Although the two results are satisfactorily within a factor of two in time, the uncertainties in the extended extrapolations remain large. Further testing is recommended, with at least two creep enhancing factors present. Such testing could include notched creep testing at 120-180 deg C in a corrosive environment, and notched model vessel creep testing at elevated pressure. It is also recommended that longer

  13. Uniaxial compression test series on Bullfrog Tuff

    International Nuclear Information System (INIS)

    Price, R.H.; Jones, A.K.; Nimick, K.G.

    1982-04-01

    Nineteen uniaxial compressive experiments were performed on samples of the Bullfrog Member of the Crater Flat Tuff, obtained from drillhole USW-G1 at Yucca Mountain on the Nevada Test Site. The water saturated samples were deformed at a nominal strain rate of 10 -5 sec -1 , atmospheric pressure and room temperature. Resultant unconfined compressive strengths, axial strains to failure, Young's moduli and Poisson's ratios ranged from 4.63 to 153. MPa, .0028 to .0058, 2.03 to 28.9 GPa and .08 to .16, respectively

  14. Aging enhances the vulnerability of mesenchymal stromal cells to uniaxial tensile strain-induced apoptosis.

    Science.gov (United States)

    McKayed, Katey; Prendergast, Patrick J; Campbell, Veronica A

    2016-02-08

    Mechanical priming can be employed in tissue engineering strategies to control the fate and differentiation pattern of mesenchymal stromal cells. This is relevant to regenerative medicine whereby mechanical cues can promote the regeneration of a specific tissue type from mesenchymal precursors. The ability of cells to respond to mechanical forces is dependent upon mechanotransduction pathways that involve membrane-associated proteins, such as integrins. During the aging process changes in the mechanotransduction machinery may influence how cells from aged individuals respond to mechanical priming. In this study mesenchymal stromal cells were prepared from young adult and aged rats and exposed to uniaxial tensile strain at 5% and 10% for 3 days, or 2.5% for 7 days. Application of 5% tensile strain had no impact on cell viability. In contrast, application of 10% tensile strain evoked apoptosis and the strain-induced apoptosis was significantly higher in the mesenchymal stromal cells prepared from the aged rats. In parallel to the age-related difference in cellular responsiveness to strain, an age-related decrease in expression of α2 integrin and actin, and enhanced lipid peroxidation was observed. This study demonstrates that mesenchymal stem cells from aged animals have an altered membrane environment, are more vulnerable to the pro-apoptotic effects of 10% tensile strain and less responsive to the pro-osteogenic effects of 2.5% tensile strain. Thus, it is essential to consider how aged cells respond to mechanical stimuli in order to identify optimal mechanical priming strategies that minimise cell loss, particularly if this approach is to be applied to an aged population. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Analysis of threshold current of uniaxially tensile stressed bulk Ge and Ge/SiGe quantum well lasers.

    Science.gov (United States)

    Jiang, Jialin; Sun, Junqiang; Gao, Jianfeng; Zhang, Ruiwen

    2017-10-30

    We propose and design uniaxially tensile stressed bulk Ge and Ge/SiGe quantum well lasers with the stress along direction. The micro-bridge structure is adapted for introducing uniaxial stress in Ge/SiGe quantum well. To enhance the fabrication tolerance, full-etched circular gratings with high reflectivity bandwidths of ~500 nm are deployed in laser cavities. We compare and analyze the density of state, the number of states between Γ- and L-points, the carrier injection efficiency, and the threshold current density for the uniaxially tensile stressed bulk Ge and Ge/SiGe quantum well lasers. Simulation results show that the threshold current density of the Ge/SiGe quantum well laser is much higher than that of the bulk Ge laser, even combined with high uniaxial tensile stress owing to the larger number of states between Γ- and L- points and extremely low carrier injection efficiency. Electrical transport simulation reveals that the reduced effective mass of the hole and the small conduction band offset cause the low carrier injection efficiency of the Ge/SiGe quantum well laser. Our theoretical results imply that unlike III-V material, uniaxially tensile stressed bulk Ge outperforms a Ge/SiGe quantum well with the same strain level and is a promising approach for Si-compatible light sources.

  16. In-situ observation of strain evolution in CP-Ti during uniaxial tensile loading

    Science.gov (United States)

    Bettles, C. J.; Gibson, M. A.; Stevenson, A. W.; Tomus, D.; Lynch, P. A.

    2010-07-01

    First results are presented for in-situ tensile loading experiments performed on the Powder Diffraction beamline at the Australian Synchrotron facility. For direct measurement of strain evolution, the beamline was fitted with a uniaxial tensile stage and a high-resolution CCD detector. Precise calibration of the experimental diffraction geometry, taking into account slight misalignment of the detector (pitch, roll, yaw), was achieved by simulation of the ring patterns recorded from the standard reference material LaB 6 (660). The material examined was a commercially pure titanium strip, which from prior electron microscopy studies, was found to have an average grain size of ˜20-30 μm. Tensile specimens conformed to ASTM E8, with a gauge length of 25 mm. To probe the bulk material properties all experiments were performed at 20 keV. In these preliminary experiments, measurement of the relative change in the interplanar lattice spacing was used to monitor the elastic response in seven crystallographic orientations during the loading cycle. To overcome problems encountered with grain size and associated discontinuous Debye-Scherrer ring patterns, two strategies were implemented to measure the Bragg peak (2 θB) positions. In cases where the radial integration routine provided inconsistent results for peak determination, a new approach based on determining the averaged sum of 2 θB positions from individual spots making up the ring pattern was utilised. Results obtained for the diffraction elastic modulus were found to be in agreement with predictions based on the single-crystal and Neerfield-Hill crystal coupling models.

  17. Prediction of hole expansion ratio for various steel sheets based on uniaxial tensile properties

    Science.gov (United States)

    Kim, Jae Hyung; Kwon, Young Jin; Lee, Taekyung; Lee, Kee-Ahn; Kim, Hyoung Seop; Lee, Chong Soo

    2018-01-01

    Stretch-flangeability is one of important formability parameters of thin steel sheets used in the automotive industry. There have been many attempts to predict hole expansion ratio (HER), a typical term to evaluate stretch-flangeability, using uniaxial tensile properties for convenience. This paper suggests a new approach that uses total elongation and average normal anisotropy to predict HER of thin steel sheets. The method provides a good linear relationship between HER of the machined hole and the predictive variables in a variety of materials with different microstructures obtained using different processing methods. The HER of the punched hole was also well predicted using the similar approach, which reflected only the portion of post uniform elongation. The physical meaning drawn by our approach successfully explained the poor HER of austenitic steels despite their considerable elongation. The proposed method to predict HER is simple and cost-effective, so it will be useful in industry. In addition, the model provides a physical explanation of HER, so it will be useful in academia.

  18. Examination and modeling of void growth kinetics in modern high strength dual phase steels during uniaxial tensile deformation

    Energy Technology Data Exchange (ETDEWEB)

    Saeidi, N., E-mail: navidsae@gmail.com [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Ashrafizadeh, F.; Niroumand, B. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Forouzan, M.R.; Mohseni mofidi, S. [Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Barlat, F. [Materials Mechanics Laboratory (MML), Graduate Institute of Ferrous Technology (GIFT), Pohang University of Science and Technology - POSTECH, San 31 Hyoja-dong, Nam-gu, Pohang, Gyeongbuk 790-784 (Korea, Republic of)

    2016-04-01

    Ductile fracture mechanisms during uniaxial tensile testing of two different modern high strength dual phase steels, i.e. DP780 and DP980, were studied. Detailed microstructural characterization of the strained and sectioned samples was performed by scanning electron microscopy as well as EBSD examination. The results revealed that interface decohesion, especially at martensite particles located at ferrite grain boundaries, was the most probable mechanism for void nucleation. It was also revealed that the creation of cellular substructure can reduce stored strain energy and thereby, higher true fracture strain was obtained in DP980 than DP780 steel. Prediction of void growth behavior based on some previously proposed models showed unreliable results. Therefore, a modified model based on Rice-Tracey family models was proposed which showed a very lower prediction error compared with other models. - Highlights: • Damage mechanism in two modern high strength dual phase steels was studied. • Creation of cellular substructures can reduce the stored strain energy within the ferrite grains. • The experimental values were examined by Agrawal as well as RT family models. • A modified model was proposed for prediction of void growth behavior of DP steels.

  19. Three-dimensional finite element modelling of the uniaxial tension test

    DEFF Research Database (Denmark)

    Østergaard, Lennart; Stang, Henrik

    2002-01-01

    . One of the most direct methods for determination of the σ-w relationship is the uniaxial tension test, where a notched specimen is pulled apart while the tensile load and the crack opening displacement is observed. This method is appealing since the interpretation is straightforward. The method......Experimental determination of the stress-crack opening relationship (σ-w) for concrete as defined in the fictitious crack model has proven to be difficult. This is due to the problems that may arise from application of the inverse analysis method necessary for the derivation of the relationship...... is examined in this paper through three dimensional finite element analyses. It is concluded that the interpretation of the uniaxial tension test is indeed straightforward, if the testing machine stiffness is sufficiently high....

  20. Experimental and numerical modeling of basalt textile reinforced mortar behavior under uniaxial tensile stress

    International Nuclear Information System (INIS)

    Larrinaga, Pello; Chastre, Carlos; Biscaia, Hugo C.; San-José, José T.

    2014-01-01

    Highlights: • Making more deepen the knowledge of textile reinforced mortar in tensile stress. • Analyzing the effect of the reinforcing ratio of the composite. • To compare results with Aveston–Cooper–Kelly theory. • To develop a numerical model based on a finite element code. • Considering the importance of the bond-slip law of the mortar-to-textile-interface. - Abstract: During the last years several projects and studies have improved the knowledge about textile reinforced mortar (TRM) technology. TRM has already been used in strengthening masonry and reinforced concrete structural elements such as walls, arches, columns and beams. This material is presented as a real alternative to the use of fiber-reinforced polymers (FRP) in situations where these composites have presented some drawbacks or their use is banned. Textile reinforced mortar show a complex mechanical behavior derived from the heterogeneity of the constituent materials. This paper aims to deepen the knowledge of this composite material in terms of tensile behavior. Following this scope, this paper presents an experimental campaign focused on thirty-one TRM specimens reinforced with four different reinforcing ratios. The results are analyzed and contrasted with two distinct models. (i) The Aveston–Cooper–Kelly theory (ACK) which is based on a tri-linear analytical approach; and (ii) a non-linear numerical simulation with a 3D finite element code. The finite element analysis (FEA) of the TRM tensile tests also showed no significant dependence on the basalt-to-mortar interface, i.e., the choice of a bond-slip curve in order to reproduce the bond stresses and slippages along the interface is irrelevant and it can be simply considered as rigid interface

  1. Processing, Structural Characterization and Comparative Studies on Uniaxial Tensile Properties of a New Type of Porous Twisted Wire Material

    Directory of Open Access Journals (Sweden)

    Fei Wu

    2015-08-01

    Full Text Available A self-developed rotary multi-cutter device cuts stainless steel wire ropes into segments to fabricate twisted wires. Stainless steel porous twisted wire materials (PTWMs with a spatial composite intertexture structure are produced by the compaction and subsequent vacuum solid-phase sintering of twisted wires. The stainless steel PTWMs show two types of typical uniaxial tensile failure modes, i.e., a 45° angle fracture mode and an auxetic failure mode (the PTWMs expand along the direction perpendicular to the tension. The effects of the sintering parameters, porosities, wire diameters, and sampling direction on the tensile properties of the PTWMs are carefully investigated. By increasing the sintering temperature from 1130 °C to 1330 °C, the tensile strength of the PTWMs with 70% target porosity increased from 7.7 MPa to 28.6 MPa and the total failure goes down to 50%. When increasing the sintering time from 90 min to 150 min, the tensile strength increases from 12.4 MPa to 19.1 MPa and the total failure elongation drops to 78.6%. The tensile strength of the PTWMs increases from 28.9 MPa to 112.7 MPa with decreasing porosity from 69.5% to 46.0%, and the total failure elongation also increases from 14.8% to 40.7%. The tensile strength and the failure strain of the PTWMs with fine wires are higher than those of the PTWMs with coarse wires under the same porosity. Sampling direction has a small influence on the tensile properties of the PTWMs.

  2. Final report on in-reactor uniaxial tensile deformation of pure iron and Fe-Cr alloy

    International Nuclear Information System (INIS)

    Singh, B.N.; Xiaoxu Huang; Taehtinen, S.; Moilamen, P.; Jacquet, P.; Dekeyser, J.

    2007-11-01

    Traditionally, the effect of irradiation on mechanical properties of metals and alloys is determined using post-irradiation tests carried out on pre-irradiated specimens and in the absence of irradiation environment. The results of these tests may not be representative of deformation behaviour of materials used in the structural components of a fission or fusion reactor where the materials will be exposed concurrently to displacement damage and external and/or internal stresses. In an effort to evaluate and understand the dynamic response of materials under these conditions, we have recently performed a series of uniaxial tensile tests on Fe-Cr and pure iron specimens in the BR-2 reactor at Mol (Belgium). The present report first provides a brief description of the test facilities and the procedure used for performing the in-reactor tests. The results on the mechanical response of materials during these tests are presented in the form of stress-displacement dose and the conventional stress-strain curves. For comparison, the results of post-irradiation tests and tests carried out on unirradiated specimens are also presented. Results of microstructural investigations on the unirradiated and deformed, irradiated and undeformed, post-irradiation deformed and the in-reactor deformed specimens are also described. During the in-reactor tests the specimens of both Fe-Cr alloy and pure iron deform in a homogeneous manner and do not exhibit the phenomenon of yield drop. An increase in the pre-yield dose increases the yield stress but not the level of maximum flow stress during the in-reactor deformation of Fe-Cr alloy. Neither the in-reactor nor the post-irradiation deformed specimens of Fe-Cr alloy and pure iron showed any evidence of cleared channel formation. Both in Fe-Cr and pure iron, the in-reactor deformation leads to accumulation of dislocations in a homogeneous fashion and only to a modest density. No dislocation cells are formed during the in-reactor or post

  3. Fabrication, Structural Characterization and Uniaxial Tensile Properties of Novel Sintered Multi-Layer Wire Mesh Porous Plates

    Directory of Open Access Journals (Sweden)

    Liuyang Duan

    2018-01-01

    Full Text Available There is an increasing interest in developing porous metals or metallic foams for functional and structural applications. The study of the physical and mechanical properties of porous metals is very important and helpful for their application. In this paper, a novel sintered multilayer wire mesh porous plate material (WMPPs with a thickness of 0.5 mm–3 mm and a porosity of 10–35% was prepared by winding, pressing, rolling, and subsequently vacuum sintering them. The pore size and total size distribution in the as-prepared samples were investigated using the bubble point method. The uniaxial tensile behavior of the WMPPs was investigated in terms of the sintering temperature, porosity, wire diameter, and manufacturing technology. The deformation process and the failure mechanism under the tensile press was also discussed based on the appearance of the fractures (SEM figures. The results indicated that the pore size and total size distribution were closely related to the raw material used and the sintering temperature. For the WMPPs prepared by the wire mesh, the pore structures were inerratic and the vast majority of pore size was less than 10 μm. On the other hand, for the WMPPs that were prepared by wire mesh and powder, the pore structures were irregular and the pore size ranged from 0 μm–50 μm. The experimental data showed that the tensile strength of WMPPs is much higher than any other porous metals or metallic foams. Higher sintering temperatures led to coarser joints between wires and resulted in higher tensile strength. The sintering temperature decreased from 1330 °C to 1130 °C and the tensile strength decreased from 296 MPa to 164 MPa. Lower porosity means that there are more metallurgical joints and metallic frameworks resisting deformation per unit volume. Therefore, lower porosities exhibit higher tensile strength. An increase of porosity from 17.14% to 32.5% led to the decrease of the tensile strength by 90 MPa. The

  4. Influence of sodium evnironment on the uniaxial tensile behavior of titanium modified type 316 stainless steel

    International Nuclear Information System (INIS)

    Natesan, K.; Chopra, O.K.; Kassner, T.F.

    1978-01-01

    True stress-true strain tensile data have been obtained for titanium modified type 316 stainless steel in the solution annealed condition and after exposure to a flowing sodium environment at temperature of 700, 650, 600 and 550 0 C. The specimens were exposed to sodium for times between 120 and 5012 h to produce carbon penetration depths in the range 0.05-0.30 mm. The Voce equation was used to describe tensile flow curves for plastic strains above 0.005. The results showed that, when compared with solution annealed specimens, the tensile flow behavior of the sodium exposed specimens is characterized by a higher strain hardening rate, which decreases rapidly as the flow stress increases. The loss in tensile ductility of the material due to carburization in sodium environment was found to be minimal. (Auth.)

  5. Dilatometer for use in tensile tests

    NARCIS (Netherlands)

    Coumans, W.J.; Heikens, D.

    1980-01-01

    An accurate dilatometer is described which permits simultaneous and automatic recording of sample vol. change during tensile tests on a com. tester. Liq. displacements in the dilatometer capillary, which correspond to vol. changes of the sample, are detected by a cond. meter. Tensile load is

  6. Measurement of tensile and fracture toughness properties using small punch test

    International Nuclear Information System (INIS)

    Chatterjee, S.; Shah Priti Kotak

    2005-05-01

    Small punch test wu carried out at room temperature on five different steels using 10 mm by 10 mm specimens of 0.4 mm thickness in a univesal testing machine. The tensile and fracture toughness properties of the five steels obtained from small punch test were compared with those obtained from the standard test method. The results (except in one steel) show that the tensile properties obtained from small punch test are in close proximity to those obtained ftom uni-axial tension test. The results also show that fracture toughness (Jic) properties obtained ftom small punch test are within ±20% of the corresponding values obtained using standard test procedures. (author)

  7. Uniaxial compression tests on diesel contaminated frozen silty soil specimens

    International Nuclear Information System (INIS)

    Chenaf, D.; Stampli, N.; Bathurst, R.; Chapuis, R.P.

    1999-01-01

    Results of a uniaxial, unconfined compression test on artificial diesel-contaminated and uncontaminated frozen silty soils are discussed. The testing program involved 59 specimens. The results show that for the same fluid content, diesel contamination reduced the strength of the frozen specimens by increasing the unfrozen water content. For example, in specimens containing 50 per cent diesel oil of the fluid content by weight the maximum strength was reduced by 95 per cent compared to the strength of an uncontaminated specimen. Diesel contamination was also shown to contribute to the slippage between soil particles by acting as a lubricant, thus accelerating the loss of compressive strength.13 refs., 18 figs

  8. Condition For Strain-Hardening In Ecc Uniaxial Test Specimen

    DEFF Research Database (Denmark)

    Dick-Nielsen, Lars; Stang, Henrik; Poulsen, Peter Noe

    2006-01-01

    and infinite sheets under uniaxial tension. The crack is assumed to be cohesive and the cohesive law applied takes into account fiber as well as mortar properties. It is shown that the maximum crack opening observed during crack propagation in various test specimen geometries is small, 20 m and also small......This paper discusses the adequateness of the steady state flat crack criterion for crack propagation in Engineered Cementitious Composites. The investigation is performed by use of a semi-analytical model as well as a Finite Element Model. The simulations are for one crack propagating in finite...

  9. In Situ Radiography During Tensile Tests

    Science.gov (United States)

    Baaklini, George Y.; Bhatt, Ramakrishna T.

    1994-01-01

    Laboratory system for testing specimens of metal-, ceramic-, and intermetallic-matrix composite materials incorporates both electromechanical tensile-testing subsystem and either of two imaging subsystems that take x-ray photographs of specimens before, during, and after tensile tests. Used to test specimens of reaction-bonded silicon nitride reinforced with silicon carbide fibers (SiC/RBSN) considered for high-temperature service in advanced aircraft turbine engines. Provides data on effects of preexisting flaws (e.g., high-density impurities and local variations of density) on fracture behavior. Accumulated internal damage monitored during loading. X-ray source illuminates specimen in load frame while specimen is pulled. X-ray images on film correlated with stress-vs.-strain data from tensile test.

  10. Performance enhancement in uniaxially tensile stressed GeSn n-channel fin tunneling field-effect transistor: Impact of stress direction

    Science.gov (United States)

    Wang, Hongjuan; Han, Genquan; Jiang, Xiangwei; Liu, Yan; Zhang, Chunfu; Zhang, Jincheng; Hao, Yue

    2017-04-01

    In this work, the boosting effect on the performance of GeSn n-channel fin tunneling FET (nFinTFET) enabled by uniaxial tensile stress is investigated theoretically. As the fin rotates within the (001) plane, the uniaxial tensile stress is always along its direction. The electrical characteristics of tensile-stressed GeSn nFinTFETs with point and line tunneling modes are computed utilizing the technology computer aided design (TCAD) simulator in which the dynamic nonlocal band-to-band tunneling (BTBT) algorithm is employed. In comparison with the relaxed devices, tensile-stressed GeSn nFinTFETs achieve a substantial enhancement in band-to-band tunneling generation rate (G BTBT) and on-state current I ON owing to the reduced bandgap E G induced by the tensile stress. Performance improvement of GeSn nFinTFETs induced by tensile stress demonstrates a strong dependence on channel direction and tunneling modes. Under the same magnitude of stress, line-nFinTFETs obtain a more pronounced I ON enhancement over the transistors with point tunneling mode.

  11. Induction Heating on Dynamic Tensile Tests in CEA Saclay

    International Nuclear Information System (INIS)

    Averty, X.; Yvon, P.; Duguay, C.; Pizzanelli, J. P.; Basini, V.

    2001-01-01

    The LCMI (Laboratory for characterization of irradiated materials), located in CEA from Saclay, is in charge of the mechanical tests on irradiated materials. The dynamic tensile testing machine, in a hot cell equipped with two remote handling, has been first improved in 1995, to fulfill the French safety programs on Reactivity Initiated Accident (RIA). One objective of this machine is to obtain mechanical property data on current Zircaloy cladding types needed to quality the cladding's response under RIA or LOCA transient loading and thermal conditions. For the RIA, this means testing at strain rates up to 5 s' and heating rates up to 200 degree centigree-s''-1, while for Loss of Coolant Accidents (LOCA) testing at strain rates of 10''-3 s''-1 and heating rates of 20 degree centigree s''-1 would be appropriate. The tensile samples are machined with a spark erosion machine, directly from pieces of cladding previously de fueled. Two kinds of samples can be machined in the cladding. Axial samples in order to test axial mechanical characteristics Ring samples in order to test transverse mechanical characteristics, more representative of RIA conditions. On one hand, the axial tensile tests were performed using the Joule effect, and heating rates up to about 500 degree centigree .s''-1 were obtained. This enabled us to perform the axial tests in a satisfactory manner. On the other hand, the tensile ring were first performed in a vertical furnace with a heating rate about 0.2 degree centigree.s''-1 and a thermal stability about 1 degree centigree. For temperatures above 480 degree centigree, the mechanical characteristics showed a sharp drop which could be attributed to irradiation defect annealing. Therefore we have recently developed an induction heating system to reach heating rates high enough (200 degree centigree.s''-1) to prevent any significant annealing before performing the ring tensile tests. To apply a uniaxial tangential tension, two matching half

  12. Microstructure evolution of titanium after tensile test

    International Nuclear Information System (INIS)

    Wronski, S.; Wierzbanowski, K.; Jędrychowski, M.; Tarasiuk, J; Wronski, M.; Baczmanski, A.; Bacroix, B.

    2016-01-01

    The qualitative and quantitative behavior of titanium T40 during tensile loading with a special emphasis on the presence of deformation twins in the observed microstructures is described. The samples for tensile tests were cut out from the rolled titanium sheet along the rolling and transverse directions. Several microstructure maps were determined using Electron Backscatter Diffraction technique (EBSD). These data were used to obtain crystallographic textures, misorientation distributions, grain size, twin boundary length, grain orientation spread, low and high angle boundary fractions and Schmid and Taylor factors. The deformation mechanisms and microstructure characteristics are different in the samples stretched along rolling and transverse directions. A strong appearance of tensile twins was observed in the samples deformed along transverse direction. On the other hand, more frequent subgrain formation and higher orientation spread was observed in the sample deformed along rolling direction, which caused’‘orientation blurring’ leading to an increase of grain size with deformation, as determined from OIM analysis.

  13. Uniaxial Tensile Properties of Atherosclerotic Carotid Artery After Mobilization of Pushing on Qiao-Gong: A Safety Study Using an Animal Model of Carotid Atherosclerosis.

    Science.gov (United States)

    Qi, Ji; Zhang, Shaoqun; Zhang, Lei; Ping, Ruiyue; Ping, Kaike; Ye, Da; Shen, Honggui; Chen, Yili; Li, Yikai

    2018-02-01

    This study aimed to preliminarily explore the effects of the soft tissue mobilization of pushing on Qiao-Gong (MPQ) on biomechanical properties of the carotid artery using an animal model of carotid atherosclerosis (CAS). Fifty rabbits were randomly divided into 4 groups: animals with CAS treated with MPQ (CAS-MPQ [n = 15]); animals with CAS treated without MPQ (CAS [n = 15]); normal animals treated with MPQ (normal-MPQ [n = 10]); and a blank control group (n = 10). The MPQ procedure consisted of soft tissue mobilization of the Qiao-Gong acupoint on the front edge of the sternocleidomastoid muscle applied from top to bottom, by flat pushing with the thumb repeatedly for 20 times. Disease in the CAS models was induced by carotid artery balloon injury combined with a high-fat diet for 12 weeks. At the end of modeling, carotid color Doppler ultrasonography examination was performed to confirm which animal models were successfully induced with CAS, excluding model rabbits without typical CAS at the same time. Then, MPQ was applied on rabbits in the CAS-MPQ and the normal-MPQ groups for 3 weeks. By contrast, rabbits in the other 2 groups were fed normally without MPQ. Uniaxial failure tests were later performed on carotid arteries in all 4 groups, and at the end of the study, a 2-way factorial analysis of variance of the results was conducted. (1) At the end of modeling, 10 rabbits in the CAS-MPQ group and 9 in the CAS group were included with typical carotid atherosclerotic characteristics. (2) Young's elastic modulus of the rabbit carotid artery increased more significantly in the CAS-MPQ group than the CAS group. (3) Compared with normal rabbit carotid arteries, atherosclerotic carotid arteries had lower levels of ultimate stress and ultimate strain but higher levels of ultimate load. The uniaxial tensile mechanical properties of the rabbit atherosclerotic carotid artery were impaired after MPQ. Copyright © 2018. Published by Elsevier Inc.

  14. Evaluation of ring tensile test results

    International Nuclear Information System (INIS)

    Chatterjee, S.; Anantharaman, S.; Balakrishnan, K.S.; Sivaramakrish, K.S.

    1990-01-01

    Ring specimens of 5-mm width cut from Zircaloy-2 cladding of reactor operated fuel elements that had experienced 5000 to 15,000 MWD/T of fuel burnup were subjected to ring tensile testing. The true stress-true strain data points up to the onset of necking from the individual load-elongation curves of these specimens were used as input data in Voce's equation. The results reveal that the uniform elongation (UE) values generated using Voce's equation were within (UE-2)% of the experimental percent uniform elongation (UE%). The corresponding ultimate tensile strength values were within ±1%. The uncertainty inherently associated in the determination of gauge length introduces extraneous deformation in the rings tested. Previous results had shown that a 14% increase in cladding diameter caused the gauge length to increase by 40%. To simulate the contribution of extraneous deformation due to an increase in cladding diameter, an analysis of the variation of the tensile parameters (uniform elongation and ultimate tensile strength) due to increase in the gauge length in the range of 10 to 40% was carried out. The results are discussed

  15. Deformation features of aluminium in tensile tests

    International Nuclear Information System (INIS)

    Quadros, N.F. de.

    1984-01-01

    It is presented a method to analyse stress-strain curves. Plastic and elastic strains were studied. The strains were done by tensile tests in four types of materials: highly pure aluminium, pure aluminium, commercially pure aluminium and aluminium - uranium. The chemical compositions were obtained by spectroscopy analysis and neutron activation analysis. Tensile tests were carried out at three strain rates, at room temperature, 100,200, 300 and 400 0 C, with knives extensometer and strain-gages to studied the elastic strain region. A multiple spring model based on two springs model to analyse elastic strain caused by tests without extensometers, taking in account moduli of elasticity and, an interactive analysis system with graphic capability were developed. It was suggested a qualitative model to explain the quantized multielasticity of Bell. (M.C.K.) [pt

  16. Uniaxial tension test on Rubber at constant true strain rate

    Directory of Open Access Journals (Sweden)

    Sourne H.L.

    2012-08-01

    Full Text Available Elastomers are widely used for damping parts in different industrial contexts because of their remarkable dissipation properties. Indeed, they can undergo severe mechanical loading conditions, i.e., high strain rates and large strains. Nevertheless, the mechanical response of these materials can vary from purely rubber-like to glassy depending on the strain rate undergone. Classically, uniaxial tension tests are made in order to find a relation between the stress and the strain in the material at various strain rates. However, even if the strain rate is searched to be constant, it is the nominal strain rate that is considered. Here we develop a test at constant true strain rate, i.e. the strain rate that is experienced by the material. In order to do such a test, the displacement imposed by the machine is an exponential function of time. This test has been performed with a high speed hydraulic machine for strain rates between 0.01/s and 100/s. A specific specimen has been designed, yielding a uniform strain field (and so a uniform stress field. Furthermore, an instrumented aluminum bar has been used to take into account dynamic effects in the measurement of the applied force. A high speed camera enables the determination of strain in the sample using point tracking technique. Using this method, the stress-strain curve of a rubber-like material during a loading-unloading cycle has been determined, up to a stretch ratio λ = 2.5. The influence of the true strain rate both on stiffness and on dissipation of the material is then discussed.

  17. Electrical characterization of Ω-gated uniaxial tensile strained Si nanowire-array metal-oxide-semiconductor field effect transistors with - and channel orientations

    International Nuclear Information System (INIS)

    Habicht, Stefan; Feste, Sebastian; Zhao, Qing-Tai; Buca, Dan; Mantl, Siegfried

    2012-01-01

    Nanowire-array metal-oxide-semiconductor field effect transistors (MOSFETs) were fabricated along and crystal directions on (001) un-/strained silicon-on-insulator substrates. Lateral strain relaxation through patterning was employed to transform biaxial tensile strain into uniaxial tensile strain along the nanowire. Devices feature ideal subthreshold swings and maximum on-current/off-current ratios of 10 11 for n and p-type transistors on both substrates. Electron and hole mobilities were extracted by split C–V method. For p-MOSFETs an increased mobility is observed for channel direction devices compared to devices. The n-MOSFETs showed a 45% increased electron mobility compared to devices. The comparison of strained and unstrained n-MOSFETs along and clearly demonstrates improved electron mobilities for strained channels of both channel orientations.

  18. Standard practice for verification of testing frame and specimen alignment under tensile and compressive axial force application

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 Included in this practice are methods covering the determination of the amount of bending that occurs during the application of tensile and compressive forces to notched and unnotched test specimens in the elastic range and to plastic strains less than 0.002. These methods are particularly applicable to the force application rates normally used for tension testing, creep testing, and uniaxial fatigue testing.

  19. Standard practice for verification of testing frame and specimen alignment under tensile and compressive axial force application

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2014-01-01

    1.1 Included in this practice are methods covering the determination of the amount of bending that occurs during the application of tensile and compressive forces to notched and unnotched test specimens in the elastic range and to plastic strains less than 0.002. These methods are particularly applicable to the force application rates normally used for tension testing, creep testing, and uniaxial fatigue testing.

  20. Relationship between local deformation behavior and crystallographic features of as-quenched lath martensite during uniaxial tensile deformation

    International Nuclear Information System (INIS)

    Michiuchi, M.; Nambu, S.; Ishimoto, Y.; Inoue, J.; Koseki, T.

    2009-01-01

    Electron backscattering diffraction patterns were used to investigate the relationship between local deformation behavior and the crystallographic features of as-quenched lath martensite of low-carbon steel during uniform elongation in tensile tests. The slip system operating during the deformation up to a strain of 20% was estimated by comparing the crystal rotation of each martensite block after deformation of 20% strain with predictions by the Taylor and Sachs models. The results indicate that the in-lath-plane slip system was preferentially activated compared to the out-of-lath-plane system up to this strain level. Further detailed analysis of crystal rotation at intervals of approximately 5% strain confirmed that the constraint on the operative slip system by the lath structure begins at a strain of 8% and that the local strain hardening of the primary slip systems occurred at approximately 15% strain.

  1. Effect of Uniaxial Tensile Cyclic Loading Regimes on Matrix Organization and Tenogenic Differentiation of Adipose-Derived Stem Cells Encapsulated within 3D Collagen Scaffolds

    Directory of Open Access Journals (Sweden)

    Gayathri Subramanian

    2017-01-01

    Full Text Available Adipose-derived mesenchymal stem cells have become a popular cell choice for tendon repair strategies due to their relative abundance, ease of isolation, and ability to differentiate into tenocytes. In this study, we investigated the solo effect of different uniaxial tensile strains and loading frequencies on the matrix directionality and tenogenic differentiation of adipose-derived stem cells encapsulated within three-dimensional collagen scaffolds. Samples loaded at 0%, 2%, 4%, and 6% strains and 0.1 Hz and 1 Hz frequencies for 2 hours/day over a 7-day period using a custom-built uniaxial tensile strain bioreactor were characterized in terms of matrix organization, cell viability, and musculoskeletal gene expression profiles. The results displayed that the collagen fibers of the loaded samples exhibited increased matrix directionality with an increase in strain values. Gene expression analyses demonstrated that ASC-encapsulated collagen scaffolds loaded at 2% strain and 0.1 Hz frequency showed significant increases in extracellular matrix genes and tenogenic differentiation markers. Importantly, no cross-differentiation potential to osteogenic, chondrogenic, and myogenic lineages was observed at 2% strain and 0.1 Hz frequency loading condition. Thus, 2% strain and 0.1 Hz frequency were identified as the appropriate mechanical loading regime to induce tenogenic differentiation of adipose-derived stem cells cultured in a three-dimensional environment.

  2. Effect of Uniaxial Tensile Cyclic Loading Regimes on Matrix Organization and Tenogenic Differentiation of Adipose-Derived Stem Cells Encapsulated within 3D Collagen Scaffolds.

    Science.gov (United States)

    Subramanian, Gayathri; Stasuk, Alexander; Elsaadany, Mostafa; Yildirim-Ayan, Eda

    2017-01-01

    Adipose-derived mesenchymal stem cells have become a popular cell choice for tendon repair strategies due to their relative abundance, ease of isolation, and ability to differentiate into tenocytes. In this study, we investigated the solo effect of different uniaxial tensile strains and loading frequencies on the matrix directionality and tenogenic differentiation of adipose-derived stem cells encapsulated within three-dimensional collagen scaffolds. Samples loaded at 0%, 2%, 4%, and 6% strains and 0.1 Hz and 1 Hz frequencies for 2 hours/day over a 7-day period using a custom-built uniaxial tensile strain bioreactor were characterized in terms of matrix organization, cell viability, and musculoskeletal gene expression profiles. The results displayed that the collagen fibers of the loaded samples exhibited increased matrix directionality with an increase in strain values. Gene expression analyses demonstrated that ASC-encapsulated collagen scaffolds loaded at 2% strain and 0.1 Hz frequency showed significant increases in extracellular matrix genes and tenogenic differentiation markers. Importantly, no cross-differentiation potential to osteogenic, chondrogenic, and myogenic lineages was observed at 2% strain and 0.1 Hz frequency loading condition. Thus, 2% strain and 0.1 Hz frequency were identified as the appropriate mechanical loading regime to induce tenogenic differentiation of adipose-derived stem cells cultured in a three-dimensional environment.

  3. In situ tensile testing of individual Co nanowires inside a scanning electron microscope

    International Nuclear Information System (INIS)

    Zhang Dongfeng; Breguet, Jean-Marc; Clavel, Reymond; Phillippe, Laetitia; Utke, Ivo; Michler, Johann

    2009-01-01

    Uniaxial quasi-static tensile testing on individual nanocrystalline Co nanowires (NWs), synthesized by electrochemical deposition process (EDP) in porous templates, was performed inside a scanning electron microscope (SEM) using a microfabricated tensile stage consisting of a comb drive actuator and a clamped-clamped beam force sensor. A 'three-beam structure' was fabricated by focused ion beam induced deposition (FIBID) on the stage, from which the specimen elongation and the tensile force could be measured simultaneously from SEM images at high magnification. A novel strategy of modifying device topography, e.g. in the form of trenches and pillars, was proposed to facilitate in situ SEM pick-and-place nanomanipulation, which could achieve a high yield of about 80% and reduce the difficulties in specimen preparation for tensile testing at the nanoscale. The measured apparent Young's modulus (75.3 ± 14.6) GPa and tensile strength (1.6 ± 0.4) GPa are significantly lower than the bulk modulus and the theoretical strength of monocrystalline samples, respectively. This result is important for designing Co NW-based devices. The origins of these distinctions are discussed in terms of the stiffnesses of the soldering portions, specimen misalignment, microstructure of the NWs and the experimental measurement uncertainty.

  4. Layer specific tensile testing of human arteries at the Austrian SAXS beamline at ELETTRA

    International Nuclear Information System (INIS)

    Schmid, F.; Rappolt, M.; Amenitsch, H.; Laggner, P.; Schulze-Bauer, C.A.; Sommer, G.; Holzapfel, G.A.; Regitnig, P.

    2005-01-01

    Full text: The collagen diffraction patterns of human aortas under uniaxial tensile test conditions have been investigated by synchrotron small angle x-ray diffraction. Using a recently designed tensile testing device, the orientation and d-spacing of the collagen fibers in the major arterial layers have been measured in situ under physiological conditions, together with the macroscopic force and sample stretching. The results show a direct relation between the orientation/extension of the collagen fibers on the nanoscopic level and the macroscopic stress and strain. This is attributed first to a straightening, second to a reorientation of the collagen fibers, and third to an uptaKEX of the increasing loads by the collagen fibers. (author)

  5. Optimization of tensile method and specimen geometry in modified ring tensile test

    International Nuclear Information System (INIS)

    Kitano, Koji; Fuketa, Toyoshi; Sasajima, Hideo; Uetsuka, Hiroshi

    2001-03-01

    Several techniques in ring tensile test are proposed in order to evaluate mechanical properties of cladding under hoop loading condition caused by pellet/cladding mechanical interaction (PCMI). In the modified techniques, variety of tensile methods and specimen geometry are being proposed in order to limit deformation within the gauge section. However, the tensile method and the specimen geometry were not determined in the modified techniques. In the present study, we have investigated the tensile method and the specimen geometry through finite element method (FEM) analysis of specimen deformation and tensile test on specimens with various gauge section geometries. In using two-piece tensile tooling, the mechanical properties under hoop loading condition can be correctly evaluated when deformation part (gauge section) is put on the top of a half-mandrel, and friction between the specimen and the half-mandrel is reduced with Teflon tape. In addition, we have shown the optimum specimen geometry for PWR 17 by 17 type cladding. (author)

  6. New Scanning Electron Microscope Used for Cryogenic Tensile Testing

    CERN Multimedia

    Maximilien Brice

    2013-01-01

    At CERN engineering department's installation for cryogenic tensile testing, the new scanning electron microscope (SEM) allows for detailed optical observations to be carried out. Using the SEM, surface coatings and tensile properties of materials can investigated in order to better understand how they behave under different conditions.

  7. Use of run statistics to validate tensile tests

    International Nuclear Information System (INIS)

    Eatherly, W.P.

    1981-01-01

    In tensile testing of irradiated graphites, it is difficult to assure alignment of sample and train for tensile measurements. By recording location of fractures, run (sequential) statistics can readily detect lack of randomness. The technique is based on partitioning binomial distributions

  8. Polystyrene cryostat facilitates testing tensile specimens under liquid nitrogen

    Science.gov (United States)

    Shogan, R. P.; Skalka, R. J.

    1967-01-01

    Lightweight cryostat made of expanded polystyrene reduces eccentricity in a tensile system being tested under liquid nitrogen. The cryostat is attached directly to the tensile system by a special seal, reducing misalignment effects due to cryostat weight, and facilitates viewing and loading of the specimens.

  9. Stress distribution and lattice distortions in Nb3Sn multifilament wires under uniaxial tensile loading at 4.2 K

    International Nuclear Information System (INIS)

    Scheuerlein, C; Flükiger, R; Kadar, J; Bordini, B; Ballarino, A; Bottura, L; Di Michiel, M; Buta, F; Seeber, B; Senatore, C; Siegrist, T; Besara, T

    2014-01-01

    The lattice parameter changes in three types of Nb 3 Sn superconducting wires during uniaxial stress–strain measurements at 4.2 K have been measured by high-energy synchrotron x-ray diffraction. The nearly-stress-free Nb 3 Sn lattice parameter has been determined using extracted filaments, and the elastic strain in the axial and transverse wire directions in the different wire phases has been calculated. The mechanical properties of the PIT and RRP wire are mainly determined by the properties of Nb 3 Sn and unreacted Nb. This is in contrast to the bronze route wire, where the matrix can carry substantial loads. In straight wires the axial Nb 3 Sn pre-strain is strongest in the bronze route wire, its value being smaller in the PIT and RRP wires. A strong reduction of the non-Cu elastic modulus of about 30% is observed during cool-down from ambient temperature to 4.2 K. The Nb 3 Sn Poisson ratio at 4.2 K measured in the untwisted bronze route wire is 0.35. The present study also shows that the process route has a strong influence on the Nb 3 Sn texture. (paper)

  10. Elevated Temperature Tensile Tests on DU–10Mo Rolled Foils

    Energy Technology Data Exchange (ETDEWEB)

    Schulthess, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    Tensile mechanical properties for uranium-10 wt.% molybdenum (U–10Mo) foils are required to support modeling and qualification of new monolithic fuel plate designs. It is expected that depleted uranium-10 wt% Mo (DU–10Mo) mechanical behavior is representative of the low enriched U–10Mo to be used in the actual fuel plates, therefore DU-10Mo was studied to simplify material processing, handling, and testing requirements. In this report, tensile testing of DU-10Mo fuel foils prepared using four different thermomechanical processing treatments were conducted to assess the impact of foil fabrication history on resultant tensile properties.

  11. Study of tensile test behavior of austenitic stainless steel type 347 seamless thin-walled tubes in cold worked condition

    Energy Technology Data Exchange (ETDEWEB)

    Terui, Clarice, E-mail: clarice.terui@marinha.mil.br [Centro Tecnológico da Marinha em São Paulo (CINA/CTMSP), Iperó, SP (Brazil). Centro Industrial Nuclear da Marinha; Lima, Nelson B. de, E-mail: nblima@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNE-SP), Sao Paulo, SP (Brazil)

    2017-07-01

    These austenitic stainless steel type 347 seamless thin-walled tubes are potential candidates to be used in fuel elements of nuclear power plants (as PWR - Pressurized Water Reactor). So, their metallurgical condition and mechanical properties, as the tensile strength and yield strength, normally are very restrict in demanding project and design requirements. Several full size tensile tests at room temperature and high temperature (315 deg C) were performed in these seamless tubes in cold-worked condition. The results of specified tensile and yield strengths were achieved but the elongation of the tube, in the geometry of the component, could not be measured at high temperature due to unconventional mode of rupture (helical mode without separation of parts). The average value of elongation was obtained from stress-strain curves of hot tensile tests and was around 5%. The results obtained in this research show that this behavior of the full size tensile test samples of thin-walled tube (wall thickness less than 0.5 mm) in high temperature (315°C) is due to the combination of the manufacturing process, the material (crystallographic structure and chemical composition) and the final geometry of the component. In other words, the strong crystallographic texture of material induced by tube drawing process in addition with the geometry of the component are responsible for the behavior in hot uniaxial tensile tests. (author)

  12. Strain transfer through film-substrate interface and surface curvature evolution during a tensile test

    Science.gov (United States)

    He, Wei; Han, Meidong; Goudeau, Philippe; Bourhis, Eric Le; Renault, Pierre-Olivier; Wang, Shibin; Li, Lin-an

    2018-03-01

    Uniaxial tensile tests on polyimide-supported thin metal films are performed to respectively study the macroscopic strain transfer through an interface and the surface curvature evolution. With a dual digital image correlation (DIC) system, the strains of the film and the substrate can be simultaneously measured in situ during the tensile test. For the true strains below 2% (far beyond the films' elastic limit), a complete longitudinal strain transfer is present irrespective of the film thickness, residual stresses and microstructure. By means of an optical surface profiler, the three-dimensional (3D) topography of film surface can be obtained during straining. As expected, the profile of the specimen center remains almost flat in the tensile direction. Nevertheless, a relatively significant curvature evolution (of the same order with the initial curvature induced by residual stresses) is observed along the transverse direction as a result of a Poisson's ratio mismatch between the film and the substrate. Furthermore, finite element method (FEM) has been performed to simulate the curvature evolution considering the geometric nonlinearity and the perfect strain transfer at the interface, which agrees well with the experimental results.

  13. A methodology to investigate size scale effects in crystalline plasticity using uniaxial compression testing

    International Nuclear Information System (INIS)

    Uchic, Michael D.; Dimiduk, Dennis M.

    2005-01-01

    A methodology for performing uniaxial compression tests on samples having micron-size dimensions is presented. Sample fabrication is accomplished using focused ion beam milling to create cylindrical samples of uniform cross-section that remain attached to the bulk substrate at one end. Once fabricated, samples are tested in uniaxial compression using a nanoindentation device outfitted with a flat tip, and a stress-strain curve is obtained. The methodology can be used to examine the plastic response of samples of different sizes that are from the same bulk material. In this manner, dimensional size effects at the micron scale can be explored for single crystals, using a readily interpretable test that minimizes imposed stretch and bending gradients. The methodology was applied to a single-crystal Ni superalloy and a transition from bulk-like to size-affected behavior was observed for samples 5 μm in diameter and smaller

  14. A novel method for estimating soil precompression stress from uniaxial confined compression tests

    DEFF Research Database (Denmark)

    Lamandé, Mathieu; Schjønning, Per; Labouriau, Rodrigo

    2017-01-01

    . Stress-strain curves were obtained by performing uniaxial, confined compression tests on undisturbed soil cores for three soil types at three soil water potentials. The new method performed better than the Gompertz fitting method in estimating precompression stress. The values of precompression stress...... obtained from the new method were linearly related to the maximum stress experienced by the soil samples prior to the uniaxial, confined compression test at each soil condition with a slope close to 1. Precompression stress determined with the new method was not related to soil type or dry bulk density......The concept of precompression stress is used for estimating soil strength of relevance to fieldtraffic. It represents the maximum stress experienced by the soil. The most recently developed fitting method to estimate precompression stress (Gompertz) is based on the assumption of an S-shape stress...

  15. Tensile tests of 2500-kip prestressing tendons for the PCRV

    International Nuclear Information System (INIS)

    Nicolayeff, V.

    1978-05-01

    A 2500-kip (11-MN) capacity prestressing tendon consisting of sixty 0.5-in. (12.7-mm) strands was designed and tested for General Atomic Company by VSL Corporation of Los Gatos, California. Results of the static tensile test described in this report, and of dynamic tensile tests conducted by VSL in 1968 and 1969, indicate that the tendon system satisfies the requirements of the ASME Boiler and Pressure Vessel Code, Section III, Division 2, and so can be used for prestressing concrete reactor vessels

  16. Accurate anisotropic material modelling using only tensile tests for hot and cold forming

    Science.gov (United States)

    Abspoel, M.; Scholting, M. E.; Lansbergen, M.; Neelis, B. M.

    2017-09-01

    Accurate material data for simulations require a lot of effort. Advanced yield loci require many different kinds of tests and a Forming Limit Curve (FLC) needs a large amount of samples. Many people use simple material models to reduce the effort of testing, however some models are either not accurate enough (i.e. Hill’48), or do not describe new types of materials (i.e. Keeler). Advanced yield loci describe the anisotropic materials behaviour accurately, but are not widely adopted because of the specialized tests, and data post-processing is a hurdle for many. To overcome these issues, correlations between the advanced yield locus points (biaxial, plane strain and shear) and mechanical properties have been investigated. This resulted in accurate prediction of the advanced stress points using only Rm, Ag and r-values in three directions from which a Vegter yield locus can be constructed with low effort. FLC’s can be predicted with the equations of Abspoel & Scholting depending on total elongation A80, r-value and thickness. Both predictive methods are initially developed for steel, aluminium and stainless steel (BCC and FCC materials). The validity of the predicted Vegter yield locus is investigated with simulation and measurements on both hot and cold formed parts and compared with Hill’48. An adapted specimen geometry, to ensure a homogeneous temperature distribution in the Gleeble hot tensile test, was used to measure the mechanical properties needed to predict a hot Vegter yield locus. Since for hot material, testing of stress states other than uniaxial is really challenging, the prediction for the yield locus adds a lot of value. For the hot FLC an A80 sample with a homogeneous temperature distribution is needed which is due to size limitations not possible in the Gleeble tensile tester. Heating the sample in an industrial type furnace and tensile testing it in a dedicated device is a good alternative to determine the necessary parameters for the FLC

  17. Shear instabilities in perfect bcc crystals during simulated tensile tests

    Czech Academy of Sciences Publication Activity Database

    Černý, M.; Šesták, P.; Pokluda, J.; Šob, Mojmír

    2013-01-01

    Roč. 87, č. 1 (2013), 014117/1-014117/4 ISSN 1098-0121 R&D Projects: GA ČR(CZ) GAP108/12/0311 Institutional support: RVO:68081723 Keywords : instabilities * tensile test * bcc metals * ab initio calculations Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.664, year: 2013

  18. Evaluation of microtensile and tensile bond strength tests ...

    African Journals Online (AJOL)

    Objectives: The aim of the present study was to compare two different bond strength test methods (tensile and microtensile) in investing the influence of erbium, chromium: yttrium‑scandium‑gallium‑garnet (Er, Cr: YSGG) laser pulse frequency on resin‑enamel bonding. Materials and Methods: One‑hundred and twenty‑five ...

  19. Tensile testing grips are easily assembled under liquid nitrogen

    Science.gov (United States)

    Skalka, R. J.; Vandergrift, E. F.

    1967-01-01

    Split-screw grips for tensile testing provide uniform loading on the specimen shoulders. Holes in the heads enable the screws and specimen to be threaded as an assembly into a grip body, closely controlled guides and seats afford positive seating, and precision machining of mating surfaces minimizes misalignment effects.

  20. Evaluation of microtensile and tensile bond strength tests ...

    African Journals Online (AJOL)

    2015-11-03

    Nov 3, 2015 ... Bond strength tests and Er,Cr:YSGG laser frequency. 586 ... power, 90% air pressure, 75% water pressure, 45 s irradiation ..... geometry on the measurement of the tensile bond strength to dentin. J Dent ... Bur‑cut enamel and.

  1. A Novel Geometry for Shear Test Using Axial Tensile Setup

    Directory of Open Access Journals (Sweden)

    Sibo Yuan

    2018-05-01

    Full Text Available This paper studies a novel geometry for the in-plane shear test performed with an axial electromechanical testing machine. In order to investigate the influence of the triaxiality rate on the mechanical behavior, different tests will be performed on the studied material: simple tensile tests, large tensile tests and shear tests. For the whole campaign, a common equipment should be employed to minimize the impact of the testing device. As a consequence, for the shear tests, the geometry of the specimen must be carefully designed in order to adapt the force value and make it comparable to the one obtained for the tensile tests. Like most of the existing shear-included tensile test specimens, the axial loading is converted to shear loading at a particular region through the effect of geometry. A symmetric shape is generally preferred, since it can restrict the in-plane rotation of the shear section, keep shear increasing in a more monotonic path and double the force level thanks to the two shear zones. Due to the specific experimental conditions, such as dimensions of the furnace and the clamping system, the position of the extensometer or the restriction of sheet thickness (related to the further studies of size effect at mesoscale and hot temperature, several geometries were brought up and evaluated in an iterative procedure via finite element simulations. Both the numerical and experimental results reveal that the final geometry ensures some advantages. For instance, a relatively low triaxiality in the shear zone, limited in-plane rotation and no necking are observed. Moreover, it also prevents any out-of-plane displacement of the specimen which seems to be highly sensitive to the geometry, and presents a very limited influence of the material and the thickness.

  2. Tensile and fracture toughness test results of neutron irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Chaouadi, R.; Moons, F.; Puzzolante, J.L. [Centre d`Etude de l`Energie Nucleaire, Mol (Belgium)

    1998-01-01

    Tensile and fracture toughness test results of four Beryllium grades are reported here. The flow and fracture properties are investigated by using small size tensile and round compact tension specimens. Irradiation was performed at the BR2 material testing reactor which allows various temperature and irradiation conditions. The fast neutron fluence (>1 MeV) ranges between 0.65 and 2.45 10{sup 21} n/cm{sup 2}. In the meantime, un-irradiated specimens were aged at the irradiation temperatures to separate if any the effect of temperature from irradiation damage. Test results are analyzed and discussed, in particular in terms of the effects of material grade, test temperature, thermal ageing and neutron irradiation. (author)

  3. Indigenous Design for Automatic Testing of Tensile Strength Using Graphical User Interface

    OpenAIRE

    Ali Rafay; Junejo Faraz; Imtiaz Rafey; Shamsi Usama Sultan

    2016-01-01

    Tensile Testing is a fundamental material test to measure the tenacity and tensile strength. Tensile strength means ability to take tensile stress. This Universal Testing Machine is designed using Dual Cylinder Technique in order to comply with the maximun load (tensile force) with the reduction of minimum physical effort and minimized losses.It is to provide material testing opportunity to the students of different institutions, locally and globally, at lowest price; so that they can have a ...

  4. Uniaxial ratcheting behavior of Zircaloy-4 tubes at room temperature

    International Nuclear Information System (INIS)

    Wen, Mingjian; Li, Hua; Yu, Dunji; Chen, Gang; Chen, Xu

    2013-01-01

    In this study, a series of uniaxial tensile, strain cycling and uniaxial ratcheting tests were conducted at room temperature on Zircaloy-4 (Zr-4) tubes used as nuclear fuel cladding in Pressurized Water Reactors (PWRs) for the purpose to investigate the uniaxial ratcheting behavior of Zr-4 and the factors which may influence it. The experimental results show that at room temperature this material features cyclic softening remarkably within the strain range of 1.6%, and former cycling under larger strain amplitude cannot retard cyclic softening of later cycling under lower strain amplitude. Uniaxial ratcheting strain accumulates in the direction of mean stress, and the ratcheting stain level is larger under tensile mean stress than that under compressive mean stress. Uniaxial ratcheting strain level increases with the increase of mean stress and stress amplitude, and decreases with the increase of loading rate. The sequence of loading rate appears to have no effects on the final ratcheting strain accumulation. Loading history has great influence on the uniaxial ratcheting behavior. Lower stress level after loading history with higher stress level leads to the shakedown of ratcheting. Higher loading rate after loading history with lower loading rate brings down the ratcheting strain rate. Uniaxial ratcheting behavior is sensitive to compressive pre-strain, and the decay rate of the ratcheting strain rate is slowed down by pre-compression

  5. Fracture toughness evaluation using circumferential notched tensile specimens by the tensile test and ANSYS software

    Energy Technology Data Exchange (ETDEWEB)

    Meydanlik, N. [Mechanical Engineering Department, Trakya University, Edirne (Turkey)

    2013-07-01

    Fracture toughness (K{sub Ic} ) is the most important parameter that defines mechanical behaviour of the materials using machine design. Since, fracture tests are both difficult and time consuming, the researchers have been investigating for the easier evaluation of K{sub Ic} for many years. In this work; K{sub Ic} values have been obtained by using ANSYS software based on the experimental values evaluated in the previous studies. It was shown that there is no significant difference between the experimental ones and the ones obtained by ANSYS. This procedure can provide an important advantage on obtaining of the K{sub IC} values. Key words: Fracture toughness (K{sub Ic} ), circumferential notched tensile specimens, ANSYS.

  6. Tensile and Flexural Test on Kenaf Hybrid Composites

    Science.gov (United States)

    Salleh, Z.; Yunus, S.; Masdek, N. R. N. M.; Taib, Y. M.; Azhar, I. I. S.; Hyie, K. M.

    2018-03-01

    The widely use of synthetic materials like carbon and fiberglass in various industries such as automotive and aircraft has lead to human health and environment problems. Therefore, the use of natural fibres such as kenaf has received higher attention as reinforcement. Kenaf or the scientific name is Hibiscus Cannabinus. L is one of the group of Malvecea plant which in the early days, the application of kenaf served only rope and canvas. However, it has more advantages than synthetic materials such as; widely availaible, renewable, lightweight, non-abbrasiveness during processing, high specific strength, free from health hazard and biodegradeable. This study was carried out to investigate the effects of different arrangement of kenaf and fiberglass composites on Young’s Modulus. The material composite was hardened with polyester resin and their properties was characterized. The tensile and the flexural properties is determined using an Instron universal tensile testing machine and carried out by following ASTM D3039 for tensile and ASTM D790 for a flexural test. The experimental program was designed to correlate the flexural and tensile Young’s Modulus of kenaf and fiberglass composite under the same load condition but different arrangement of kenaf and fiberglass on the mold . The resistance to change in shape was described by the behavior and characteristic of the composite materials. The stiffness or the elastic modulus of the composite material was determined at the end of the experiment. The results obtained show that the [±90FG/0/90/90/0/±90FG] kenaf/fiberglass composite arrangement has the highest elastic value.

  7. Nondestructive testing of the low-level radioactive waste drums for uni-axial compressive strength and free liquid content

    International Nuclear Information System (INIS)

    Yu Geping; Chang Mingyu; Wang Yeajeng; Chu, David S.L.; Ju Yihzen

    1992-01-01

    This paper summarizes the nondestructive test to determine the uni-axial compressive strength and free water content of solidified low level radioactive waste. The uni-axial compressive strength is determined by ultrasonic wave propagation speed, and the results are compared with those of compressive tests. Three methods of detecting the surface free water by ultrasonic testing are established, the ultrasonic wave speed, wave form and pulse height are used to determine the existence and amount of the surface free liquid. Possible difficulties are discussed. (author)

  8. Fracture assessment of shallow-flaw cruciform beams tested under uniaxial and biaxial loading conditions

    International Nuclear Information System (INIS)

    Bass, B.R.; McAfee, W.J.; Williams, P.T.; Pennell, W.E.

    1999-01-01

    A technology to determine shallow-flaw fracture toughness of reactor pressure vessel (RPV) steels is being developed for application to the safety assessment of RPVs containing postulated shallow surface flaws. Matrices of cruciform beam tests were developed to investigate and quantify the effects of temperature, biaxial loading, and specimen size on fracture initiation toughness of two-dimensional (constant depth), shallow, surface flaws. The cruciform beam specimens were developed at Oak Ridge National Laboratory (ORNL) to introduce a far-field, out-of-plane biaxial stress component in the test section that approximates the nonlinear stresses resulting from pressurized-thermal-shock or pressure-temperature loading of an RPV. Tests were conducted under biaxial load ratios ranging from uniaxial to equibiaxial. These tests demonstrated that biaxial loading can have a pronounced effect on shallow-flaw fracture toughness in the lower transition temperature region for an RPV material. The cruciform fracture toughness data were used to evaluate fracture methodologies for predicting the observed effects of biaxial loading on shallow-flaw fracture toughness. Initial emphasis was placed on assessment of stress-based methodologies, namely, the J-Q formulation, the Dodds-Anderson toughness scaling model, and the Weibull approach. Applications of these methodologies based on the hydrostatic stress fracture criterion indicated an effect of loading-biaxiality on fracture toughness; the conventional maximum principal stress criterion indicated no effect. A three-parameter Weibull model based on the hydrostatic stress criterion is shown to correlate with the experimentally observed biaxial effect on cleavage fracture toughness by providing a scaling mechanism between uniaxial and biaxial loading states. (orig.)

  9. Size Effect Studies on Tensile Tests for Hot Stamping Steel

    Science.gov (United States)

    Chen, Xiaodu; Li, Yuanyuan; Han, Xianhong; Zhang, Junbo

    2018-02-01

    Tensile tests have been widely used to determine basic mechanical properties of materials. However, the properties measured may be related to geometrical factors of the tested samples especially for high-strength steels; this makes the properties' definitions and comparisons difficult. In this study, a series of tensile tests of ultra-high-strength hot-stamped steel were performed; the geometric shapes and sizes as well as the cutting direction were modified. The results demonstrate that the hot-stamped parts were isotropic and the cutting direction had no effect; the measured strengths were practically unrelated to the specimen geometries, including both size and shape. The elongations were slightly related to sample sizes within the studied range but highly depended on the sample shape, represented by the coefficient K. Such phenomena were analyzed and discussed based on microstructural observations and fracture morphologies. Moreover, two widely used elongation conversion equations, the Oliver formula and Barba's law, were introduced to verify their applicability, and a new interpolating function was developed and compared.

  10. Data processing codes for fatigue and tensile tests

    International Nuclear Information System (INIS)

    Sanchez Sarmiento, Gustavo; Iorio, A.F.; Crespi, J.C.

    1981-01-01

    The processing of fatigue and tensile tests data in order to obtain several parameters of engineering interest requires a considerable effort of numerical calculus. In order to reduce the time spent in this work and to establish standard data processing from a set of similar type tests, it is very advantageous to have a calculation code for running in a computer. Two codes have been developed in FORTRAN language; one of them predicts cyclic properties of materials from the monotonic and incremental or multiple cyclic step tests (ENSPRED CODE), and the other one reduces data coming from strain controlled low cycle fatigue tests (ENSDET CODE). Two examples are included using Zircaloy-4 material from different manufacturers. (author) [es

  11. Tensile and Creep Testing of Sanicro 25 Using Miniature Specimens

    Science.gov (United States)

    Dymáček, Petr; Jarý, Milan; Dobeš, Ferdinand; Kloc, Luboš

    2018-01-01

    Tensile and creep properties of new austenitic steel Sanicro 25 at room temperature and operating temperature 700 °C were investigated by testing on miniature specimens. The results were correlated with testing on conventional specimens. Very good agreement of results was obtained, namely in yield and ultimate strength, as well as short-term creep properties. Although the creep rupture time was found to be systematically shorter and creep ductility lower in the miniature test, the minimum creep rates were comparable. The analysis of the fracture surfaces revealed similar ductile fracture morphology for both specimen geometries. One exception was found in a small area near the miniature specimen edge that was cut by electro discharge machining, where an influence of the steel fracture behavior at elevated temperature was identified. PMID:29337867

  12. Reversible temper brittleness on tensile tests at room temperature

    International Nuclear Information System (INIS)

    Quadros, N.F. de; Cabral, U.Q.

    1976-01-01

    Tensile tests were carried out on unnotched test pieces at room temperature and three strain rates: 2,5x10 -4 , 2,5x10 -3 and 1,0x10 -2 s -1 in a low alloy No-Cr-Mo steel to observe the variation in its mechanical properties with the occurrence of reversible temper brittleness. The brittle samples showed a sensitivity of 50 0 C in a 48 hour heat treatment at 500 0 C. The tests showed that at the strain rate of 2,5x10 -4 s -1 there are statistically significant differences between the elongations of the material in the brittle and the nonbrittle and regenerated states. A short review of reversible temper brittleness is given and a theory suggested for the mechanism [pt

  13. Tensile and Creep Testing of Sanicro 25 Using Miniature Specimens.

    Science.gov (United States)

    Dymáček, Petr; Jarý, Milan; Dobeš, Ferdinand; Kloc, Luboš

    2018-01-16

    Tensile and creep properties of new austenitic steel Sanicro 25 at room temperature and operating temperature 700 °C were investigated by testing on miniature specimens. The results were correlated with testing on conventional specimens. Very good agreement of results was obtained, namely in yield and ultimate strength, as well as short-term creep properties. Although the creep rupture time was found to be systematically shorter and creep ductility lower in the miniature test, the minimum creep rates were comparable. The analysis of the fracture surfaces revealed similar ductile fracture morphology for both specimen geometries. One exception was found in a small area near the miniature specimen edge that was cut by electro discharge machining, where an influence of the steel fracture behavior at elevated temperature was identified.

  14. Effects of strain rate, test temperature and test environment on tensile properties of vandium alloys

    International Nuclear Information System (INIS)

    Gubbi, A.N.; Rowcliffe, A.F.; Eatherly, W.S.; Gibson, L.T.

    1996-01-01

    Tensile testing was carried out on SS-3 tensile specimens punched from 0.762-mm-thick sheets of the large heat of V-4Cr-4Ti and small heats of V-3Cr-3Ti and V-6Cr-6Ti. The tensile specimens were annealed at 1000 degrees for 2 h to obtain a fully recrystallized, fine grain microstructure with a grain size in the range of 10-19 μm. Room temperature tests at strain rates ranging from 10 -3 to 5 x 10 -1 /s were carried out in air; elevated temperature testing up to 700 degrees C was conducted in a vacuum better than 1 x 10 -5 torr ( -3 Pa). To study the effect of atomic hydrogen on ductility, tensile tests were conducted at room temperature in an ultra high vacuum chamber (UHV) with a hydrogen leak system

  15. Effects of strain rate, test temperature and test environment on tensile properties of vandium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gubbi, A.N.; Rowcliffe, A.F.; Eatherly, W.S.; Gibson, L.T. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    Tensile testing was carried out on SS-3 tensile specimens punched from 0.762-mm-thick sheets of the large heat of V-4Cr-4Ti and small heats of V-3Cr-3Ti and V-6Cr-6Ti. The tensile specimens were annealed at 1000{degrees} for 2 h to obtain a fully recrystallized, fine grain microstructure with a grain size in the range of 10-19 {mu}m. Room temperature tests at strain rates ranging from 10{sup {minus}3} to 5 x 10{sup {minus}1}/s were carried out in air; elevated temperature testing up to 700{degrees}C was conducted in a vacuum better than 1 x 10{sup {minus}5} torr (<10{sup {minus}3} Pa). To study the effect of atomic hydrogen on ductility, tensile tests were conducted at room temperature in an ultra high vacuum chamber (UHV) with a hydrogen leak system.

  16. Cyclic mechanical behavior of 316L: Uniaxial LCF and strain-controlled ratcheting tests

    International Nuclear Information System (INIS)

    Facheris, G.; Janssens, K.G.F.

    2013-01-01

    Highlights: ► Characterization of cyclic plastic deformation behavior of plate and tubular 316L. ► Strain-controlled ratcheting response between room temperature and 200 °C. ► Isotropic cyclic hardening is dependent on the yield criterion used. ► Ratcheting induced hardening mostly affects the kinematic hardening component. ► Ratcheting induced hardening is related to the mean strain and the ratcheting rate. -- Abstract: With the purpose of analyzing the fatigue behavior under loading conditions relevant for the primary cooling circuit of a light water nuclear reactor, a set of uniaxial low cycle fatigue and strain-controlled ratcheting tests (also named ‘cyclic tension tests’) has been performed at room temperature and at 200 °C on specimens manufactured from two different batches of stainless steel grade 316L. The experiments have been repeated varying strain amplitude, cyclic ratcheting rate and ratcheting direction in order to investigate the influence on the cyclic deformation behavior. In strain-controlled ratcheting tests, the stress response is found to be a superposition of two hardening mechanisms: the first one due to the zero mean strain cycling and the second one linked with the monotonic drifting of mean plastic strain. An approach is proposed to distinguish the effect of each mechanism and the influence of the test parameters on the hardening mechanisms is discussed

  17. Generation of uniaxial tensile strain of over 1% on a Ge substrate for short-channel strained Ge n-type Metal–Insulator–Semiconductor Field-Effect Transistors with SiGe stressors

    International Nuclear Information System (INIS)

    Moriyama, Yoshihiko; Kamimuta, Yuuichi; Ikeda, Keiji; Tezuka, Tsutomu

    2012-01-01

    Tensile strain of over 1% in Ge stripes sandwiched between a pair of SiGe source-drain stressors was demonstrated. The Metal–Oxide–Semiconductor Field-Effect Transistor (MOSFET)-like structures were fabricated on a (001)-Ge substrate having SiO 2 dummy-gate stripes with widths down to 26 nm. Recess-regions adjacent to the dummy-gate stripes were formed by an anisotropic wet etching technique. A damage-free and well-controlled anisotropic wet etching process is developed in order to avoid plasma-induced damage during a conventional Reactive-ion Etching process. The SiGe stressors were epitaxially grown on the recesses to simulate strained Ge n-channel Metal–Insulator–Semiconductor Field-Effect Transistors (MISFETs) having high electron mobility. A micro-Raman spectroscopy measurement revealed tensile strain in the narrow Ge regions which became higher for narrower regions. Tensile strain of up to 1.2% was evaluated from the measurement under an assumption of uniaxial strain configuration. These results strongly suggest that higher electron mobility than the upper limit for a Si-MOSFET is obtainable in short-channel strained Ge-nMISFETs with the embedded SiGe stressors.

  18. Miniature tensile test specimens for fusion reactor irradiation studies

    International Nuclear Information System (INIS)

    Klueh, R.L.

    1985-01-01

    Three miniature sheet-type tensile specimens and a miniature rod-type specimen are being used to determine irradiated tensile properties for alloy development for fusion reactors. The tensile properties of type 316 stainless steel were determined with these different specimens, and the results were compared. Reasonably good agreement was observed. However, there were differences that led to recommendations on which specimens are preferred. 4 references, 9 figures, 6 tables

  19. In-Situ tensile testing of propellants in SEM: influence of temperature

    NARCIS (Netherlands)

    Di Benedetto, G.L.; Ramshorst, M.C.J.; Duvalois, W.; Hooijmeijer, P.; Heijden, A. van der

    2017-01-01

    A tensile module system placed within a Scanning Electron Microscope (SEM) was utilized to conduct insitu tensile testing of propellant samples. The tensile module system allows for real-time in-situ SEM analysis of the samples to determine the failure mechanism of the propellant material under

  20. Acoustic Emission from Elevator Wire Ropes During Tensile Testing

    Science.gov (United States)

    Bai, Wenjie; Chai, Mengyu; Li, Lichan; Li, Yongquan; Duan, Quan

    The acoustic emission (AE) technique was used to monitor the tensile testing process for two kinds of elevator wire ropes in our work. The AE signals from wire breaks were obtained and analyzed by AE parameters and waveforms. The results showed that AE technique can be a useful tool to monitor wire break phenomenon of wire ropes and effectively capture information of wire break signal. The relationship between AE signal characteristics and wire breaks is investigated and it is found that the most effective acoustic signal discriminators are amplitude and absolute energy. Moreover, the wire break signal of two kinds of ropes is a type of burst signal and it is believed that the waveform and spectrum can be applied to analyze the AE wire break signals.

  1. Experimental Study of Tensile Test in Resistance Spot Welding Process

    Directory of Open Access Journals (Sweden)

    Lebbal Habib

    Full Text Available Abstract Resistance spot welding (RSW is a widely used joining process for fabricating sheet metal assemblies in automobile industry .In comparison with other welding processes the RSW is faster and easier for automation. This process involves electrical, thermal and mechanical interactions. Resistance spot welding primarily takes place by localized melting spot at the interface of the sheets followed by its quick solidification under sequential control of pressure water-cooled electrode and flow of required electric current for certain duration. In this work the tensile tests were studied, the results obtained show that the type material, the overlap length, the angle of the rolling direction and the thickness of the sheet have an influence in resistance spot welding process.

  2. A new laser reflectance system capable of measuring changing cross-sectional area of soft tissues during tensile testing.

    Science.gov (United States)

    Pokhai, Gabriel G; Oliver, Michele L; Gordon, Karen D

    2009-09-01

    Determination of the biomechanical properties of soft tissues such as tendons and ligaments is dependent on the accurate measurement of their cross-sectional area (CSA). Measurement methods, which involve contact with the specimen, are problematic because soft tissues are easily deformed. Noncontact measurement methods are preferable in this regard, but may experience difficulty in dealing with the complex cross-sectional shapes and glistening surfaces seen in soft tissues. Additionally, existing CSA measurement systems are separated from the materials testing machine, resulting in the inability to measure CSA during testing. Furthermore, CSA measurements are usually made in a different orientation, and with a different preload, prior to testing. To overcome these problems, a noncontact laser reflectance system (LRS) was developed. Designed to fit in an Instron 8872 servohydraulic test machine, the system measures CSA by orbiting a laser transducer in a circular path around a soft tissue specimen held by tissue clamps. CSA measurements can be conducted before and during tensile testing. The system was validated using machined metallic specimens of various shapes and sizes, as well as different sizes of bovine tendons. The metallic specimens could be measured to within 4% accuracy, and the tendons to within an average error of 4.3%. Statistical analyses showed no significant differences between the measurements of the LRS and those of the casting method, an established measurement technique. The LRS was successfully used to measure the changing CSA of bovine tendons during uniaxial tensile testing. The LRS developed in this work represents a simple, quick, and accurate way of reconstructing complex cross-sectional profiles and calculating cross-sectional areas. In addition, the LRS represents the first system capable of automatically measuring changing CSA of soft tissues during tensile testing, facilitating the calculation of more accurate biomechanical properties.

  3. Impact Tensile Testing of Stainless Steels at Various Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    D. K. Morton

    2008-03-01

    Stainless steels are used for the construction of numerous spent nuclear fuel or radioactive material containers that may be subjected to high strains and moderate strain rates during accidental drop events. Mechanical characteristics of these base materials and their welds under dynamic loads in the strain rate range of concern (1 to 300 per second) are not well documented. However, research is being performed at the Idaho National Laboratory to quantify these characteristics. The work presented herein discusses tensile impact testing of dual-marked 304/304L and 316/316L stainless steel material specimens. Both base material and welded material specimens were tested at -20 oF, room temperature, 300 oF, and 600 oF conditions. Utilizing a drop weight impact test machine and 1/4-inch and 1/2-inch thick dog bone-shaped test specimens, a strain rate range of approximately 4 to 40 per second (depending on initial temperature conditions) was achieved. Factors were determined that reflect the amount of increased strain energy the material can absorb due to strain rate effects. Using the factors, elevated true stress-strain curves for these materials at various strain rates and temperatures were generated. By incorporating the strain rate elevated true stress-strain material curves into an inelastic finite element computer program as the defined material input, significant improvement in the accuracy of the computer analyses was attained. However, additional impact testing is necessary to achieve higher strain rates (up to 300 per second) before complete definition of strain rate effects can be made for accidental drop events and other similar energy-limited impulsive loads. This research approach, using impact testing and a total energy analysis methodology to quantify strain rate effects, can be applied to many other materials used in government and industry.

  4. Relationship between surface area for adhesion and tensile bond strength--evaluation of a micro-tensile bond test.

    Science.gov (United States)

    Sano, H; Shono, T; Sonoda, H; Takatsu, T; Ciucchi, B; Carvalho, R; Pashley, D H

    1994-07-01

    The purpose of this study was to test the null hypothesis that there is no relationship between the bonded surface area of dentin and the tensile strength of adhesive materials. The enamel was removed from the occlusal surface of extracted human third molars, and the entire flat surface was covered with resin composite bonded to the dentin to form a flat resin composite crown. Twenty-four hours later, the bonded specimens were sectioned parallel to the long axis of the tooth into 10-20 thin sections whose upper part was composed of resin composite with the lower half being dentin. These small sections were trimmed using a high speed diamond bur into an hourglass shape with the narrowest portion at the bonded interface. Surface area was varied by altering the specimen thickness and width. Tensile bond strength was measured using custom-made grips in a universal testing machine. Tensile bond strength was inversely related to bonded surface area. At surface areas below 0.4 mm2, the tensile bond strengths were about 55 MPa for Clearfil Liner Bond 2 (Kuraray Co., Ltd.), 38 MPa for Scotchbond MP (3M Dental Products), and 20 MPa for Vitremer (3M Dental Products). At these small surface areas all of the bond failures were adhesive in nature. This new method permits measurement of high bond strengths without cohesive failure of dentin. It also permits multiple measurements to be made within a single tooth.

  5. A study on stress analysis of small punch-creep test and its experimental correlations with uniaxial-creep test

    International Nuclear Information System (INIS)

    Lee, Song In; Baek, Seoung Se; Kwon, Il Hyun; Yu, Hyo Sun

    2002-01-01

    A basic research was performed to ensure the usefulness of Small Punch-creep(SP-creep) test for residual life evaluation of heat resistant components effectively. This paper presents analytical results of initial stress and strain distributions in SP specimen caused by constant loading for SP-creep test and its experimental correlations with uniaxial creep(Ten-creep) test on 9CrlMoVNb steel. It was shown that the initial maximum equivalent stress, σ eq · max from FE analysis was correlated with steady-state equivalent creep strain rate, ε qf-ss , rupture time, t r , activation energy, Q and Larson-Miller parameter, LMP during SP-creep deformation. The simple correlation laws, σ SP - σ TEN , P SP -σ TEN and Q SP -Q TEN adopted to established a quantitative correlation between SP-creep and Ten-creep test data. Especially, the activation energy obtained from SP-creep test is linearly related to that from Ten-creep test at 650 deg. C as follows : Q SP-P =1.37 Q TEN , Q SP-σ =1.53 Q TEN

  6. Micro/nano-mechanical test system employing tensile test holder with push-to-pull transformer

    Science.gov (United States)

    Oh, Yunje; Cyrankowski, Edward; Shan, Zhiwei; Asif, Syed Amanula Syed

    2013-05-07

    A micromachined or microelectromechanical system (MEMS) based push-to-pull mechanical transformer for tensile testing of micro-to-nanometer scale material samples including a first structure and a second structure. The second structure is coupled to the first structure by at least one flexible element that enables the second structure to be moveable relative to the first structure, wherein the second structure is disposed relative to the first structure so as to form a pulling gap between the first and second structures such that when an external pushing force is applied to and pushes the second structure in a tensile extension direction a width of the pulling gap increases so as to apply a tensile force to a test sample mounted across the pulling gap between a first sample mounting area on the first structure and a second sample mounting area on the second structure.

  7. Tensile strength of concrete under static and intermediate strain rates: Correlated results from different testing methods

    International Nuclear Information System (INIS)

    Wu Shengxing; Chen Xudong; Zhou Jikai

    2012-01-01

    Highlights: ► Tensile strength of concrete increases with increase in strain rate. ► Strain rate sensitivity of tensile strength of concrete depends on test method. ► High stressed volume method can correlate results from various test methods. - Abstract: This paper presents a comparative experiment and analysis of three different methods (direct tension, splitting tension and four-point loading flexural tests) for determination of the tensile strength of concrete under low and intermediate strain rates. In addition, the objective of this investigation is to analyze the suitability of the high stressed volume approach and Weibull effective volume method to the correlation of the results of different tensile tests of concrete. The test results show that the strain rate sensitivity of tensile strength depends on the type of test, splitting tensile strength of concrete is more sensitive to an increase in the strain rate than flexural and direct tensile strength. The high stressed volume method could be used to obtain a tensile strength value of concrete, free from the influence of the characteristics of tests and specimens. However, the Weibull effective volume method is an inadequate method for describing failure of concrete specimens determined by different testing methods.

  8. Research on Design and Simulation of Biaxial Tensile-Bending Complex Mechanical Performance Test Apparatus

    Directory of Open Access Journals (Sweden)

    Hailian Li

    2017-09-01

    Full Text Available In order to realize a micro-mechanic performance test of biaxial tensile-bending-combined loading and solve the problem of incompatibility of test apparatus and observation apparatus, novel biaxial-combined tensile-bending micro-mechanical performance test apparatus was designed. The working principle and major functions of key constituent parts of test apparatus, including the servo drive unit, clamping unit and test system, were introduced. Based on the finite element method, biaxial tensile and tension-bending-combined mechanical performances of the test-piece were studied as guidance to learn the distribution of elastic deformation and plastic deformation of all sites of the test-piece and to better plan test regions. Finally, this test apparatus was used to conduct a biaxial tensile test under different pre-bending loading and a tensile test at different rates; the image of the fracture of the test-piece was acquired by a scanning electron microscope and analyzed. It was indicated that as the pre-bending force rises, the elastic deformation phase would gradually shorten and the slope of the elastic deformation phase curve would slightly rise so that a yield limit would appear ahead of time. Bending speed could exert a positive and beneficial influence on tensile strength but weaken fracture elongation. If bending speed is appropriately raised, more ideal anti-tensile strength could be obtained, but fracture elongation would decline.

  9. Uniaxial backfill block compaction

    International Nuclear Information System (INIS)

    Koskinen, V.

    2012-05-01

    The main parts of the project were: to make a literature survey of the previous uniaxial compaction experiments; do uniaxial compaction tests in laboratory scale; and do industrial scale production tests. Object of the project was to sort out the different factors affecting the quality assurance chain of the backfill block uniaxial production and solve a material sticking to mould problem which appeared during manufacturing the blocks of bentonite and cruched rock mixture. The effect of mineralogical and chemical composition on the long term functionality of the backfill was excluded from the project. However, the used smectite-rich clays have been tested for mineralogical consistency. These tests were done in B and Tech OY according their SOPs. The objective of the Laboratory scale tests was to find right material- and compaction parameters for the industrial scale tests. Direct comparison between the laboratory scale tests and industrial scale tests is not possible because the mould geometry and compaction speed has a big influence for the compaction process. For this reason the selected material parameters were also affected by the previous compaction experiments. The industrial scale tests were done in summer of 2010 in southern Sweden. Blocks were done with uniaxial compaction. A 40 tons of the mixture of bentonite and crushed rock blocks and almost 50 tons of Friedland-clay blocks were compacted. (orig.)

  10. Experimental investigation of the strength and failure behavior of layered sandstone under uniaxial compression and Brazilian testing

    Science.gov (United States)

    Yin, Peng-Fei; Yang, Sheng-Qi

    2018-05-01

    As a typical inherently anisotropic rock, layered sandstones can differ from each other in several aspects, including grain size, type of material, type of cementation, and degree of compaction. An experimental study is essential to obtain and convictive evidence to characterize the mechanical behavior of such rock. In this paper, the mechanical behavior of a layered sandstone from Xuzhou, China, is investigated under uniaxial compression and Brazilian test conditions. The loading tests are conducted on 7 sets of bedding inclinations, which are defined as the angle between the bedding plane and horizontal direction. The uniaxial compression strength (UCS) and elastic modulus values show an undulatory variation when the bedding inclination increases. The overall trend of the UCS and elastic modulus values with bedding inclination is decreasing. The BTS value decreases with respect to the bedding inclination and the overall trend of it is approximating a linear variation. The 3D digital high-speed camera images reveal that the failure and fracture of a specimen are related to the surface deformation. Layered sandstone tested under uniaxial compression does not show a typical failure mode, although shear slip along the bedding plane occurs at high bedding inclinations. Strain gauge readings during the Brazilian tests indicate that the normal stress on the bedding plane transforms from compression to tension as the bedding inclination increases. The stress parallel to the bedding plane in a rock material transforms from tension to compression and agrees well with the fracture patterns; "central fractures" occur at bedding inclinations of 0°-75°, "layer activation" occurs at high bedding inclinations of 75°-90°, and a combination of the two occurs at 75°.

  11. Soft computing methods for estimating the uniaxial compressive strength of intact rock from index tests

    Czech Academy of Sciences Publication Activity Database

    Mishra, A. Deepak; Srigyan, M.; Basu, A.; Rokade, P. J.

    2015-01-01

    Roč. 80, December 2015 (2015), s. 418-424 ISSN 1365-1609 Institutional support: RVO:68145535 Keywords : uniaxial compressive strength * rock indices * fuzzy inference system * artificial neural network * adaptive neuro-fuzzy inference system Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 2.010, year: 2015 http://ac.els-cdn.com/S1365160915300708/1-s2.0-S1365160915300708-main.pdf?_tid=318a7cec-8929-11e5-a3b8-00000aacb35f&acdnat=1447324752_2a9d947b573773f88da353a16f850eac

  12. Mechanical Properties of Commercial Carbon Fibers Using a Single Filament Tensile Test

    International Nuclear Information System (INIS)

    Joh, Han-Ik; Song, Hae Kyung; Ku, Bon-Cheol; Lee, Sungho; Kim, Ki-Young; Kang, Phil-Hyun

    2013-01-01

    In this study, mechanical properties of commercial carbon fibers were evaluated using a single filament tensile test with various fiber gauge lengths. Tensile strength increased significantly with a decreasing length of the test specimens possibly due to small defect sites. The compliance method provided more accurate moduli of the carbon fibers, removing system errors during the single filament tensile test. The Weibull modulus revealed that shorter specimens had an inhomogeneous defect distribution, leading to a higher tensile strength and its standard deviation. X-ray diffractograms of carbon fibers showed a similar crystallinity and orientation in spite of significant differences in the fiber modulus and strength, indicating that crystalline structure of the commercial carbon fibers used in the study was not attributable to the difference in their tensile properties.

  13. Metallographic examinations of Type 304 stainless steel (heat 9T2796) tested in high-temperature uniaxial and multiaxial experiments

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W.; Houck, C.W.

    1984-03-01

    The results obtained from a number of metallographic examinations of Type 304 stainless steel specimens were compiled. Samples were obtained from uniaxial and multiaxial tests covering a very broad span of temperatures and times. Special emphasis was on the identification of failure modes, cracking patterns, grain distortion, and grain-boundary microstructures. Uniaxial specimens exhibited the following sequence of failure modes with increasing temperature and time: ductile plastic tearing, ductile plastic shear, wedge cracking, and microvoid cracking. Over most of the temperature range examined (482 to 871/sup 0/C), M/sub 23/C/sub 6/ precipitated on grain boundaries at long times. Sigma phase and possibly ferrite were often present in the stressed areas at temperatures as low as 482/sup 0/C (900/sup 0/F). These metallurgical features promoted a severe loss in creep ductility at long times and low temperatures. Most multiaxial tests were performed under conditions that promoted wedge cracking. Stress gradients also favored surface crack initiation rather than bulk damage. Testing times for multiaxial tests were less than 10,000 h; hence, there was insufficient time for the development of embrittling features such as microvoids, sigma, and ferrite. Long-time multiaxial tests to failure are recommended.

  14. A cryogenic tensile testing apparatus for micro-samples cooled by miniature pulse tube cryocooler

    International Nuclear Information System (INIS)

    Chen, L B; Liu, S X; Gu, K X; Zhou, Y; Wang, J J

    2015-01-01

    This paper introduces a cryogenic tensile testing apparatus for micro-samples cooled by a miniature pulse tube cryocooler. At present, tensile tests are widely applied to measure the mechanical properties of materials; most of the cryogenic tensile testing apparatus are designed for samples with standard sizes, while for non-standard size samples, especially for microsamples, the tensile testing cannot be conducted. The general approach to cool down the specimens for tensile testing is by using of liquid nitrogen or liquid helium, which is not convenient: it is difficult to keep the temperature of the specimens at an arbitrary set point precisely, besides, in some occasions, liquid nitrogen, especially liquid helium, is not easily available. To overcome these limitations, a cryogenic tensile testing apparatus cooled by a high frequency pulse tube cryocooler has been designed, built and tested. The operating temperatures of the developed tensile testing apparatus cover from 20 K to room temperature with a controlling precision of ±10 mK. The apparatus configurations, the methods of operation and some cooling performance will be described in this paper. (paper)

  15. Tensile-Creep Test Specimen Preparation Practices of Surface Support Liners

    Science.gov (United States)

    Guner, Dogukan; Ozturk, Hasan

    2017-12-01

    Ground support has always been considered as a challenging issue in all underground operations. Many forms of support systems and supporting techniques are available in the mining/tunnelling industry. In the last two decades, a new polymer based material, Thin Spray-on Liner (TSL), has attained a place in the market as an alternative to the current areal ground support systems. Although TSL provides numerous merits and has different application purposes, the knowledge on mechanical properties and performance of this material is still limited. In laboratory studies, since tensile rupture is the most commonly observed failure mechanism in field applications, researchers have generally studied the tensile testing of TSLs with modification of American Society for Testing and Materials (ASTM) D-638 standards. For tensile creep testing, specimen preparation process also follows the ASTM standards. Two different specimen dimension types (Type I, Type IV) are widely preferred in TSL tensile testing that conform to the related standards. Moreover, molding and die cutting are commonly used specimen preparation techniques. In literature, there is a great variability of test results due to the difference in specimen preparation techniques and practices. In this study, a ductile TSL product was tested in order to investigate the effect of both specimen preparation techniques and specimen dimensions under 7-day curing time. As a result, ultimate tensile strength, tensile yield strength, tensile modulus, and elongation at break values were obtained for 4 different test series. It is concluded that Type IV specimens have higher strength values compared to Type I specimens and moulded specimens have lower results than that of prepared by using die cutter. Moreover, specimens prepared by molding techniques have scattered test results. Type IV specimens prepared by die cutter technique are suggested for preparation of tensile test and Type I specimens prepared by die cutter technique

  16. Development of a miniature tensile Kolsky bar for dynamic testing of thin films

    Science.gov (United States)

    Paul, Jastin V.

    Mechanical properties such as yield stress and ultimate strength are most commonly obtained under quasi-static (strain rate of 10--4 s--1) loading conditions Materials such as metals, ceramics, and polymers may exhibit significant changes in mechanical response when subjected to high strain rate (102 --105 per second) conditions. The loading rate or strain rate can affect the material properties such as elastic modulus, yield strength, work hardening, and ductility. To ensure product quality and reliability under impact conditions, the mechanical responses of materials under dynamic loading conditions must be characterized. A Kolsky bar is a tool that can be used to study the uniaxial compressive constitutive behavior of materials under high strain rates. The goal of this thesis is to develop a miniature Tensile Kolsky bar that can be used to test materials with thickness on the order of 200 micrometers (thin foils). The system consists of a cylindrical launch tube with an internal striker, a rectangular incident bar and a transmitted bar. The specimen is held in pockets that were milled directly into the incident and transmitted bar. The rectangular incident and transmitted bars facilitate specimen and strain gage mounting. The rectangular section also provides a reduced cross sectional bar area compared to a bar of circular cross section with diameter equivalent to the width of the rectangular bar, which increases the system sensitivity. This thesis presents the detailed description of the miniature Kolsky bar device, specimen geometry, diagnostic techniques and different calibration and validation techniques used for developing the system. The Kolsky bar setup was used to test 99.9 percent pure magnesium at two different strain rates (5000 and 10000 per second). Specimens were cut from billets processed via the 4Bc equal channel angular extrusion route and were tested in three different directions: extrusion, longitudinal and transverse. The results from the

  17. High temperature tensile testing of modified 9Cr-1Mo after irradiation with high energy protons

    International Nuclear Information System (INIS)

    Toloczko, M.B.; Hamilton, M.L.; Maloy, S.A.

    2003-01-01

    This study examines the effect of tensile test temperatures ranging from 50 to 600 deg. C on the tensile properties of a modified 9Cr-1Mo ferritic steel after high energy proton irradiation at about 35-67 deg. C to doses from 1 to 3 dpa and 9 dpa. For the specimens irradiated to doses between 1 and 3 dpa, it was observed that the yield strength and ultimate strength decreased monotonically as a function of tensile test temperature, whereas the uniform elongation (UE) remained at approximately 1% for tensile test temperatures up to 250 deg. C and then increased for tensile test temperatures up to and including 500 deg. C. At 600 deg. C, the UE was observed to be less than the values at 400 and 500 deg. C. UE of the irradiated material tensile tested at 400-600 deg. C was observed to be greater than the values for the unirradiated material at the same temperatures. Tensile tests on the 9 dpa specimens followed similar trends

  18. Development of the transverse tensile and fracture toughness test techniques for spent fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, S. B.; Hong, K. P.; Jung, Y. H.; Seo, H. S.; Oh, W. H.; Yoo, B. O.; Kim, D. S.; Seo, K. S

    2001-12-01

    To define the cause of cladding damage which can take place during the operation of nuclear power plant and the storage through the degradation aspect of mechanical characteristics, the transverse tensile an fracture toughness test were developed in hot cell at IMEF(Irradiated Material Experiment Facility). The following hot cell techniques were developed. 1. The development of a jig and a specimen for transverse tensile test 2. The acquisition of a manufacturing technique for the transverse tensile specimen at hot cell 3. The acquisition of testing procedures and an analysis technque for the transverse tensile 4. The dimensional determination of an optimized fracture toughness specimen 5. The acquisition of manufacturing technique for the fracture toughness test specimen at the hot cell 6. The acquisition of testing procedures and analysis technique for the fracture toughness test (Multiple specimen method, DCPD method, Load ratio method)

  19. Study of creep behaviour in P-doped copper with slow strain rate tensile tests

    International Nuclear Information System (INIS)

    Xuexing Yao; Sandstroem, Rolf

    2000-08-01

    Pure copper with addition of phosphorous is planned to be used to construct the canisters for spent nuclear fuel. The copper canisters can be exposed to a creep deformation up to 2-4% at temperatures in services. The ordinary creep strain tests with dead weight loading are generally employed to study the creep behaviour; however, it is reported that an initial plastic deformation of 5-15% takes place when loading the creep specimens at lower temperatures. The slow strain rate tensile test is an alternative to study creep deformation behaviour of materials. Ordinary creep test and slow strain rate tensile test can give the same information in the secondary creep stage. The advantage of the tensile test is that the starting phase is much more controlled than in a creep test. In a tensile test the initial deformation behaviour can be determined and the initial strain of less than 5% can be modelled. In this study slow strain rate tensile tests at strain rate of 10 -4 , 10 -5 , 10 -6 , and 10 -7 /s at 75, 125 and 175 degrees C have been performed on P-doped pure Cu to supplement creep data from conventional creep tests. The deformation behaviour has successfully been modelled. It is shown that the slow strain rate tensile tests can be implemented to study the creep deformation behaviours of pure Cu

  20. Effect of nickel plating upon tensile tests of uranium--0.75 titanium alloy

    International Nuclear Information System (INIS)

    Hemperly, V.C.

    1975-01-01

    Electrolytic-nickel-plated specimens of uranium-0.75 wt percent titanium alloy were tested in air at 20 and 100 percent relative humidities. Tensile-test ductility values were lowered by a high humidity and also by nickel plating alone. Baking the nickel-plated specimens did not eliminate the ductility degradation. Embrittlement because of nickel plating was also evident in tensile tests at -34 0 C. (U.S.)

  1. Tensile Test of Welding Joint Parts for a Plate-type Fuel Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, K. H.; Kim, J. Y.; Kim, H. J.; Yim, J. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    The tensile tests were performed using an INSTRON 4505 (universal tensile) testing machine. These welding joints are composed of two parts for the soundness of the fuel assembly; one is the side plate with a fixing bar and the other is a side plate with an end fitting. These two joint parts are fabricated by TIG welding method. The tensile tests of the welding joints of a plate-type FA are executed by a tensile test. The fixture configurations for the specimen are very important to obtain the strict test results. The maximum strength has an approximately linear correlation with the unit bonding length of the welding joints. In spite of these results, the maximum strengths of the welding joints are satisfied according to the minimum requirement. These tensile tests of the joint parts for a plate-type fuel assembly (FA) have to be executed to evaluate the structural strength. For the tensile test, the joint parts of a FA used in the test are made of aluminum alloy (Al6061-T6)

  2. Tensile Test of Welding Joint Parts for a Plate-type Fuel Assembly

    International Nuclear Information System (INIS)

    Yoon, K. H.; Kim, J. Y.; Kim, H. J.; Yim, J. S.

    2013-01-01

    The tensile tests were performed using an INSTRON 4505 (universal tensile) testing machine. These welding joints are composed of two parts for the soundness of the fuel assembly; one is the side plate with a fixing bar and the other is a side plate with an end fitting. These two joint parts are fabricated by TIG welding method. The tensile tests of the welding joints of a plate-type FA are executed by a tensile test. The fixture configurations for the specimen are very important to obtain the strict test results. The maximum strength has an approximately linear correlation with the unit bonding length of the welding joints. In spite of these results, the maximum strengths of the welding joints are satisfied according to the minimum requirement. These tensile tests of the joint parts for a plate-type fuel assembly (FA) have to be executed to evaluate the structural strength. For the tensile test, the joint parts of a FA used in the test are made of aluminum alloy (Al6061-T6)

  3. An Analysis Of Tensile Test Results to Assess the Innovation Risk for an Additive Manufacturing Technology

    Directory of Open Access Journals (Sweden)

    Adamczak Stanisław

    2015-03-01

    Full Text Available The aim of this study was to assess the innovation risk for an additive manufacturing process. The analysis was based on the results of static tensile tests obtained for specimens made of photocured resin. The assessment involved analyzing the measurement uncertainty by applying the FMEA method. The structure of the causes and effects of the discrepancies was illustrated using the Ishikawa diagram. The risk priority numbers were calculated. The uncertainty of the tensile test measurement was determined for three printing orientations. The results suggest that the material used to fabricate the tensile specimens shows clear anisotropy of the properties in relation to the printing direction.

  4. Experimental Analysis of Tensile Mechanical Properties of Sprayed FRP

    Directory of Open Access Journals (Sweden)

    Zhao Yang

    2016-01-01

    Full Text Available To study the tensile mechanical properties of sprayed FRP, 13 groups of specimens were tested through uniaxial tensile experiments, being analyzed about stress-strain curve, tensile strength, elastic modulus, breaking elongation, and other mechanical properties. Influencing factors on tensile mechanical properties of sprayed FRP such as fiber type, resin type, fiber volume ratio, fiber length, and composite thickness were studied in the paper too. The results show that both fiber type and resin type have an obvious influence on tensile mechanical properties of sprayed FRP. There will be a specific fiber volume ratio for sprayed FRP to obtain the best tensile mechanical property. The increase of fiber length can lead to better tensile performance, while that of composite thickness results in property degradation. The study can provide reference to popularization and application of sprayed FRP material used in structure reinforcement.

  5. Method for independent strain and temperature measurement in polymeric tensile test specimen using embedded FBG sensors

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; McGugan, Malcolm; Mikkelsen, Lars Pilgaard

    2016-01-01

    to calculate independently the strain and temperature are presented in the article, together with a measurement resolution study. This multi-parameter measurement method was applied to an epoxy tensile specimen, tested in a unidirectional tensile test machine with a temperature controlled cabinet. A full......A novel method to obtain independent strain and temperature measurements using embedded Fibre Bragg Grating (FBG) in polymeric tensile test specimens is presented in this paper. The FBG strain and temperature cross-sensitivity was decoupled using two single mode FBG sensors, which were embedded...... of temperature, from 40 C to -10 C. The consistency of the expected theoretical results with the calibration procedure and the experimental validation shows that this proposed method is applicable to measure accurate strain and temperature in polymers during static or fatigue tensile testing. Two different...

  6. Tensile Mechanical Properties and Failure Modes of a Basalt Fiber/Epoxy Resin Composite Material

    OpenAIRE

    He, Jingjing; Shi, Junping; Cao, Xiaoshan; Hu, Yifeng

    2018-01-01

    Uniaxial tensile tests of basalt fiber/epoxy (BF/EP) composite material with four different fiber orientations were conducted under four different fiber volume fractions, and the variations of BF/EP composite material failure modes and tensile mechanical properties were analyzed. The results show that when the fiber volume fraction is constant, the tensile strength, elastic modulus, and limiting strain of BF/EP composite material all decrease with increasing fiber orientation angle. When the ...

  7. Temperature dependency of tensile properties of GFRP composite for wind turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Yong Hak; Kim, Jong Il; Kim, Dong Jin; Lee, Gun Chang [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2012-09-15

    In this study, the temperature dependency of the tensile properties of a glass fiber reinforced plastic (GFRP) used in wind turbine blades was examined. The tensile strength, elastic modulus, and Poisson's ratio of the tensile specimen manufactured from uniaxial (0 .deg.) and triaxial (0/{+-}45.deg) laminate composite plates were measured at four different testing temperatures-room temperature, -30 .deg. C, -50 .deg. C, and 60 .deg. C. It was found that the tensile strengths and elastic moduli of the uniaxial laminates were greater than those of the triaxial laminates over the testing temperature range. The tensile strength of the two laminates was significantly dependent on the testing temperature, while the dependency of the elastic modulus on the temperature was insignificant. Furthermore, it could be considered that the Poisson's ratio changed slightly with a change in the testing temperature.

  8. Temperature dependency of tensile properties of GFRP composite for wind turbine blades

    International Nuclear Information System (INIS)

    Huh, Yong Hak; Kim, Jong Il; Kim, Dong Jin; Lee, Gun Chang

    2012-01-01

    In this study, the temperature dependency of the tensile properties of a glass fiber reinforced plastic (GFRP) used in wind turbine blades was examined. The tensile strength, elastic modulus, and Poisson's ratio of the tensile specimen manufactured from uniaxial (0 .deg.) and triaxial (0/±45.deg) laminate composite plates were measured at four different testing temperatures-room temperature, -30 .deg. C, -50 .deg. C, and 60 .deg. C. It was found that the tensile strengths and elastic moduli of the uniaxial laminates were greater than those of the triaxial laminates over the testing temperature range. The tensile strength of the two laminates was significantly dependent on the testing temperature, while the dependency of the elastic modulus on the temperature was insignificant. Furthermore, it could be considered that the Poisson's ratio changed slightly with a change in the testing temperature

  9. Tensile testing and damage analysis of woven glass-cloth/epoxy laminates at low temperature

    International Nuclear Information System (INIS)

    Kumagai, S.; Shindo, Y.; Horiguchi, K.

    2002-01-01

    In order to evaluate the tensile properties of SL-ES30 glass-cloth/epoxy laminates for superconducting magnets in fusion energy systems, tensile tests were examined both experimentally and analytically. The tensile tests were conducted in accordance with JIS K 7054 at room temperature and liquid nitrogen temperature (77 K). The general specimen geometry was a rectangular dog-bone shape with constant gage length, but with each specimen size having a different specimen width. The experimental finding provides the data for analytical modeling. The model utilizes two damage variables which are determined from experimental data. A finite element method coupled with damage was adopted for the extensional analysis. The effects of temperature, specimen geometry and gripping method on the tensile properties are examined

  10. Void coalescence and fracture behavior of notched and un-notched tensile tested specimens in fine grain dual phase steel

    Energy Technology Data Exchange (ETDEWEB)

    Saeidi, N., E-mail: navidsae@gmail.com [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Ashrafizadeh, F.; Niroumand, B. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Forouzan, M.R.; Mohseni mofidi, S. [Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Barlat, F. [Materials Mechanics Laboratory (MML), Graduate Institute of Ferrous Technology (GIFT), Pohang University of Science and Technology POSTECH, San 31 Hyoja-dong, Nam-gu, Pohang, Gyeongbuk 790-784 (Korea, Republic of)

    2015-09-17

    Due to growing global concern about the environmental issues, steel developers have been forced by automobile makers to produce more efficient steel grades with high strength to weight ratios along with high crashworthiness performance. In order to find deficiencies of the existing steels and develop superior steel products, detailed understanding of deformation and damage behavior in the existing steels is needed. In the present research, deformation and damage evolution during room temperature uniaxial tensile test of a modern high strength Dual Phase Steel, i.e. DP780, were studied. Detailed scanning electron microscopy (SEM) examination of the microstructures of notched and un-notched tensile fractured specimens revealed that in notched specimen, plastic deformation was concentrated more within the notched region. Therefore, much higher reduction in thickness with a high reduction gradient occurred in this region, In the un-notched specimen, however, plastic deformation was more uniformly distributed in larger parts of the gauge length, and therefore, thickness reduction happened with a lower gradient. Although geometric notch on the specimen did not change the void nucleation and growth mechanisms, the kinetics of these phenomena was influenced. On the other hand, voids linkage mechanism tended to change from void coalescence in the un-notched specimen to void sheeting in the notched specimen. Moreover, three different models developed by Brown & Embury (BM), Thomason and Pardoen were employed to predict the final fracture strain. It was revealed that, BM model showed much more accurate predictions for the studied DP steel in comparison with those of Thomason and Pardoens’ models.

  11. Void coalescence and fracture behavior of notched and un-notched tensile tested specimens in fine grain dual phase steel

    International Nuclear Information System (INIS)

    Saeidi, N.; Ashrafizadeh, F.; Niroumand, B.; Forouzan, M.R.; Mohseni mofidi, S.; Barlat, F.

    2015-01-01

    Due to growing global concern about the environmental issues, steel developers have been forced by automobile makers to produce more efficient steel grades with high strength to weight ratios along with high crashworthiness performance. In order to find deficiencies of the existing steels and develop superior steel products, detailed understanding of deformation and damage behavior in the existing steels is needed. In the present research, deformation and damage evolution during room temperature uniaxial tensile test of a modern high strength Dual Phase Steel, i.e. DP780, were studied. Detailed scanning electron microscopy (SEM) examination of the microstructures of notched and un-notched tensile fractured specimens revealed that in notched specimen, plastic deformation was concentrated more within the notched region. Therefore, much higher reduction in thickness with a high reduction gradient occurred in this region, In the un-notched specimen, however, plastic deformation was more uniformly distributed in larger parts of the gauge length, and therefore, thickness reduction happened with a lower gradient. Although geometric notch on the specimen did not change the void nucleation and growth mechanisms, the kinetics of these phenomena was influenced. On the other hand, voids linkage mechanism tended to change from void coalescence in the un-notched specimen to void sheeting in the notched specimen. Moreover, three different models developed by Brown & Embury (BM), Thomason and Pardoen were employed to predict the final fracture strain. It was revealed that, BM model showed much more accurate predictions for the studied DP steel in comparison with those of Thomason and Pardoens’ models

  12. SOLID BURNT BRICKS’ TENSILE STRENGTH

    Directory of Open Access Journals (Sweden)

    Aneta Maroušková

    2017-11-01

    Full Text Available This paper deals with experimental testing of solid burnt bricks and mortar in pure (axial tension. The obtained working diagrams will be further use for a detailed numerical analysis of whole brick masonry column under concentric compressive load. Failure mechanism of compressed brick masonry column is characterized by the appearance and development of vertical tensile cracks in masonry units (bricks passing in the direction of principal stresses and is accompanied by progressive growth of horizontal deformations. These cracks are caused by contraction and interaction between two materials with different mechanical characteristics (brick and mortar. The aim of this paper is more precisely describe the response of quasi-brittle materials to uniaxial loading in tension (for now only the results from three point bending test are available. For these reasons, bricks and mortar tensile behavior is experimentally tested and the obtained results are discussed.

  13. New strain measurement method at axial tensile test of thin films through direct imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jong-Eun [Department of Automotive Engineering, Seoul National Uinversity of Technolgy, 172 Gongneung-2 Dong, Nowon-Gu, Seoul (Korea, Republic of); Park, Jun-Hyub [Department of Mechatronics Engineering, College of Engineering, Tongmyong University, 535, Yongdang-Dong, Nam-Gu, Busan 608-711 (Korea, Republic of); Kang, Dong-Joong [School of Mechanical Eng., Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of)], E-mail: jhyubpark@korea.com

    2008-09-07

    This paper proposes a new method for measuring strain during a tensile test of the specimen with micrometre size through direct imaging. A specimen was newly designed for adoption of direct imaging which was the main contribution of the proposed system. The structure of the specimen has eight indicators that make it possible to adopt direct imaging and it is fabricated using the same process of microelectromechanical system (MEMS) devices to guarantee the feasibility of the tensile test. We implemented a system for non-contact in situ measurement of strain with the specimen, the image-based displacement measurement system. Extension of the gauge length in the specimen could be found robustly by computing the positions of the eight rectangular-shape indicators on the image. Also, for an easy setup procedure, the region of interest was found automatically through the analysis of the edge projection profile along the horizontal direction. To gain confidence in the reliability of the system, the tensile test for the Al-3%Ti thin film was performed, which is widely used as a material in MEMS devices. Tensile tests were performed and displacements were measured using the proposed method and also the capacitance type displacement sensor for comparison. It is demonstrated that the new strain measurement system can be effectively used in the tensile test of the specimen at microscale with easy setup and better accuracy.

  14. DYNAMIC TENSILE TESTING WITH A LARGE SCALE 33 MJ ROTATING DISK IMPACT MACHINE

    OpenAIRE

    Kussmaul , K.; Zimmermann , C.; Issler , W.

    1985-01-01

    A recently completed testing machine for dynamic tensile tests is described. The machine consists essentially of a pendulum which holds the specimen and a large steel disk with a double striking nose fixed to its circumference. Disk diameter measures 2000 mm, while its mass is 6400 kg. The specimens to be tested are tensile specimens with a diameter of up to 20 mm and 300 mm length or CT 15 specimens at various temperatures. Loading velocity ranges from 1 to 150 m/s. The process of specimen-n...

  15. Mechanical Tensile Testing of Titanium 15-3-3-3 and Kevlar 49 at Cryogenic Temperatures

    Science.gov (United States)

    James, Bryan L.; Martinez, Raul M.; Shirron, Peter; Tuttle, Jim; Galassi, Nicholas M.; Mcguinness, Daniel S.; Puckett, David; Francis, John J.; Flom, Yury

    2011-01-01

    Titanium 15-3-3-3 and Kevlar 49 are highly desired materials for structural components in cryogenic applications due to their low thennal conductivity at low temperatures. Previous tests have indicated that titanium 15-3-3-3 becomes increasingly brittle as the temperature decreases. Furthermore, little is known regarding the mechanical properties of Kevlar 49 at low temperatures, most specifically its Young's modulus. This testing investigates the mechanical properties of both materials at cryogenic temperatures through cryogenic mechanical tensile testing to failure. The elongation, ultimate tensile strength, yield strength, and break strength of both materials are provided and analyzed here.

  16. Effects of reclaimed asphalt pavement on indirect tensile strength test of conditioned foamed asphalt mix

    International Nuclear Information System (INIS)

    Katman, Herda Yati; Norhisham, Shuhairy; Ismail, Norlela; Ibrahim, Mohd Rasdan; Matori, Mohd Yazip

    2013-01-01

    This paper presents the results of Indirect Tensile Strength (ITS) Test for samples prepared with reclaimed asphalt pavement (RAP). Samples were conditioned in water at 25°C for 24 hours prior to testing. Results show that recycled aggregate from reclaimed asphalt pavement performs as well as virgin aggregate.

  17. Direct Tensile Test to Assess Healing in Asphalt

    NARCIS (Netherlands)

    Leegwater, G.A.; Scarpas, Athanasios; Erkens, Sandra

    2016-01-01

    Asphalt concrete has the advantageous ability to heal. During rest
    periods, damage present In the material is restored to a certain extent.
    Healing of the material can be observed in iis regaining of strength
    and stiffness after rest periods. In this paper, a new test method is

  18. Direct tensile test to assess healing in asphalt

    NARCIS (Netherlands)

    Leegwater, G.A.; Scarpas, T.; Erkens, S.

    2016-01-01

    Asphalt concrete has the advantageous ability to heal. During rest periods, damage present in the material is restored to a certain extent. Healing of the material can be observed in its regaining of strength and stiffness after rest periods. In this paper, a new test method is presented. It was

  19. Dynamic tensile test of single PET textile cables

    Directory of Open Access Journals (Sweden)

    Pasco F.

    2012-08-01

    Full Text Available The tyres conception involves for certain applications, the use of textile cables as reinforcement. During its use, the tyre undergoes temperatures variations and dynamic loading rates. The consideration of these conditions during the numeric simulations requires the knowledge of the sensitivity of the mechanical behaviour to loading rate and temperature. In this paper, we developed an experimental methodology for testing textile cable up to high strain rate. The main difficulty of testing cables is the optimization of cable fixing on the machine. For that purpose, we adapted the solution of fixing by progressive binding already used in quasi-static, while taking into account constraints inherent to high strain tests. Firstly, the mass of grips was decreased in order to get force signal less sensitive to grips inertia. The method was developed on a high speed hydraulic machine equipped with a thermal enclosure. The investigated temperatures and strain rates range from room temperature to 373 ∘K (100 ∘C and from 0,01 to 100/s, respectively. In addition, the hydraulic machine was equipped with a high speed video camera. The obtained images were analysed by a tracking technique to measure the average strain in the cable (from 50 to 20000 f/s.

  20. Tensile tests and metallography of brazed AISI 316L specimens after irradiation

    International Nuclear Information System (INIS)

    Groot, P.; Franconi, E.

    1994-01-01

    Stainless steel type 316L tensile specimens were vacuum brazed with three kinds of alloys: BNi-5, BNi-6, and BNi-7. The specimens were irradiated up to 0.7 dpa at 353 K in the High Flux Reactor at JRC Petten, the Netherlands. Tensile tests were performed at a constant displacement rate of 10 -3 s -1 at room temperature in the ECN hot cell facility. BNi-5 brazed specimens showed ductile behaviour. Necking and fractures were localized in the plate material. BNi-6 and BNi-7 brazed specimens failed brittle in the brazed zone. This was preceded by uniform deformation of the plate material. Tensile test results of irradiated specimens showed higher stresses due to radiation hardening and a reduction of the elongation of the plate material compared to the reference. SEM examination of the irradiated BNi-6 and BNi-7 fracture surfaces showed nonmetallic phases. These phases were not found in the reference specimens. ((orig.))

  1. Dynamic strain aging of twinning-induced plasticity (TWIP) steel in tensile testing and deep drawing

    International Nuclear Information System (INIS)

    Kim, J.G.; Hong, S.; Anjabin, N.; Park, B.H.; Kim, S.K.; Chin, K.-G.; Lee, S.; Kim, H.S.

    2015-01-01

    The dynamic strain aging (DSA) of metallic materials due to solute atom diffusion to mobile dislocations induce deformation instability with load fluctuations and deformation localizations, hence reducing their sheet formability. In this paper, DSA behaviors of twinning induced plasticity (TWIP) steel with and without Al during tensile testing and deep drawing are investigated in terms of strain localization and the Portevin-Le Chatelier (PLC) band. A theoretical DSA model with internal variables of dislocation density and twin volume fraction is presented for an estimation of strain localization and strain hardening behavior of TWIP steels. The simulation results of the load history and PLC bands during tensile testing and deep drawing are in good agreement with the experimental values. A serration behavior is observed in high-Mn TWIP steels and its tensile residual stress is higher than that in the Al-added TWIP steels, which results in a deformation crack or delayed fracture of deep drawn specimens

  2. Experimental study on uniaxial ratcheting deformation and failure behavior of 304 stainless steel

    International Nuclear Information System (INIS)

    Yang Xianjie; Gao Qing; Cai Lixun; Liu Yujie

    2004-01-01

    In the paper, the tests of cyclic strain ratcheting and low cycle fatigue for 304 stainless steel under uniaxial cyclic straining were carried out to systematically explore the deformation and failure behavior of the material. The experimental study shows that the cyclic strain ratcheting deformation behavior of the material is different from either the uniaxial monotonic tensile one or the cyclic deformation one under the symmetrical cyclic straining with the same strain amplitude, and the strain ratcheting deformation and failure behaviors depend on both the plastic strain amplitude and the strain increment at the cyclic maximum strain. Some significant results were observed

  3. Novel development of the micro-tensile test at elevated temperature using a test structure with integrated micro-heater

    Science.gov (United States)

    Ang, W. C.; Kropelnicki, P.; Soe, Oak; Ling, J. H. L.; Randles, A. B.; Hum, A. J. W.; Tsai, J. M. L.; Tay, A. A. O.; Leong, K. C.; Tan, C. S.

    2012-08-01

    This paper describes the novel development of a micro-tensile testing method that allows testing at elevated temperatures. Instead of using a furnace, a titanium/platinum thin film micro-heater was fabricated on a conventional dog-bone-shaped test structure to heat up its gauge section locally. An infrared (IR) camera with 5 µm resolution was employed to verify the temperature uniformity across the gauge section of the test structure. With this micro-heater-integrated test structure, micro-tensile tests can be performed at elevated temperatures using any conventional tensile testing system without any major modification to the system. In this study, the tensile test of the single crystal silicon (SCS) thin film with (1 0 0) surface orientation and tensile direction was performed at room temperature and elevated temperatures, up to 300 °C. Experimental results for Young's modulus as a function of temperature are presented. A micro-sized SCS film showed a low dependence of mechanical properties on temperature up to 300 °C.

  4. 4-Point beam tensile test on a soft adhesive

    International Nuclear Information System (INIS)

    Budzik, Michal K.; Jumel, Julien; Shanahan, Martin E.R.

    2013-01-01

    Highlights: ► An adhesive butt joint with a soft bondline of variable thickness has been studied. ► We found that bondline thickness affects the stress state in soft bondlines. ► Fracture energy at crack onset is lowest for the thinnest of bondlines and becomes stable for thicker layers. ► Maximum stress decreases with increasing bondline thickness. ► We found that for optimal joint design, rate effects must be taken into account. - Abstract: An adhesive butt joint with a soft bondline has been studied. A series of experiments was conducted on test pieces constituted of aluminium adherends bonded with a low modulus epoxy adhesive, Scotch Weld™ 2216. The joint was subjected to four point bending, in tension/compression loading, under constant deflection rate, with the bondline being parallel to the applied load. The objective was to examine and evaluate crack nucleation for a range of adhesive layer thicknesses. Three criteria were used to evaluate joint efficiency. Firstly, force/stress at crack onset revealed that thinner bondlines were preferable to produce stronger and stiffer bonded structures. Secondly, fracture energy was derived, which, in the present configuration, is associated with the energy stored within the adhesive layer, rather than the substrates. This is one of originalities of the test proposed. Fracture energy data lead to the conclusion, that more energy is dissipated by the joints with lower effective rigidity, viz. thicker bondlines. Finally, we applied a criterion of non-linear, ‘pragmatic’ work of adhesion – similar to the J-integral approach. In terms of energy consumption, the third criterion yielded (quasi) independence of the adhesive thickness. From the data collected, we conclude that for optimal joint design, rate effects must be carefully taken into account

  5. Tensile behavior and tension stiffening of reinforced concrete

    International Nuclear Information System (INIS)

    Choun, Young Sun; Seo, Jeong Moon

    2001-03-01

    For the ultimate behavior analysis of containment buildings under severe accident conditions, a clear understanding of tensile behaviors of plain and reinforced concrete is necessary. Nonlinear models for tensile behaviors of concrete are also needed. This report describe following items: tensile behaviors of plain concrete, test results of reinforced concrete panels in uniaxial and biaxial tension, tension stiffening. The tensile behaviors of reinforced concrete are significantly influenced by the properties of concrete and reinforcing steel. Thus, for a more reliable evaluation of tensile behavior and ultimate pressure capacity of a reinforced or prestressed concrete containment building, an advanced concrete model which can be considered rebar-concrete interaction effects should be developed. In additions, a crack behavior analysis method and tension stiffening models, which are based on fracture mechanics, should be developed. The model should be based on the various test data from specimens considering material and sectional properties of the containment building

  6. Fatigue assessment by energy approach during tensile tests on AISI 304 steel

    Directory of Open Access Journals (Sweden)

    A. Risitano

    2017-01-01

    Full Text Available Estimation of the fatigue limit for steel ductile materials using non-destructive methods is a topic of great interest to researchers today. In recent years, the method adopted has implemented infrared sensors to detect the surface temperature and correlate it with the fatigue limit. In previous paper, a new energy approach was proposed to investigate the fatigue limit during tensile test. The numerical procedure proposed by Chrysochoos is adopted to clean infrared images and applied to analyse the surface heat sources during tensile test. AISI 304 specimens with rectangular cross-sections are tested. Moreover fatigue tests at increasing loads were carried out on steel by a stepwise succession, applied to the same specimen, for applying the thermographic method. The predictions of the fatigue limit, obtained by the analysis of the energy evolution during the static tests, were compared with the predictions obtained applying the thermographic method during fatigue tests.

  7. Stress Wave Attenuation in Aluminum Alloy and Mild Steel Specimens Under SHPB Tensile Testing

    Science.gov (United States)

    Pothnis, J. R.; Ravikumar, G.; Arya, H.; Yerramalli, Chandra S.; Naik, N. K.

    2018-02-01

    Investigations on the effect of intensity of incident pressure wave applied through the striker bar on the specimen force histories and stress wave attenuation during split Hopkinson pressure bar (SHPB) tensile testing are presented. Details of the tensile SHPB along with Lagrangian x- t diagram of the setup are included. Studies were carried out on aluminum alloy 7075 T651 and IS 2062 mild steel. While testing specimens using the tensile SHPB setup, it was observed that the force calculated from the transmitter bar strain gauge was smaller than the force obtained from the incident bar strain gauge. This mismatch between the forces in the incident bar and the transmitter bar is explained on the basis of stress wave attenuation in the specimens. A methodology to obtain force histories using the strain gauges on the specimen during SHPB tensile testing is also presented. Further, scanning electron microscope images and photomicrographs are given. Correlation between the microstructure and mechanical properties is explained. Further, uncertainty analysis was conducted to ascertain the accuracy of the results.

  8. Validatin of miniaturised tensile testing on DMLS TI6AL4V (ELI specimens

    Directory of Open Access Journals (Sweden)

    Van Zyl, Ian

    2016-11-01

    Full Text Available Direct metal laser sintering (DMLS is a relatively new technology that is developing rapidly. Since DMLS material is created by melting/solidifying tracks and layers from powder, even building geometry can influence the mechanical properties. To certify a material, the testing specimens must be designed and manufactured according to the appropriate standards. Miniaturised tensile DMLS samples could be a good alternative for express quality control, and could reduce the cost of DMLS-specific testing. In this study, as-built and stress-relieved miniaturised tensile DMLS Ti6Al4V (ELI specimens with different surface qualities were investigated. The fracture surfaces and mechanical properties of the mini-tensile specimens were analysed and compared with standard full-sized specimens also manufactured by DMLS. The obtained data showed the applicability of mini-tensile tests for the express analysis of DMLS objects if a correction factor is applied for the calculation of the load-bearing cross-section of the specimen.

  9. Fractal and Morphological Characteristics of Single Marble Particle Crushing in Uniaxial Compression Tests

    Directory of Open Access Journals (Sweden)

    Yidong Wang

    2015-01-01

    Full Text Available Crushing of rock particles is a phenomenon commonly encountered in geotechnical engineering practice. It is however difficult to study the crushing of rock particles using classical theory because the physical structure of the particles is complex and irregular. This paper aims at evaluating fractal and morphological characteristics of single rock particle. A large number of particle crushing tests are conducted on single rock particle. The force-displacement curves and the particle size distributions (PSD of crushed particles are analysed based on particle crushing tests. Particle shape plays an important role in both the micro- and macroscale responses of a granular assembly. The PSD of an assortment of rocks are analysed by fractal methods, and the fractal dimension is obtained. A theoretical formula for particle crushing strength is derived, utilising the fractal model, and a simple method is proposed for predicting the probability of particle survival based on the Weibull statistics. Based on a few physical assumptions, simple equations are derived for determining particle crushing energy. The results of applying these equations are tested against the actual experimental data and prove to be very consistent. Fractal theory is therefore applicable for analysis of particle crushing.

  10. HTR 500: Final report of the project '' uniaxial creep tests at controlled temperature''

    International Nuclear Information System (INIS)

    1992-03-01

    The report presents the results of creep trials with HTR-concrete, which were carried out in the scope of development of prestressed concrete - reactor pressure vessels at the ETH Lausanne Institute for Steel and Prestressed Concrete. With temperature, an increase of creep and shrinkage was observed, a lesser dependence on exhaustion and type of concrete. The point in time of reaching the final value is not dependent on temperature for creep, but is for shrinkage. The modulus of elasticity depends on the temperature pre-treatment, but only insignificantly on the test temperature. figs., tabs

  11. Analysis of Factors Influencing Measurement Accuracy of Al Alloy Tensile Test Results

    Science.gov (United States)

    Podgornik, Bojan; Žužek, Borut; Sedlaček, Marko; Kevorkijan, Varužan; Hostej, Boris

    2016-02-01

    In order to properly use materials in design, a complete understanding of and information on their mechanical properties, such as yield and ultimate tensile strength must be obtained. Furthermore, as the design of automotive parts is constantly pushed toward higher limits, excessive measuring uncertainty can lead to unexpected premature failure of the component, thus requiring reliable determination of material properties with low uncertainty. The aim of the present work was to evaluate the effect of different metrology factors, including the number of tested samples, specimens machining and surface quality, specimens input diameter, type of testing and human error on the tensile test results and measurement uncertainty when performed on 2xxx series Al alloy. Results show that the most significant contribution to measurement uncertainty comes from the number of samples tested, which can even exceed 1 %. Furthermore, moving from experimental laboratory conditions to very intense industrial environment further amplifies measurement uncertainty, where even if using automated systems human error cannot be neglected.

  12. The physical interpretation of the parameters measured during the tensile testing of materials at elevated temperatures

    International Nuclear Information System (INIS)

    Burton, B.

    1984-01-01

    Hot tensile (or compression) testing, where the stress developed in a material is measured under an imposed strain rate, is often used as an alternative to conventional creep testing. The advantages of the hot tensile test are that its duration can be more closely controlled by the experimenter and also that the technique is more convenient, since high precision testing machines are available. The main disadvantage is that the interpretation of results is more complex. The present paper relates the parameters which are measured in hot tensile tests, to physical processes which occur in materials deforming by a variety of mechanisms. For cases where no significant structural changes occur, as in viscous or superplastic flow, analytical expressions are derived which relate the stresses measured in these tests to material constants. When deformation is controlled by recovery processes, account has to be taken of the structural changes which occur concurrently. A wide variety of behaviour may then be exhibited which depends on the initial dislocation density, the presence of second-phase particles and the relative values of the recovery rate parameters and the velocity imposed by the testing machine. Numerical examples are provided for simple recovery models. (author)

  13. Utilization of ISO 6892:2009 testing standard for determining tensile properties of TM380 mild steel

    CSIR Research Space (South Africa)

    Shoke, L

    2013-04-01

    Full Text Available mild steel. To achieve this objective, we reviewed the ISO 6892:2009 tensile testing standard along with reported good practice guidelines. Tensile tests were conducted on a dog-bone shaped TM380 mild steel specimen with strain gauges attached on either...

  14. Dynamic tensile tests with superimposed ultrasonic oscillations for stainless steel type 321 at room temperature

    International Nuclear Information System (INIS)

    Schinke, B.; Malmberg, T.

    1987-01-01

    In recent years various containment codes for Fast Breeder Reactor accidents have been assessed by comparison with explosion tests in water-filled vessels (COVA experiments). Common to the various codes, a systematic underestimation of the circumferential vessel strains was found. In the COVA tests high frequency pressure oscillations in the ultrasonic range were observed and thus it has been conjectured that the phenomenon of ''acoustic softening'' might be relevant in explaining the discrepancies in the strains. To validate this conjecture a hydro-pneumatic tensile test apparatus was developed which allows dynamic tensile testing at room temperature with and without superimposed ultrasonic oscillations. The dynamic tensile tests on the COVA sheet material (stainless steel AISI 321) without ultrasonic insonation show a linear dependence of the flow stress on the logarithm of the strain rate. The results at low strain rates (10 -3 s -1 ) agree favourably with previous measurements but at high rates (50 s -1 ) at 20% lower flow stress is observed. The dynamic tensile tests with continuous and intermittent insonation show the phenomenon of ''acoustic softening'': The average flow stress is reduced by an amount of about half the oscillating amplitude. At high strain rates the reduction is less. A severe ''acoustic softening'' observed by several authors for various metals at low strain rates was not observed. The experimental results were compared with the theory of the superpositon mechanism assuming a rate-independent elastic-plastic and an elastic-viscoplastic constitutive model. Although the rate-independent model is capable to predict qualitatively some of the observed effects, a better description is obtained with the viscoplastic model. The conclusion is that the ''acoustic softening'' of the COVA material is far too small to explain the discrepancies between measured and computed strains found in the containment code validation studies. (orig.)

  15. The Evaluation of the Effect of Strain Limits on the Physical Properties of Magnetorheological Elastomers Subjected to Uniaxial and Biaxial Cyclic Testing.

    OpenAIRE

    Gorman, Dave; Murphy, Niall; Ekins, Ray; Jerrams, Stephen

    2017-01-01

    Magnetorheological Elastomers (MREs) are “smart” materials whose physical properties are altered by the application of magnetic fields. In a previous study by the authors [1], variations in the physical properties of MREs have been evaluated when subjected to a range of magnetic field strengths for both uniaxial and biaxial cyclic tests. By applying the same magnetic field to similar samples, this paper investigates the effect of both the upper strain limit and the strain amplitude on the pro...

  16. Tensile testing study of dynamic interactions between dislocations and precipitate in vanadium alloys

    International Nuclear Information System (INIS)

    Tougou, Kouichi; Nogiwa, Kimihiro; Tachikawa, Kazuhiro; Fukumoto, Ken-ichi

    2013-01-01

    To investigate the hardening of fine Ti(OCN) precipitate, we performed in situ transmission electron microscopy (TEM) observations during tensile testing of dislocations gliding through fine Ti(OCN) precipitates in thermally aged V–4Cr–4Ti alloys. The obstacle strength parameter was estimated from the critical bow-out angle, ϕ, of the dislocation lines from the microstructural change during tensile deformation observed in the TEM images. From image processing analysis of the dislocation motion, the value of the obstacle strength parameter of Ti(OCN) precipitates of 4-nm size was determined to be 0.30. The increase in yield stress calculated from the measured dislocation behavior pinned around precipitates was Δσ in situ = 43 MPa, and the increase in yield stress measured by the micro-Vickers hardness test was Δσ HV = 49.5 MPa. Data from in situ TEM observations during tensile testing and from micro-Vickers hardness tests were in good agreement; thus, the obstacle strength parameter of the Ti(OCN) precipitates of 4-nm size was successfully obtained experimentally. The obstacle strength parameter also was compared with data from a previous study, and there was also quite good agreement. Therefore, the obstacle strength parameter obtained from this study is measurable and is a reliable measure of mechanical property changes following precipitation in V–4Cr–4Ti alloys

  17. Development of in-situ rock shear test under low compressive to tensile normal stress

    International Nuclear Information System (INIS)

    Nozaki, Takashi; Shin, Koichi

    2003-01-01

    The purpose of this study is to develop an in-situ rock shear testing method to evaluate the shear strength under low normal stress condition including tensile stress, which is usually ignored in the assessment of safety factor of the foundations for nuclear power plants against sliding. The results are as follows. (1) A new in-situ rock shear testing method is devised, in which tensile normal stress can be applied on the shear plane of a specimen by directly pulling up a steel box bonded to the specimen. By applying the counter shear load to cancel the moment induced by the main shear load, it can obtain shear strength under low normal stress. (2) Some model tests on Oya tuff and diatomaceous mudstone have been performed using the developed test method. The shear strength changed smoothly from low values at tensile normal stresses to higher values at compressive normal stresses. The failure criterion has been found to be bi-linear on the shear stress vs normal stress plane. (author)

  18. Tensile and impact testing of an HFBR [High Flux Beam Reactor] control rod follower

    International Nuclear Information System (INIS)

    Czajkowski, C.J.; Schuster, M.H.; Roberts, T.C.; Milian, L.W.

    1989-08-01

    The Materials Technology Group of the Department of Nuclear Energy (DNE) at Brookhaven National Laboratory (BNL) undertook a program to machine and test specimens from a control rod follower from the High Flux Beam Reactor (HFBR). Tensile and Charpy impact specimens were machined and tested from non-irradiated aluminum alloys in addition to irradiated 6061-T6 from the HFBR. The tensile test results on irradiated material showed a two-fold increase in tensile strength to a maximum of 100.6 ksi. The impact resistance of the irradiated material showed a six-fold decrease in values (3 in-lb average) compared to similar non-irradiated material. Fracture toughness (K I ) specimens were tested on an unirradiated compositionally and dimensionally similar (to HFBR follower) 6061 T-6 material with K max values of 24.8 ± 1.0 Ksi√in (average) being obtained. The report concludes that the specimens produced during the program yielded reproducible and believable results and that proper quality assurance was provided throughout the program. 9 figs., 6 tabs

  19. Ethylene propylene cable degradation during LOCA research tests: tensile properties at the completion of accelerated aging

    International Nuclear Information System (INIS)

    Bustard, L.D.

    1982-05-01

    Six ethylene-propylene rubber (EPR) insulation materials were aged at elevated temperature and radiation stress exposures common in cable LOCA qualification tests. Material samples were subjected to various simultaneous and sequential aging simulations in preparation for accident environmental exposures. Tensile properties subsequent to the aging exposure sequences are reported. The tensile properties of some, but not all, specimens were sensitive to the order of radiation and elevated temperature stress exposure. Other specimens showed more severe degradation when simultaneously exposed to radiation and elevated temperature as opposed to the sequential exposure to the same stresses. Results illustrate the difficulty in defining a single test procedure for nuclear safety-related qualification of EPR elastomers. A common worst-case sequential aging sequence could not be identified

  20. STUDY OF THE MECHANICAL PROPERTIES OF INCONEL 718 SUPERALLOY AFTER HOT TENSILE TESTS

    Directory of Open Access Journals (Sweden)

    Tarcila Sugahara

    2014-10-01

    Full Text Available This research work investigated some important mechanical properties of Inconel 718 superalloy using hot tensile tests like conventional yield strength to 0.2% strain (σe , ultimate strength (σr , and specific elongation (εu . Samples were strained to failure at temperatures of 600°C, 650°C, 700°C, 750°C, 800°C and 850°C and strain rate of 0.5 mm/min (2 × 10–4 s–1 according to ASTM E-8. The results showed higher values σe of yield strength at 700°C, this anomalous behavior can be attributed to the presence of hardening precipitates as observed in the TTT diagram of superalloy Inconel 718. Examination of the sample’s surfaces tensile fracture showed that with increasing temperature test the actuating mechanism changes from intergranular fracture to coalescence of the microcavities.

  1. Deformation and fracture in micro-tensile tests of freestanding electrodeposited nickel thin films

    International Nuclear Information System (INIS)

    Yang, Y.; Yao, N.; Soboyejo, W.O.; Tarquinio, C.

    2008-01-01

    In situ scanning electron microscopy micro-tensile tests were conducted on freestanding LIGA nickel thin films of two thicknesses (70 and 270 μm). The deformation and fracture mechanisms were elucidated by in situ scanning electron microscopy imaging and ex situ fractographic analysis. Due to the film microstructural gradient, an apparent thickness effect on the film yield strengths was observed, which was then rationalized with a continuum micromechanics model

  2. Development of Tensile Softening Model for Plain Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.K.; Song, Y.C. [Korea Electric Power Research Institute, Taejon (Korea)

    2002-07-01

    Large-scale direct tensile softenng tests using plate concrete specimens(4000, 5000psi) with notch were performed under uniaxial stress. There were presented the basic physical properties and the complete load-CMOD(Crack Mouth Opening Displacement) curves for them And them the fracture energy was evaluated using the complete load-CMOD curves respectively, and there was presents optimal tensile softening model which is modified by a little revision of an existing one. Therefore, here provided the real verification data through the tests for developing other nonlinear concrete finite element models. (author). 32 refs., 38 figs., 4 tabs.

  3. Effects of reclaimed asphalt pavement on indirect tensile strength test of foamed asphalt mix tested in dry condition

    International Nuclear Information System (INIS)

    Katman, Herda Yati; Norhisham, Shuhairy; Ismail, Norlela; Ibrahim, Mohd Rasdan; Matori, Mohd Yazip

    2013-01-01

    Indirect tensile strength (ITS) test was conducted to analyse strength of the foamed asphalt mixes incorporating reclaimed asphalt pavement. Samples were tested for ITS after cured in the oven at 40°C for 72 hours. This testing condition known as dry condition or unconditioned. Laboratory results show that reclaimed asphalt pavement (RAP) contents insignificantly affect the ITS results. ITS results significantly affected by foamed bitumen contents.

  4. Hydrogen Induced Crack and Phase Transformation in Hydrogen Pressured Tensile Test of 316L Stainless Steel

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Un Bong; Nam, Sung Hoon [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Choe, Byung Hak; Shim, Jong Hun [Gangneung-Wonju National University, Gangneung (Korea, Republic of); Kim, Young Uk [Hanyang University, Ansan (Korea, Republic of); Kim, Young Suk; Kim, Sung Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Hong, Keyyong [Korea Research Institute of Ship and Ocean Engineering, Deajeon (Korea, Republic of)

    2015-02-15

    The aim of this investigation is to prove the mechanism of hydrogen induced crack (HIC) of 316L stainless steels in hydrogen pressured tensile test. Microstructures like twin, planar slip, and abnormal phase transformation around the HIC were analyzed by transmission electron microscopy. Deformation twin accompanied by planar slip could be related to the main cause of HIC in the hydrogen pressured tensile condition, because intragranular HICs were mainly observed along the boundaries of twins and planar slip lines. An abnormal forbidden diffraction was also accompanied by HIC in the hydrogen attacked area. Examination of the HIC mechanism in austenitic stainless steel can be applied to the fitness of use for alloys with the possibility of various susceptible cracks in a hydrogen and stress atmosphere.

  5. The influences of deformation velocity and temperature on localized deformation of zircaloy-4 in tensile tests

    International Nuclear Information System (INIS)

    Boratto, F.J.M.

    1973-01-01

    A new parameter to describe the necking stability in zircaloy-4 during tensile tests is introduced. The parameter is defined as: s = ∂Ln (dσ/dε)/∂Ln ((1/L)dL/dt) for constant temperature, deformation and history. Measures of stress strain rate sensitivity n, reduction of the area at fracture, and deformation profiles of tensile fracture, are done. A complete description of the curve of non-uniform deformation variation with the temperature, is presented. The results are compared with existing data for pure commercially titanium. The influence of strain rate and history on s and n parameters, in the temperature range from 100-700 0 C). (author) [pt

  6. Triaxial- and uniaxial-compression testing methods developed for extraction of pore water from unsaturated tuff, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Mower, T.E.; Higgins, J.D. [Colorado School of Mines, Golden, CO (USA). Dept. of Geology and Geological Engineering; Yang, I.C. [Geological Survey, Denver, CO (USA). Water Resources Div.

    1989-12-31

    To support the study of hydrologic system in the unsaturated zone at Yucca Mountain, Nevada, two extraction methods were examined to obtain representative, uncontaminated pore-water samples from unsaturated tuff. Results indicate that triaxial compression, which uses a standard cell, can remove pore water from nonwelded tuff that has an initial moisture content greater than 11% by weight; uniaxial compression, which uses a specifically fabricated cell, can extract pore water from nonwelded tuff that has an initial moisture content greater than 8% and from welded tuff that has an initial moisture content greater than 6.5%. For the ambient moisture conditions of Yucca Mountain tuffs, uniaxial compression is the most efficient method of pore-water extraction. 12 refs., 7 figs., 2 tabs.

  7. Device Design and Test of Fatigue Behaviour of Expansion Anchor Subjected to Tensile Loads

    Directory of Open Access Journals (Sweden)

    Zhang Jinfeng

    2016-01-01

    Full Text Available In order to study on the fatigue behaviour of expansion anchor (M16, grade 8.8 for overhead contact system in electrification railways, a set of safe, practical loading device is designed and a fatigue test campaign was carried out at structural laboratory of China Academy of Building Research on expansion anchor embedded in concrete block. The mobile frame of the loading device was designed well by finite-element simulation. According to some fatigue performance test of expansion anchor with different size and form, the device have been assessed experimentally its dependability. The results were found that no fatigue damage phenomenon occurred in all specimens after 2×106 cycles tensile fatigue test in this specific series. It shows that in the condition of medium level or slightly lower maximum stress limit and nominal stress range, expansion bolt has good fatigue resistance. The biggest relative displacement and the residual relative displacement after test (Δδ = δ2-δ1 was also strongly lower than the symbol of the fatigue test failure index of this specific series (0.5mm in the high cycle fatigue regime. The ultimate tension failures mode after fatigue tests in all tested samples take place in the concrete anchorage zone. The reduction range of the ultimate tensile strength properties of the anchorage system was not obvious, and the concrete was seen to be the weakest link of the system.

  8. Standard test method for splitting tensile strength for brittle nuclear waste forms

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1989-01-01

    1.1 This test method is used to measure the static splitting tensile strength of cylindrical specimens of brittle nuclear waste forms. It provides splitting tensile-strength data that can be used to compare the strength of waste forms when tests are done on one size of specimen. 1.2 The test method is applicable to glass, ceramic, and concrete waste forms that are sufficiently homogeneous (Note 1) but not to coated-particle, metal-matrix, bituminous, or plastic waste forms, or concretes with large-scale heterogeneities. Cementitious waste forms with heterogeneities >1 to 2 mm and 5 mm can be tested using this procedure provided the specimen size is increased from the reference size of 12.7 mm diameter by 6 mm length, to 51 mm diameter by 100 mm length, as recommended in Test Method C 496 and Practice C 192. Note 1—Generally, the specimen structural or microstructural heterogeneities must be less than about one-tenth the diameter of the specimen. 1.3 This test method can be used as a quality control chec...

  9. HYBRID CONTINUUM-DISCONTINUUM MODELLING OF ROCK FRACUTRE PROCESS IN BRAZILIAN TENSILE STRENGTH TEST

    Directory of Open Access Journals (Sweden)

    Huaming An

    2017-10-01

    Full Text Available A hybrid continuum-discontinuum method is introduced to model the rock failure process in Brazilian tensile strength (BTS test. The key component of the hybrid continuum-discontinuum method, i.e. transition from continuum to discontinuum through fracture and fragmentation, is introduced in detail. A laboratory test is conducted first to capture the rock fracture pattern in the BTS test while the tensile strength is calculated according to the peak value of the loading forces. Then the proposed method is used to model the rock behaviour during BTS test. The stress propagation is modelled and compared with those modelled by finite element method in literatures. In addition, the crack initiation and propagation are captured and compared with the facture patter in laboratory test. Moreover, the force-loading displacement curve is obtained which represents a typical brittle material failure process. Furthermore, the stress distributions along the vertical direction are compared with the theoretical solution. It is concluded that the hybrid continuum-discontinuum method can model the stress propagation process and the entire rock failure process in BTS test. The proposed method is a valuable numerical tool for studying the rock behaviour involving the fracture and fragmentation processes.

  10. Effects of tensile test parameters on the mechanical properties of a bimodal Al–Mg alloy

    International Nuclear Information System (INIS)

    Magee, Andrew; Ladani, Leila; Topping, Troy D.; Lavernia, Enrique J.

    2012-01-01

    The properties of aluminum alloy (AA) 5083 are shown to be significantly improved by grain size reduction through cryomilling and the incorporation of unmilled Al particles into the material, creating a bimodal grain size distribution consisting of coarse grains in a nanocrystalline matrix. To provide insight into the mechanical behavior and ultimately facilitate engineering applications, the present study reports on the effects of coarse grain ratio, anisotropy, strain rate and specimen size on the elastic–plastic behavior of bimodal AA 5083 evaluated in uniaxial tension tests using a full-factorial experiment design. To determine the governing failure mechanisms under different testing conditions, the specimens’ failure surfaces were analyzed using optical and electron microscopy. The results of the tests were found to conform to Joshi’s plasticity model. Significant anisotropy effects were observed, in a drastic reduction in strength and ductility, when tension was applied perpendicular (transverse) to the direction of extrusion. These specimens also exhibited a smooth, flat fracture surface morphology with a significantly different surface texture than specimens tested in the axial direction. It was found that decreasing specimen thickness and strain rate served to increase both the strength and ductility of the material. The failure surface morphology was found to differ between specimens of different thicknesses.

  11. Characterization of a 14Cr ODS steel by means of small punch and uniaxial testing with regard to creep and fatigue at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Bruchhausen, M., E-mail: matthias.bruchhausen@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, 1755 ZG Petten (Netherlands); Turba, K. [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, 1755 ZG Petten (Netherlands); Lund University, Division of Materials Engineering, P.O. Box 118, SE-221 00 Lund (Sweden); Haan, F. de; Hähner, P.; Austin, T. [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, 1755 ZG Petten (Netherlands); Carlan, Y. de [CEA, DEN, Service de Recherches Métallurgiques Appliquées, 91191 Gif-sur-Yvette (France)

    2014-01-15

    A 14Cr ODS steel was characterized at elevated temperatures with regard to its behavior in small punch and uniaxial creep tests and in low cycle fatigue tests. A comparison of small punch and uniaxial creep tests at 650 °C revealed a strong anisotropy of the material when strained parallel and perpendicular to the extrusion direction with rupture times being several orders of magnitude lower for the perpendicular direction. The stress-rupture and Larson–Miller plots show a very large scatter of the creep data. This scatter is strongly reduced when rupture time is plotted against minimum deflection rate or minimum creep rate (Monkman–Grant plot). Fatigue tests have been carried out at 650 °C and 750 °C. The alloy is cyclically very stable with practically no hardening/softening. Results from the tests at both temperatures can be described by a common power law. An increase in the test temperature has little influence on the fatigue ductility exponent. For a given total strain level, the fatigue life of the alloy is reduced with increasing temperature.

  12. Localized strain measurements of the intervertebral disc annulus during biaxial tensile testing.

    Science.gov (United States)

    Karakolis, Thomas; Callaghan, Jack P

    2015-01-01

    Both inter-lamellar and intra-lamellar failures of the annulus have been described as potential modes of disc herniation. Attempts to characterize initial lamellar failure of the annulus have involved tensile testing of small tissue samples. The purpose of this study was to evaluate a method of measuring local surface strains through image analysis of a tensile test conducted on an isolated sample of annular tissue in order to enhance future studies of intervertebral disc failure. An annulus tissue sample was biaxial strained to 10%. High-resolution images captured the tissue surface throughout testing. Three test conditions were evaluated: submerged, non-submerged and marker. Surface strains were calculated for the two non-marker conditions based on motion of virtual tracking points. Tracking algorithm parameters (grid resolution and template size) were varied to determine the effect on estimated strains. Accuracy of point tracking was assessed through a comparison of the non-marker conditions to a condition involving markers placed on tissue surface. Grid resolution had a larger effect on local strain than template size. Average local strain error ranged from 3% to 9.25% and 0.1% to 2.0%, for the non-submerged and submerged conditions, respectively. Local strain estimation has a relatively high potential for error. Submerging the tissue provided superior strain estimates.

  13. Stress transfer in microdroplet tensile test: PVC-coated and uncoated Kevlar-29 single fiber

    Science.gov (United States)

    Zhenkun, Lei; Quan, Wang; Yilan, Kang; Wei, Qiu; Xuemin, Pan

    2010-11-01

    The single fiber/microdroplet tensile test is applied for evaluating the interfacial mechanics between a fiber and a resin substrate. It is used to investigate the influence of a polymer coating on a Kevlar-29 fiber surface, specifically the stress transfer between the fiber and epoxy resin in a microdroplet. Unlike usual tests, this new test ensures a symmetrical axial stress on the embedded fiber and reduces the stress singularity that appears at the embedded fiber entry. Using a homemade loading device, symmetrical tensile tests are performed on a Kevlar-29 fiber with or without polyvinylchloride (PVC) coating, the surface of which is in contact with two epoxy resin microdroplets during curing. Raman spectra on the embedded fiber are recorded by micro-Raman Spectroscopy under different strain levels. Then they are transformed to the distributions of fiber axis stress based on the relationship between stress and Raman shift. The Raman results reveal that the fiber axial stresses increase with the applied loads, and the antisymmetric interfacial shear stresses, obtained by a straightforward balance of shear-to-axial forces argument, lead to the appearance of shear stress concentrations at a distance to the embedded fiber entry. The load is transferred from the outer fiber to the embedded fiber in the epoxy microdroplet. As is observed by scanning electronic microscopy (SEM), the existence of a flexible polymer coating on the fiber surface reduces the stress transfer efficiency.

  14. In-situ tensile testing of notched poly- and oligocrystalline 316L wires

    Energy Technology Data Exchange (ETDEWEB)

    Mitevski, Bojan [Materials Science and Engineering (ITM), Duisburg (Germany); Weiss, Sabine [Brandenburg Technical Univ., Cottbus-Senftenberg (Germany). Chair of Physical Metallurgy and Materials Science.; Fischer, Alfons [Duisburg-Essen Univ. (Germany). Materials Science and Engineering; Rush Univ. Medical Center, Chicago, IL (United States). Dept. of Orthopedics

    2017-03-01

    In-situ testing inside a scanning electron microscope is a helpful tool for detailed analyses of small sized specimens with respect to their mechanical properties and the correlated microstructural alterations. Thus, this test method is used to analyze the tensional properties of thin 316L (1.4441) wires used for microscale components, e.g., like coronary artery stents. Tensile tests were conducted on unnotched and circularly notched 316L wires (oe 0.95 mm) with a special focus on the number of grains within the cross section as well as the notch geometry. Four combinations of notch width (2 and 4 mm) and notch depth (diameter at notch root: 0.5 and 0.75 mm) were chosen. Notch depth and notch shape were adjusted by means of electrochemical polishing. Previous investigations showed, that oligocrystalline structures exhibit a different mechanical behavior compared to polycrystalline ones or single crystals. There are only a few data available on mechanical testing of oligocrystalline structures with respect to varying notch geometries. Depending on the notch geometry, grain size and, therefore, the number of grains within the notch cross section widely scattering yield- and tensile strength as well as failure elongation values were measured. However, the transition criterion between poly- and oligocrystalline behavior could be quantified to be 6 to 7 grains within the cross section.

  15. Orthodontic brackets removal under shear and tensile bond strength resistance tests - a comparative test between light sources

    Science.gov (United States)

    Silva, P. C. G.; Porto-Neto, S. T.; Lizarelli, R. F. Z.; Bagnato, V. S.

    2008-03-01

    We have investigated if a new LEDs system has enough efficient energy to promote efficient shear and tensile bonding strength resistance under standardized tests. LEDs 470 ± 10 nm can be used to photocure composite during bracket fixation. Advantages considering resistance to tensile and shear bonding strength when these systems were used are necessary to justify their clinical use. Forty eight human extracted premolars teeth and two light sources were selected, one halogen lamp and a LEDs system. Brackets for premolar were bonded through composite resin. Samples were submitted to standardized tests. A comparison between used sources under shear bonding strength test, obtained similar results; however, tensile bonding test showed distinct results: a statistical difference at a level of 1% between exposure times (40 and 60 seconds) and even to an interaction between light source and exposure time. The best result was obtained with halogen lamp use by 60 seconds, even during re-bonding; however LEDs system can be used for bonding and re-bonding brackets if power density could be increased.

  16. Orthodontic brackets removal under shear and tensile bond strength resistance tests – a comparative test between light sources

    International Nuclear Information System (INIS)

    Silva, P C G; Porto-Neto, S T; Lizarelli, R F Z; Bagnato, V S

    2008-01-01

    We have investigated if a new LEDs system has enough efficient energy to promote efficient shear and tensile bonding strength resistance under standardized tests. LEDs 470 ± 10 nm can be used to photocure composite during bracket fixation. Advantages considering resistance to tensile and shear bonding strength when these systems were used are necessary to justify their clinical use. Forty eight human extracted premolars teeth and two light sources were selected, one halogen lamp and a LEDs system. Brackets for premolar were bonded through composite resin. Samples were submitted to standardized tests. A comparison between used sources under shear bonding strength test, obtained similar results; however, tensile bonding test showed distinct results: a statistical difference at a level of 1% between exposure times (40 and 60 seconds) and even to an interaction between light source and exposure time. The best result was obtained with halogen lamp use by 60 seconds, even during re-bonding; however LEDs system can be used for bonding and re-bonding brackets if power density could be increased

  17. Quantitative in situ TEM tensile testing of an individual nickel nanowire

    International Nuclear Information System (INIS)

    Lu Yang; Peng Cheng; Ganesan, Yogeeswaran; Lou Jun; Huang Jianyu

    2011-01-01

    In this paper, we have demonstrated the usage of a novel micro-mechanical device (MMD) to perform quantitative in situ tensile tests on individual metallic nanowires inside a transmission electron microscope (TEM). Our preliminary experiment on a 360 nm diameter nickel nanowire showed that the sample fractured at an engineering stress of ∼ 1.2 GPa and an engineering strain of ∼ 4%, which is consistent with earlier experiments performed inside a scanning electron microscope (SEM). With in situ high resolution TEM imaging and diffraction capabilities, this novel experimental set-up could provide unique opportunities to reveal the underlying deformation and damage mechanisms for metals at the nanoscale.

  18. Development of micro tensile testing method in an FIB system for evaluating grain boundary strength

    International Nuclear Information System (INIS)

    Fujii, Katsuhiko; Fukuya, Koji

    2010-01-01

    A micro tensile testing method for evaluating grain boundary strength was developed. Specimens of 2 x 2 x 10μm having one grain boundary were made by focused ion beam (FIB) micro-processing and tensioned in an FIB system in situ. The load was measured from the deflection of the silicon cantilever. The method was applied to aged and unaged Fe-Mn-P alloy specimens with different level of grain boundary phosphorus segregation. The load at intergranular fracture decreased with increasing phosphorus segregation. (author)

  19. Uniaxial and biaxial tensioning effects on thin membrane materials. [large space structures

    Science.gov (United States)

    Hinson, W. F.; Goslee, J. W.

    1980-01-01

    Thin laminated membranes are being considered for various surface applications on future large space structural systems. Some of the thin membranes would be stretched across or between structural members with the requirement that the membrane be maintained within specified limits of smoothness which would be dictated by the particular applications such as antenna reflector requirements. The multiaxial tensile force required to maintain the smoothness in the membrane needs to be determined for use in the structure design. Therefore, several types of thicknesses of thin membrane materials have been subjected to varied levels of uniaxial and biaxial tensile loads. During the biaxial tests, deviations of the material surface smoothness were measured by a noncontacting capacitance probe. Basic materials consisted of composites of vacuum deposited aluminum on Mylar and Kapton ranging in thickness from 0.00025 in (0.000635 cm) to 0.002 in (0.00508 cm). Some of the material was reinforced with Kevlar and Nomex scrim. The uniaxial tests determined the material elongation and tensile forces up to ultimate conditions. Biaxial tests indicated that a relatively smooth material surface could be achieved with tensile force of approximately 1 to 15 Newtons per centimeter, depending upon the material thickness and/or reinforcement.

  20. A new tensile impact test for the toughness characterization of sheet material

    Science.gov (United States)

    Könemann, Markus; Lenz, David; Brinnel, Victoria; Münstermann, Sebastian

    2018-05-01

    In the past, the selection of suitable steels has been carried out primarily based on the mechanical properties of different steels. One of these properties is the resistance against crack propagation. For many constructions, this value plays an important role, because it can compare the impact toughness of different steel grades easily and gives information about the loading capacity of the specific materials. For thin sheets, impact toughness properties were usually not considered. One of the reasons for this is that the Charpy-impact test is not applicable for sheets with thicknesses below 2 mm. For a long time, this was not relevant because conventional steels had a sufficient impact toughness in a wide temperature range. However, since new multiphase steel grades with improved mechanical property exploitations are available, it turned out that impact toughness properties need to be considered during the component design phase, as the activation of the cleavage fracture mechanism is observed under challenging loading conditions. Therefore, this work aims to provide a new and practical testing procedure for sheet material or thin walled structures. The new testing procedure is based on tensile tests conducted in an impact pendulum similar to the Charpy impact hammer. A new standard geometry is provided, which enables a comparison between different steels or steel grades. A connection to the conventional Charpy test is presented using a damage mechanics model, which predicts material failure with consideration of to the stress state at various temperatures. Different specimen geometries are analysed to cover manifold stress states. A special advantage of the damage mechanics model is also the possibility to predict the materials behaviour in the transition area. To verify the method a conventional steel was tested in Charpy tests as well as in the new tensile impact test.

  1. In-situ tensile test of high strength nanocrystalline bainitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Mike, E-mail: mike.haddad@uni-ulm.de [Institute of Micro and Nanomaterials, University of Ulm, Ulm (Germany); Ivanisenko, Yulia; Courtois-Manara, Eglantine [Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe (Germany); Fecht, Hans-Jörg [Institute of Micro and Nanomaterials, University of Ulm, Ulm (Germany)

    2015-01-03

    Because of its great importance in modern engineering and technology applications, steel continues to be highly relevant in the modern research field of nanocrystalline materials. Innovative processing methods and procedures are required for the production of such materials, which possess superior properties compared to their conventional counter parts. In this research, the original microstructure of a commercial C45 steel (Fe, 0.42–0.5 wt% C, 0.5–0.8 wt% Mn) was modified from ferritic–pearlitic to bainitic. Warm high pressure torsion for 5 rotations at 6 GPa and 350 °C was used to process the bainitic sample leading to an ultrafine/nano-scale grain size. A unique nano-crystalline microstructure consisting of equiaxed and elongated ferrite grains with a mean size smaller than 150 nm appeared in images taken by Transmission Electron Microscopy. Results of in-situ tensile testing in a scanning electron microscope showed very high tensile strength, on the order of 2100 MPa with a total elongation of 4.5% in comparison with 800 MPa and around 16% in the original state. Fracture occurred abruptly, without any sign of necking, and was typically caused by the stress concentration at a surface flaw. Also, stress concentrations near all surface defects were observed on the sample, visualized by the formation of shear bands. The fracture surface was covered with dimples, indicating ductile fracture. These properties are fully comparable with high strength, high alloyed steels.

  2. The tensile strength test of thermoplastic materials based on poly(butylene terephtalate

    Directory of Open Access Journals (Sweden)

    Rzepecka Anna

    2017-01-01

    Full Text Available Thermoplastic composites go toward making an increasingly greater percentage of all manufacturing polymer composites. They have a lot of beneficial properties and their manufacturing using injecting and extrusion methods is a very easy and cheap process. Their properties significantly overtake the properties of traditional materials and it is the reason for their use. Scientists are continuously carrying out research to find new applications of composites materials in new industries, not only in the automotive or aircraft industry. When thermoplastic composites are manufactured a very important factor is the appropriate accommodation of tensile strength to their predestination. Scientists need to know the behaviour of these materials during the impact of different forces, and the factors of working in normal conditions too. The main aim of this article was macroscopic and microscopic analysis of the structure of thermoplastic composites after static tensile strength test. Materials which were analysed were thermoplastic materials which have poly(butylene terephthalate – PBT matrix reinforced with different content glass fibres – from 10% for 30%. In addition, research showed the necessary force to receive fracture and set their distinguishing characteristic down.

  3. Validating Material Modelling of OFHC Copper Using Dynamic Tensile Extrusion (DTE) Test at Different Impact Velocity

    Science.gov (United States)

    Bonora, Nicola; Testa, Gabriel; Ruggiero, Andrew; Iannitti, Gianluca; Hörnqvist, Magnus; Mortazavi, Nooshin

    2015-06-01

    In the Dynamic Tensile Extrusion (DTE) test, the material is subjected to very large strain, high strain rate and elevated temperature. Numerical simulation, validated comparing with measurements obtained on soft-recovered extruded fragments, can be used to probe material response under such extreme conditions and to assess constitutive models. In this work, the results of a parametric investigation on the simulation of DTE test of annealed OFHC copper - at impact velocity ranging from 350 up to 420 m/s - using phenomenological and physically based models (Johnson-Cook, Zerilli-Armstrong and Rusinek-Klepaczko), are presented. Preliminary simulation of microstructure evolution was performed using crystal plasticity package CPFEM, providing, as input, the strain history obtained with FEM at selected locations along the extruded fragments. Results were compared with EBSD investigation.

  4. Strength Restoration of Cracked Sandstone and Coal under a Uniaxial Compression Test and Correlated Damage Source Location Based on Acoustic Emissions

    Science.gov (United States)

    Feng, Xiaowei; Zhang, Nong; Zheng, Xigui; Pan, Dongjiang

    2015-01-01

    Underground rock masses have shown a general trend of natural balance over billions of years of ground movement. Nonetheless, man-made underground constructions disturb this balance and cause rock stability failure. Fractured rock masses are frequently encountered in underground constructions, and this study aims to restore the strength of rock masses that have experienced considerable fracturing under uniaxial compression. Coal and sandstone from a deep-buried coal mine were chosen as experimental subjects; they were crushed by uniaxial compression and then carefully restored by a chemical adhesive called MEYCO 364 with an innovative self-made device. Finally, the restored specimens were crushed once again by uniaxial compression. Axial stress, axial strain, circumferential strain, and volumetric strain data for the entire process were fully captured and are discussed here. An acoustic emission (AE) testing system was adopted to cooperate with the uniaxial compression system to provide better definitions for crack closure thresholds, crack initiation thresholds, crack damage thresholds, and three-dimensional damage source locations in intact and restored specimens. Several remarkable findings were obtained. The restoration effects of coal are considerably better than those of sandstone because the strength recovery coefficient of the former is 1.20, whereas that of the latter is 0.33, which indicates that MEYCO 364 is particularly valid for fractured rocks whose initial intact peak stress is less than that of MEYCO 364. Secondary cracked traces of restored sandstone almost follow the cracked traces of the initial intact sandstone, and the final failure is mainly caused by decoupling between the adhesive and the rock mass. However, cracked traces of restored coal only partially follow the traces of intact coal, with the final failure of the restored coal being caused by both bonding interface decoupling and self-breakage in coal. Three-dimensional damage source

  5. Strength Restoration of Cracked Sandstone and Coal under a Uniaxial Compression Test and Correlated Damage Source Location Based on Acoustic Emissions.

    Directory of Open Access Journals (Sweden)

    Xiaowei Feng

    Full Text Available Underground rock masses have shown a general trend of natural balance over billions of years of ground movement. Nonetheless, man-made underground constructions disturb this balance and cause rock stability failure. Fractured rock masses are frequently encountered in underground constructions, and this study aims to restore the strength of rock masses that have experienced considerable fracturing under uniaxial compression. Coal and sandstone from a deep-buried coal mine were chosen as experimental subjects; they were crushed by uniaxial compression and then carefully restored by a chemical adhesive called MEYCO 364 with an innovative self-made device. Finally, the restored specimens were crushed once again by uniaxial compression. Axial stress, axial strain, circumferential strain, and volumetric strain data for the entire process were fully captured and are discussed here. An acoustic emission (AE testing system was adopted to cooperate with the uniaxial compression system to provide better definitions for crack closure thresholds, crack initiation thresholds, crack damage thresholds, and three-dimensional damage source locations in intact and restored specimens. Several remarkable findings were obtained. The restoration effects of coal are considerably better than those of sandstone because the strength recovery coefficient of the former is 1.20, whereas that of the latter is 0.33, which indicates that MEYCO 364 is particularly valid for fractured rocks whose initial intact peak stress is less than that of MEYCO 364. Secondary cracked traces of restored sandstone almost follow the cracked traces of the initial intact sandstone, and the final failure is mainly caused by decoupling between the adhesive and the rock mass. However, cracked traces of restored coal only partially follow the traces of intact coal, with the final failure of the restored coal being caused by both bonding interface decoupling and self-breakage in coal. Three

  6. Tensile and burst tests in support of the cadmium safety rod failure evaluation

    International Nuclear Information System (INIS)

    Thomas, J.K.

    1992-02-01

    The reactor safety rods may be subjected to high temperatures due to gamma heating after the core coolant level has dropped during the ECS phase of hypothetical LOCA event. Accordingly, an experimental safety rod testing subtask was established as part of a task to address the response of reactor core components to this accident. This report discusses confirmatory separate effects tests conducted to support the evaluation of failures observed in the safety rod thermal tests. As part of the failure evaluation, the potential for liquid metal embrittlement (LME) of the safety rod cladding by cadmium (Cd) -- aluminum (Al) solutions was examined. Based on the test conditions, literature data, and U-Bend tests, its was concluded that the SS304 safety rod cladding would not be subject to LME by liquid Cd-Al solutions under conditions relevant to the safety rod thermal tests or gamma heating accident. To confirm this conclusion, tensile tests on SS304 specimens were performed in both air and liquid Cd-Al solutions with the range of strain rates, temperatures, and loading conditions spanning the range relevant to the safety rod thermal tests and gamma heating accident

  7. Fracture toughness versus micro-tensile bond strength testing of adhesive-dentin interfaces.

    Science.gov (United States)

    De Munck, Jan; Luehrs, Anne-Katrin; Poitevin, André; Van Ende, Annelies; Van Meerbeek, Bart

    2013-06-01

    To assess interfacial fracture toughness of different adhesive approaches and compare to a standard micro-tensile bond-strength (μTBS) test. Chevron-notched beam fracture toughness (CNB) was measured following a modified ISO 24370 standard. Composite bars with dimensions of 3.0×4.0×25 mm were prepared, with the adhesive-dentin interface in the middle. At the adhesive-dentin interface, a chevron notch was prepared using a 0.15 mm thin diamond blade mounted in a water-cooled diamond saw. Each specimen was loaded until failure in a 4-point bend test setup and the fracture toughness was calculated according to the ISO specifications. Similarly, adhesive-dentin micro-specimens (1.0×1.0×8-10 mm) were stressed in tensile until failure to determine the μTBS. A positive correlation (r(2)=0.64) was observed between CNB and μTBS, which however was only nearly statistically significant, mainly due to the dissimilar outcome of Scotchbond Universal (3M ESPE). While few μTBS specimens failed at the adhesive-dentin interface, almost all CNB specimens failed interfacially at the notch tip. Weibull moduli for interfacial fracture toughness were much higher than for μTBS (3.8-11.5 versus 2.7-4.8, respectively), especially relevant with regard to early failures. Although the ranking of the adhesives on their bonding effectiveness tested using CNB and μTBS corresponded well, the outcome of CNB appeared more reliable and less variable. Fracture toughness measurement is however more laborious and requires specific equipment. The μTBS nevertheless appeared to remain a valid method to assess bonding effectiveness in a versatile way. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. Experimental Investigation of Tensile Test on Connection of Cold-formed Cut-curved Steel Section

    Science.gov (United States)

    Sani, Mohd Syahrul Hisyam Mohd; Muftah, Fadhluhartini; Rahman, Nurul Farraheeda Abdul; Fakri Muda, Mohd

    2017-08-01

    Cold-formed steel (CFS) is widely used as structural and non-structural components such as roof trusses and purlin. A CFS channel section with double intermediate web stiffener and lipped is chosen based on the broader usage in roof truss construction. CFS section is cut to form cold-formed pre-cut-curved steel section and lastly strengthened by several types of method or likely known as connection to establish the cold-formed cut-curved steel (CFCCS) section. CFCCS is proposed to be used as a top chord section in the roof truss system. The CFCCS is to resist the buckling phenomena of the roof truss structure and reduced the compression effect on the top chord. The tensile test connection of CFCCS section, especially at the flange element with eight types of connection by welding, plate with self-drilling screw and combination is investigated. The flange element is the weakest part that must be solved first other than the web element because they are being cut totally, 100% of their length for curving process. The testing is done using a universal testing machine for a tensile load. From the experiment, specimen with full welding has shown as a good result with an ultimate load of 13.37 kN and reported having 35.41% when compared with normal specimen without any of connection methods. Furthermore, the experimental result is distinguished by using Eurocode 3. The failure of a full welding specimen is due to breaking at the welding location. Additionally, all specimens with either full weld or spot weld or combination failed due to breaking on weld connection, but specimen with flange plate and self-drilling screw failed due to tilting and bearing. Finally, the full welding specimen is chosen as a good connection to perform the strengthening method of CFCCS section.

  9. Analysis of Ninety Degree Flexure Tests for Characterization of Composite Transverse Tensile Strength

    Science.gov (United States)

    OBrien, T. Kevin; Krueger, Ronald

    2001-01-01

    Finite element (FE) analysis was performed on 3-point and 4-point bending test configurations of ninety degree oriented glass-epoxy and graphite-epoxy composite beams to identify deviations from beam theory predictions. Both linear and geometric non-linear analyses were performed using the ABAQUS finite element code. The 3-point and 4-point bending specimens were first modeled with two-dimensional elements. Three-dimensional finite element models were then performed for selected 4-point bending configurations to study the stress distribution across the width of the specimens and compare the results to the stresses computed from two-dimensional plane strain and plane stress analyses and the stresses from beam theory. Stresses for all configurations were analyzed at load levels corresponding to the measured transverse tensile strength of the material.

  10. Cyclic testing of thin Ni films on a pre-tensile compliant substrate

    Energy Technology Data Exchange (ETDEWEB)

    Wei, He [Department of Mechanics, Tianjin University, 135 Yaguan Rd, Jinnan, 300350 Tianjin (China); Département Physique et Mécanique d es Matériaux, Institut Pprime, CNRS–Université de Poitiers, Bd Marie et Pierre Curie, Futuroscope, 86962 (France); Renault, Pierre-Olivier, E-mail: pierre.olivier.renault@univ-poitiers.fr [Département Physique et Mécanique d es Matériaux, Institut Pprime, CNRS–Université de Poitiers, Bd Marie et Pierre Curie, Futuroscope, 86962 (France); Bourhis, Eric Le [Département Physique et Mécanique d es Matériaux, Institut Pprime, CNRS–Université de Poitiers, Bd Marie et Pierre Curie, Futuroscope, 86962 (France); Wang, Shibin [Department of Mechanics, Tianjin University, 135 Yaguan Rd, Jinnan, 300350 Tianjin (China); Goudeau, Philippe [Département Physique et Mécanique d es Matériaux, Institut Pprime, CNRS–Université de Poitiers, Bd Marie et Pierre Curie, Futuroscope, 86962 (France)

    2017-05-17

    A novel experimental approach to study the cyclic plastic deformation of thin metallic films is presented. 300 nm thick Ni films are deposited on both sides of a pre-tensile soft substrate which allows to deform the films alternately in tension and compression (approximately from +2.7 GPa down to −2 GPa) relative to the as-deposited residual stress state. Nanocrystalline thin films' intrinsic elastic strains (or stresses) and true strains have been measured step by step during two loading/unloading cycles thanks to the X-ray diffraction (XRD) and digital image correlation (DIC) techniques respectively. From the first cyclic deformation, a significant Bauschinger effect is evidenced in the films, however, little or no cyclic hardening is observed during the two cyclic tests.

  11. Tensile toughness test and high temperature fracture analysis of thermal barrier coatings

    International Nuclear Information System (INIS)

    Qian, G.; Nakamura, T.; Berndt, C.C.; Leigh, S.H.

    1997-01-01

    In this paper, an effective fracture toughness test which uses interface fracture mechanics theory is introduced. This method is ideally suited for determining fracture resistance of multilayered thermal barrier coatings (TBCs) consisting of ceramic and bond layers and, unlike other fracture experiments, requires minimal set-up over a simple tensile adhesion test. Furthermore, while other test methods usually use edge cracked specimens, the present test models a crack embedded within the coatings, which is more consistent with actual TBCs where failure initiates from internal voids or defects. The results of combined computational and experimental analysis show that any defects located within the ceramic coating can significantly weaken a TBC, whereas the debonding resistances of the bond coating and its interfaces are found to be much higher. In a separate analysis, the authors have studied fracture behavior of TBCs subjected to thermal loading in a high temperature environment. The computed fracture parameters reveal that when the embedded crack size is on order of the coating thickness, the fracture driving force is comparable to the fracture resistance of the coating found in the toughness test. In addition, the major driving force for fracture derives from the thermal insulating effect across the crack faces rather than the mismatch in the coefficients of thermal expansion. The authors have also investigated the effects of functionally graded material (FGM) within TBCs and found its influences on the fracture parameters to be small. This result implies that the FGM may not contribute toward enhancing the fracture toughness of the TBCs considered here

  12. Effect of curing and silanizing on composite repair bond strength using an improved micro-tensile test method.

    Science.gov (United States)

    Eliasson, Sigfus Thor; Dahl, Jon E

    2017-01-01

    Objectives: To evaluate the micro-tensile repair bond strength between aged and new composite, using silane and adhesives that were cured or left uncured when new composite was placed. Methods: Eighty Filtek Supreme XLT composite blocks and four control blocks were stored in water for two weeks and thermo-cycled. Sandpaper ground, etched and rinsed specimens were divided into two experimental groups: A, no further treatment and B, the surface was coated with bis-silane. Each group was divided into subgroups: (1) Adper Scotchbond Multi-Purpose, (2) Adper Scotchbond Multi-Purpose adhesive, (3) Adper Scotchbond Universal, (4) Clearfil SE Bond and (5) One Step Plus. For each adhesive group, the adhesive was (a) cured according to manufacturer's instructions or (b) not cured before repair. The substrate blocks were repaired with Filtek Supreme XLT. After aging, they were serially sectioned, producing 1.1 × 1.1 mm square test rods. The rods were prepared for tensile testing and tensile strength calculated at fracture. Type of fracture was examined under microscope. Results: Leaving the adhesive uncured prior to composite repair placement increased the mean tensile values statistically significant for all adhesives tested, with or without silane pretreatment. Silane surface treatment improved significantly ( p strength values for all adhesives, both for the cured and uncured groups. The mean strength of the control composite was higher than the strongest repair strength ( p strength. Not curing the adhesive before composite placement increased the tensile bond strength.

  13. Effect of test temperature on tensile and fatigue properties of nickel-base heat-resistant alloys

    International Nuclear Information System (INIS)

    Tsuji, Hirokazu; Nakajima, Hajime

    1987-01-01

    A series of tensile and strain controlled low-cycle fatigue tests were conducted at temperatures ranging from RT to 900 0 C on a nickel-base heat-resistant alloy, Hastelloy XR-II, which is one of the candidate alloys for applications in the process heating high-temperature gas-cooled reactor (HTGR). Fatigue tests at room temperature and all tensile tests were conducted in air, while fatigue tests at and above 400 0 C were conducted in the simulated HTGR helium environment. In those tests the effect of test temperature on tensile and fatigue properties was investigated. The ductility minimum point was observed near 600 0 C, while tensile and fatigue strengths decreased with increasing test temperature. The fatigue lives estimated with the method proposed by Manson were compatible with the experimental results under the given conditions. For the specimens fatigued at and above 700 0 C, the percentage of the intergranular fracture mode gradually increased with increasing test temperature. (orig.)

  14. Characterization of the deformation texture after tensile test and cold rolling of a Ti-6Al-4V sheet alloy

    International Nuclear Information System (INIS)

    Mehdi, B; Badji, R; Azzeddine, H; Alili, B; Bradai, D; Ji, V

    2015-01-01

    The deformation texture after cold rolling and tensile test of an industrial Ti-6Al-4V sheet alloy was studied using X-ray diffraction. The alloy was subjected to a cold rolling to different thickness reductions (from 20% to 60%) and then tensile tests have been carried out along three directions relatively to the rolling direction (0°, 45° and 90°). The experimental results were compared to the existing literature and discussed in terms of active plastic deformation mechanisms. (paper)

  15. Plain-Woven, 600-Denier Kevlar KM2 Fabric Under Quasistatic, Uniaxial Tension

    Science.gov (United States)

    2005-03-01

    respectively, along the direction of applied tensile loading, and Sfail and Efail denote the values corresponding to material failure. 2.2 Least...uniaxial tension along the fill direction. 7 Table 1. Failure strain and failure stress (strength) from each test. Test Efail Sfail (GPa) W1 0.122633...14539.8 7214.87 d (GPa) –4898.41 –10674.6 –33428.5 –14475.3 e –22.0527 –15.6910 –34.3400 –28.6378 f 465.297 476.711 2137.94 1266.84 Efail 0.132930

  16. Tensile test and interface retention forces between wires and composites in lingual fixed retainers.

    Science.gov (United States)

    Paolone, Maria Giacinta; Kaitsas, Roberto; Obach, Patricia; Kaitsas, Vasilios; Benedicenti, Stefano; Sorrenti, Eugenio; Barberi, Fabrizio

    2015-06-01

    In daily orthodontic clinical practice retention is very important, and lingual retainers are part of this challenge. The failure of lingual retainers may be due to many factors. The aim of this study was to assess the retention forces and mechanical behavior of different types of wires matched with different kinds of composites in lingual retainers. A tensile test was performed on cylindrical composite test specimens bonded to orthodontic wires. The specimens were constructed using four different wires: a straight wire (Remanium .016×.022″ Dentaurum), two round twisted wires (Penta One .0215″ Masel, Gold Penta Twisted .0215″ Gold N'braces) and a rectangular braided wire (D-Rect .016×.022″ Ormco); and three composites: two micro-hybrids (Micro-Hybrid Enamel Plus HFO Micerium, and Micro-Hybrid SDR U Dentsply) and a micro-nano-filled composite (Micro-Nano-Filled Transbond LR 3M). The test was performed at a speed of 10mm/min on an Inström device. The wire was fixed with a clamp. The results showed that the bonding between wires and composites in lingual fixed retainers seemed to be lowest for rectangular smooth wires and increased in round twisted and rectangular twisted wires where the bonding was so strong that the maximum tension/bond strength was greater than the ultimate tensile strength of the wire. The highest values were in rectangular twisted wires. Concerning the composites, hybrid composites had the lowest interface bonding values and broke very quickly, while the nano- and micro-composites tolerated stronger forces and displayed higher bonding values. The best results were observed with the golden twisted wire and reached 21.46 MPa with the Transbond composite. With the rectangular braided wire the retention forces were so high that the Enamel Plus composite fractured when the load exceeded 154.6 N/MPa. When the same wire was combined with the Transbond LR either the wire or the composite broke when the force exceeded 240 N. The results of this

  17. Ab initio elastic properties and tensile strength of crystalline hydroxyapatite.

    Science.gov (United States)

    Ching, W Y; Rulis, Paul; Misra, A

    2009-10-01

    We report elastic constant calculation and a "theoretical" tensile experiment on stoichiometric hydroxyapatite (HAP) crystal using an ab initio technique. These results compare favorably with a variety of measured data. Theoretical tensile experiments are performed on the orthorhombic cell of HAP for both uniaxial and biaxial loading. The results show considerable anisotropy in the stress-strain behavior. It is shown that the failure behavior of the perfect HAP crystal is brittle for tension along the z-axis with a maximum stress of 9.6 GPa at 10% strain. Biaxial failure envelopes from six "theoretical" loading tests show a highly anisotropic pattern. Structural analysis of the crystal under various stages of tensile strain reveals that the deformation behavior manifests itself mainly in the rotation of the PO(4) tetrahedron with concomitant movements of both the columnar and axial Ca ions. These results are discussed in the context of mechanical properties of bioceramic composites relevant to mineralized tissues.

  18. Definition of the linearity loss of the surface temperature in static tensile tests

    Directory of Open Access Journals (Sweden)

    A. Risitano

    2014-10-01

    Full Text Available Static tensile tests on material for mechanical constructions have pointed out the linearity loss of the surface temperature with the application of load. This phenomenon is due to the heat generation caused by the local microplasticizations which carry the material to deviate from its completely thermoelastic behavior,. The identification of the static load which determines the loss of linearity of the temperature under stress, becomes extremely important to define a first dynamic characterization of the material. The temperature variations that can be recorded during the static test are often very limited (a few tenths of degree for every 100 MPa in steels and they require the use of special sensors able to measure very low temperature variations. The experience acquired in such analysis highlighted that, dealing with highly accurate sensors or with particular materials, the identification of the first linearity loss (often by eye in the temperature curves, can be influenced by the sensibility of the investigator himself and can lead to incorrect estimates. The aim of this work is to validate the above mentioned observations on different steels, by applying the autocorrelation function to the data collected during the application of a static load. This, in order to make the results of the thermal analysis free from the sensitivity of the operator and to make the results as objective as possible, for defining the closest time of the linearity loss in the temperature-time function.

  19. Fracture Testing with Surface Crack Specimens. [especially the residual tensile strength test

    Science.gov (United States)

    Orange, T. W.

    1974-01-01

    Recommendations are given for the design, preparation, and static fracture testing of surface crack specimens. The recommendations are preceded by background information including discussions of stress intensity factors, crack opening displacements, and fracture toughness values associated with surface crack specimens. Cyclic load and sustained load tests are discussed briefly.

  20. New method to calculate the mechanical properties of unirradiated fuel cladding from ring tensile tests

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Rengel, M.A. [Departamento de Ciencia de Materiales, UPM, E.T.S.I. Caminos, Canales y Puertos, Profesor Aranguren s/n, E-28040 Madrid (Spain); Consejo de Seguridad Nuclear (CSN), Justo Dorado 11, E-28040 Madrid (Spain); Gomez, F.J.; Ruiz-Hervias, J.; Caballero, L.; Valiente, A. [Departamento de Ciencia de Materiales, UPM, E.T.S.I. Caminos, Canales y Puertos, Profesor Aranguren s/n, E-28040 Madrid (Spain)

    2009-06-15

    Nuclear fuel cladding is the first barrier used to confine the fuel and the fission products produced during irradiation. Zirconium alloys are used for this purpose due to their remarkable neutron transparency, together with their good mechanical properties at operational temperatures. Consequently, it is very important to be able to characterize the mechanical response of the irradiated cladding. The mechanical behaviour of the material can be modelled as elastoplastic with different stress-strain curves depending on the direction: radial, hoop or longitudinal direction. The ring tensile test has been proposed to determine the mechanical properties of the cladding along the hoop direction. The initial test consisted of applying a force inside the tube, by means of two half cylinders. Later Arsene and Bai [1,2] modified the experimental device to avoid tube bending at the beginning of the test. The same authors proposed a numerical method to obtain the stress-strain curve in the hoop direction from the experimental load versus displacement results and a given friction coefficient between the loading pieces and the sample [3]. This method has been used by different authors [4] with slight modifications. It is based on the existence of two universal curves under small strain hypothesis: the first correlating the hoop strain and the displacement of the loading piece and the second one correlating the hoop stress and the applied load. In this work, a new method to determine the mechanical properties of the cladding from the ring tensile test results is proposed. Non-linear geometry is considered and an iterative procedure is proposed so universal curves are not needed. A stress-strain curve is determined by combining numerical calculations with experimental results in a convergent loop. The two universal curves proposed by Arsene and Bai [3] are substituted by two relationships, one between the equivalent plastic strain in the centre of the specimen ligament and the

  1. Investigating the effects of a Ga layer on an Al grain boundary by a first-principles computational tensile test

    International Nuclear Information System (INIS)

    Zhang Ying; Lu Guanghong; Wang Tianmin; Kohyama, Masanori

    2009-01-01

    We have performed a first-principles computational tensile test on an Al grain boundary (GB) with a Ga layer. The tensile strength, the toughness and the Griffith energy for the Ga-layer segregated GB are, respectively, 17%, 19% and 23% lower than those of the clean GB, which indicates that the GB is weakened. A closely-packed Ga cluster is formed following the breaking of some Ga–Ga bonds at a certain tensile strain, leading to the formation of a void-like structure in the GB. It is suggested that the GB weakening is directly associated with the formed void-like structure, which makes the applied stress concentrate mainly on the Ga cluster. The final fracture occurs inside the Ga layer. The weakened GB may contribute to the Ga-induced Al GB embrittlement

  2. Evaluation of interface adhesion of hot-dipped zinc coating on TRIP steel with tensile testing and finite element calculation

    NARCIS (Netherlands)

    Song, G.M.; De Hosson, J.T.M.; Sloof, W.G.; Pei, Y.T.

    In this work, a methodology for the determination of the interface adhesion strength of zinc coating on TRIP steel is present. This method consists of a conventional tensile test in combination with finite element calculation. The relation between the average interface crack length and the applied

  3. Construction of cryogenic testing system and tensile deformation behavior of AISI 300 series stainless steels at cryogenic temperatures

    International Nuclear Information System (INIS)

    Lee, H.M.; Nahm, S.H.; Huh, Y.H.; Lee, J.J.; Bahng, G.W.

    1990-01-01

    For practical application of cryogenic engineering, development and characterization of structural materials for use at low temperatures are essential. For these purposes, a system for mechanical testing at liquid helium temperatures was developed and it was shown that the precision and accuracy of the system met the requirements of standards for materials testing machines. Using this system, tensile deformation behavior of AISI 304,316 and 310S austenitic stainless steels at cryogenic temperatures was investigated. Tests were conducted on round, tensile specimens having a 6.25mm diameter at 4,77, and 295 K and loading rate was 0.5mm/min. Serrations were observed in all alloys at 4 K. The stress-displacement curves at 77 and 4 K showed different tendency from those at 298 K. As the testing temperature decreased, ultimate strengths of 304 and 316 were largely increased compared to the increase of yield strengths, but the increase of ultimate strength of 310S was almost the same to that of yield strength. Type 310S had the highest yield strength and the lowest tensile strength at all temperatutes. These tensile characteristics were considered to be strongly affected by austenite stability.(Author)

  4. In-vitro tensile testing machine for vibration study of fresh rabbit Achilles tendon

    Science.gov (United States)

    Revel, Gian M.; Scalise, Alessandro; Scalise, Lorenzo; Pianosi, Antonella

    2001-10-01

    A lot of people, overall athletic one suffer from tendinitis or complete rupture of the Achilles tendon. This structure becomes inflamed and damaged mainly from a variety of mechanical forces and sometimes due to metabolic problems, such as diabetes or arthritis. Over the past three decades extensive studies have been performed on the structural and mechanical properties of Achilles tendon trying to explain the constitutive equations to describe and foresee tendon behavior. Among the various mechanical parameters, the vibrational behavior is also of interest. Several investigations are performed in order to study how the Achilles tendon vibrations influence the response of the muscle proprioception and human posture. The present article describes how in vitro tensile experiments can be performed, taking into account the need to simulate physiological condition of Achilles tendon and thus approaching some opened problems in the design of the experimental set-up. A new system for evaluating tendon vibrations by non contact techniques is proposed. Preliminary simple elongation tests are made extracting the main mechanical parameters: stress and strain at different fixed stretches, in order to characterize the tissue. Finally, a vibration study is made at each pretensioned tendon level evaluating the oscillating curves caused by a small hammer.

  5. Circumferential tensile test method for mechanical property evaluation of SiC/SiC tube

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ju-Hyeon, E-mail: 15096018@mmm.muroran-it.ac.jp [Graduate School, Muroran Institute of Technology, 27-1, Muroran, Hokkaido (Japan); Kishimoto, Hirotatsu [Graduate School, Muroran Institute of Technology, 27-1, Muroran, Hokkaido (Japan); OASIS, Muroran Institute of Technology, 27-1, Muroran, Hokkaido (Japan); Park, Joon-soo [OASIS, Muroran Institute of Technology, 27-1, Muroran, Hokkaido (Japan); Nakazato, Naofumi [Graduate School, Muroran Institute of Technology, 27-1, Muroran, Hokkaido (Japan); Kohyama, Akira [OASIS, Muroran Institute of Technology, 27-1, Muroran, Hokkaido (Japan)

    2016-11-01

    Highlights: • NITE SiC/SiC cooling channel system to be a candidate of divertor system in future. • Hoop strength is one of the important factors for a tube. • This research studies the relationship between deformation and strain of SiC/SiC tube. - Abstract: SiC fiber reinforced/SiC matrix (SiC/SiC) composite is expected to be a candidate material for the first-wall, components in the blanket and divertor of fusion reactors in future. In such components, SiC/SiC composites need to be formed to be various shapes. SiC/SiC tubes has been expected to be employed for blanket and divertor after DEMO reactor, but there is not established mechanical investigation technique. Recent progress of SiC/SiC processing techniques is likely to realize strong, having gas tightness SiC/SiC tubes which will contribute for the development of fusion reactors. This research studies the relationship between deformation and strain of SiC/SiC tube using a circumferential tensile test method to establish a mechanical property investigation method of SiC/SiC tubes.

  6. Stress-deformed state of cylindrical specimens during indirect tensile strength testing

    Directory of Open Access Journals (Sweden)

    Levan Japaridze

    2015-10-01

    Full Text Available In this study, the interaction between cylindrical specimen made of homogeneous, isotropic, and linearly elastic material and loading jaws of any curvature is considered in the Brazilian test. It is assumed that the specimen is diametrically compressed by elliptic normal contact stresses. The frictional contact stresses between the specimen and platens are neglected. The analytical solution starts from the contact problem of the loading jaws of any curvature and cylindrical specimen. The contact width, corresponding loading angle (2θ0, and elliptical stresses obtained through solution of the contact problems are used as boundary conditions for a cylindrical specimen. The problem of the theory of elasticity for a cylinder is solved using Muskhelishvili's method. In this method, the displacements and stresses are represented in terms of two analytical functions of a complex variable. In the main approaches, the nonlinear interaction between the loading bearing blocks and the specimen as well as the curvature of their surfaces and the elastic parameters of their materials are taken into account. Numerical examples are solved using MATLAB to demonstrate the influence of deformability, curvature of the specimen and platens on the distribution of the normal contact stresses as well as on the tensile and compressive stresses acting across the loaded diameter. Derived equations also allow calculating the modulus of elasticity, total deformation modulus and creep parameters of the specimen material based on the experimental data of radial contraction of the specimen.

  7. High Strain Rate Tensile Testing of Silver Nanowires: Rate-Dependent Brittle-to-Ductile Transition.

    Science.gov (United States)

    Ramachandramoorthy, Rajaprakash; Gao, Wei; Bernal, Rodrigo; Espinosa, Horacio

    2016-01-13

    The characterization of nanomaterials under high strain rates is critical to understand their suitability for dynamic applications such as nanoresonators and nanoswitches. It is also of great theoretical importance to explore nanomechanics with dynamic and rate effects. Here, we report in situ scanning electron microscope (SEM) tensile testing of bicrystalline silver nanowires at strain rates up to 2/s, which is 2 orders of magnitude higher than previously reported in the literature. The experiments are enabled by a microelectromechanical system (MEMS) with fast response time. It was identified that the nanowire plastic deformation has a small activation volume (ductile failure mode transition was observed at a threshold strain rate of 0.2/s. Transmission electron microscopy (TEM) revealed that along the nanowire, dislocation density and spatial distribution of plastic regions increase with increasing strain rate. Furthermore, molecular dynamic (MD) simulations show that deformation mechanisms such as grain boundary migration and dislocation interactions are responsible for such ductility. Finally, the MD and experimental results were interpreted using dislocation nucleation theory. The predicted yield stress values are in agreement with the experimental results for strain rates above 0.2/s when ductility is pronounced. At low strain rates, random imperfections on the nanowire surface trigger localized plasticity, leading to a brittle-like failure.

  8. Evaluation of the tensile strength of the human ureter - Preliminary results.

    Science.gov (United States)

    Shilo, Yaniv; Pichamuthu, Joseph E; Averch, Timothy D; Vorp, David A

    2014-09-15

    Introduction: Ureteral injuries such as avulsion are directly related to mechanical damage of the ureter. Understanding the tensile strength of this tissue may assist in prevention of iatrogenic injuries. Few published studies have looked at the mechanical properties of the animal ureter, and of those none have determined the tensile strength of the human ureter. Therefore, the purpose of this work was to determine the tensile strength of the human ureter. Materials and Methods: We harvested 11 human proximal ureters from patients who were undergoing nephrectomy for either kidney tumors or non-functioning kidney. The specimens were then cut into multiple circumferentially and longitudinally-oriented tissue strips for tensile testing. Strips were uniaxially stretched to failure in a tensile testing machine. The corresponding force and displacement were recorded. Finally, stress at failure was noted as the tensile strength of the sample. Circumferential tensile strength was also compared in the proximal and distal regions of the specimens. Results: The tensile strength of the ureter in circumferential and longitudinal orientations was found to be 457.52±33.74 Ncm-2 and 902.43±122.08 Ncm-2, respectively (ptensile strength of the ureter was found to be significantly lower than the longitudinal strength. Circumferential tensile strength was also lower with more proximal parts of the ureter. This information may be important for the design of "intelligent" devices and simulators in order to prevent complications.

  9. Evaluation of the tensile strength of the human ureter--preliminary results.

    Science.gov (United States)

    Shilo, Yaniv; Pichamuthu, Joseph E; Averch, Timothy D; Vorp, David A

    2014-12-01

    Ureteral injuries such as avulsion are directly related to mechanical damage of the ureter. Understanding the tensile strength of this tissue may assist in prevention of iatrogenic injuries. Few published studies have looked at the mechanical properties of the animal ureter and, of those, none has determined the tensile strength of the human ureter. Therefore, the purpose of this work was to determine the tensile strength of the human ureter. We harvested 11 human proximal ureters from patients who were undergoing nephrectomy for either kidney tumors or nonfunctioning kidney. The specimens were then cut into multiple circumferentially and longitudinally oriented tissue strips for tensile testing. Strips were uniaxially stretched to failure in a tensile testing machine. The corresponding force and displacement were recorded. Finally, stress at failure was noted as the tensile strength of the sample. Circumferential tensile strength was also compared in the proximal and distal regions of the specimens. The tensile strength of the ureter in circumferential and longitudinal orientations was found to be 457.52±33.74 Ncm(-2) and 902.43±122.08 Ncm(-2), respectively (Ptensile strength of the ureter was found to be significantly lower than the longitudinal strength. Circumferential tensile strength was also lower with more proximal parts of the ureter. This information may be important for the design of "intelligent" devices and simulators to prevent complications.

  10. Tensile creep of beta phase zircaloy-2

    International Nuclear Information System (INIS)

    Burton, B.; Reynolds, G.L.; Barnes, J.P.

    1977-08-01

    The tensile creep and creep rupture properties of beta-phase zircaloy-2 are studied under vacuum in the temperature and stress range 1300-1550 K and 0.5-2 MN/m 2 . The new results are compared with previously reported uniaxial and biaxial data. A small but systematic difference is noted between the uniaxial and biaxial creep data and reasons for this discrepancy are discussed. (author)

  11. Mechanical characterisation of porcine rectus sheath under uniaxial and biaxial tension.

    LENUS (Irish Health Repository)

    Lyons, Mathew

    2014-06-03

    Incisional hernia development is a significant complication after laparoscopic abdominal surgery. Intra-abdominal pressure (IAP) is known to initiate the extrusion of intestines through the abdominal wall, but there is limited data on the mechanics of IAP generation and the structural properties of rectus sheath. This paper presents an explanation of the mechanics of IAP development, a study of the uniaxial and biaxial tensile properties of porcine rectus sheath, and a simple computational investigation of the tissue. Analysis using Laplace׳s law showed a circumferential stress in the abdominal wall of approx. 1.1MPa due to an IAP of 11kPa, commonly seen during coughing. Uniaxial and biaxial tensile tests were conducted on samples of porcine rectus sheath to characterise the stress-stretch responses of the tissue. Under uniaxial tension, fibre direction samples failed on average at a stress of 4.5MPa at a stretch of 1.07 while cross-fibre samples failed at a stress of 1.6MPa under a stretch of 1.29. Under equi-biaxial tension, failure occurred at 1.6MPa with the fibre direction stretching to only 1.02 while the cross-fibre direction stretched to 1.13. Uniaxial and biaxial stress-stretch plots are presented allowing detailed modelling of the tissue either in silico or in a surrogate material. An FeBio computational model of the tissue is presented using a combination of an Ogden and an exponential power law model to represent the matrix and fibres respectively. The structural properties of porcine rectus sheath have been characterised and add to the small set of human data in the literature with which it may be possible to develop methods to reduce the incidence of incisional hernia development.

  12. Acquirement of true stress-strain curve using true fracture strain obtained by tensile test and FE analysis

    International Nuclear Information System (INIS)

    Lee, Kyoung Yoon; Kim, Tae Hyung; Lee, Hyung Yil

    2009-01-01

    In this work, we predict a true fracture strain using load-displacement curves from tensile test and Finite Element Analysis (FEA), and suggest a method for acquiring true Stress-Strain (SS) curves by predicted fracture strain. We first derived the true SS curve up to necking point from load-displacement curve. As the beginning, the posterior necking part of true SS curve is linearly extrapolated with the slope at necking point. The whole SS curve is then adopted for FE simulation of tensile test. The Bridgman factor or suitable plate correction factors are applied to pre and post FEA. In the load-true strain curve from FEA, the true fracture strain is determined as the matching point to test fracture load. The determined true strain is validated by comparing with test fracture strain. Finally, we complete the true SS curve by combining the prior necking part and linear part, the latter of which connects necking and predicted fracture points.

  13. Acquirement of true stress-strain curve using true fracture strain obtained by tensile test and FE analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyoung Yoon; Kim, Tae Hyung; Lee, Hyung Yil [Sogang University, Seoul (Korea, Republic of)

    2009-07-01

    In this work, we predict a true fracture strain using load-displacement curves from tensile test and Finite Element Analysis (FEA), and suggest a method for acquiring true Stress-Strain (SS) curves by predicted fracture strain. We first derived the true SS curve up to necking point from load-displacement curve. As the beginning, the posterior necking part of true SS curve is linearly extrapolated with the slope at necking point. The whole SS curve is then adopted for FE simulation of tensile test. The Bridgman factor or suitable plate correction factors are applied to pre and post FEA. In the load-true strain curve from FEA, the true fracture strain is determined as the matching point to test fracture load. The determined true strain is validated by comparing with test fracture strain. Finally, we complete the true SS curve by combining the prior necking part and linear part, the latter of which connects necking and predicted fracture points.

  14. Acquirement of True Stress-strain Curve Using True Fracture Strain Obtained by Tensile Test and FE Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyoung Yoon; Lee, Hyung Yil [Sogang University, Seoul (Korea, Republic of); Kim, Tae Hyung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-10-15

    In this work, we predict a true fracture strain using load-displacement curves from tensile test and finite element analysis (FEA), and suggest a method for acquiring true stress-strain (SS) curves by predicted fracture strain. We first derived the true SS curve up to necking point from load-displacement curve. As the beginning, the posterior necking part of true SS curve is linearly extrapolated with the slope at necking point. The whole SS curve is then adopted for FE simulation of tensile test. The Bridgman factor or suitable plate correction factors are applied to pre and post FEA. In the load-true strain curve from FEA, the true fracture strain is determined as the matching point to test fracture load. The determined true strain is validated by comparing with test fracture strain. Finally, we complete the true SS curve by combining the prior necking part and linear part, the latter of which connects necking and predicted fracture points.

  15. Mechanical and microstructural stability of P92 steel under uniaxial tension at high temperature

    International Nuclear Information System (INIS)

    Giroux, P.F.; Dalle, F.; Sauzay, M.; Malaplate, J.; Fournier, B.; Gourgues-Lorenzon, A.F.

    2010-01-01

    9-12%Cr creep-resistant ferritic-martensitic steels are candidates for structural components of Generation IV nuclear power plants. However, they are sensitive to softening during low-cycle fatigue, creep and creep-fatigue tests, due to the destabilisation of the tempered martensite microstructure, possibly inducing a decrease in further creep resistance. To better identify the softening mechanisms in P92 steel during uniaxial deformation, tensile tests were carried out at 823 K, showing an extended and stable softening stage on true stress-strain curves after some work-hardening. Three phenomena were studied in order to understand this behaviour: mechanical instability (necking), damage and grain size evolution. Examination of fractured and non-fractured tensile specimens (light optical and electron microscopy, macrohardness) suggested that the physical mechanisms responsible for softening are mainly (sub)grain size evolution and diffuse necking. Models were proposed to predict grain growth and beginning of the mechanical instability during homogeneous deformation.

  16. Tensile properties of modified 9Cr-1Mo steel by shear punch testing and correlation with microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Karthik, V., E-mail: karthik@igcar.gov.in [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu 603102 (India); Laha, K.; Parameswaran, P.; Chandravathi, K.S.; Kasiviswanathan, K.V.; Jayakumar, T.; Raj, Baldev [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu 603102 (India)

    2011-10-15

    Modified 9Cr-1Mo ferritic steel (P91) is subjected to a series of heat treatments consisting of soaking for 5 min at the selected temperatures in the range 973 K-1623 K (below Ac{sub 1} to above Ac{sub 4}) followed by oil quenching and tempering at 1033 K for 1 h to obtain different microstructural conditions. The tensile properties of the different microstructural conditions are evaluated from small volumes of material by shear punch test technique. A new methodology for evaluating yield strength, ultimate tensile strength and strain hardening exponent from shear punch test by using correlation equations without employing empirical constants is presented and validated. The changes in the tensile properties are related to the microstructural changes of the steel investigated by electron microscopic studies. The steel exhibits minimum strength and hardness when soaked between Ac{sub 1} and Ac{sub 3} (intercritical range) temperatures due to the replacement of original lath martensitic structure with subgrains. The finer martensitic microstructure produced in the steel after soaking at temperatures above Ac{sub 3} leads to a monotonic increase in hardness and strength with decreasing strain hardening exponent. For soaking temperatures above Ac{sub 4}, the hardness and strength of the steel increases marginally due to the formation of soft {delta} ferrite. - Highlights: > A methodology presented for computing tensile properties from shear punch test. > UTS and strain hardening estimated using extended analysis of blanking models. > The analysis methodology validated for different heat treated 9Cr-1Mo steel. > Changes in tensile properties of steel correlated with microstructures.

  17. Study of austenitic stainless steel welded with low alloy steel filler metal. [tensile and impact strength tests

    Science.gov (United States)

    Burns, F. A.; Dyke, R. A., Jr.

    1979-01-01

    The tensile and impact strength properties of 316L stainless steel plate welded with low alloy steel filler metal were determined. Tests were conducted at room temperature and -100 F on standard test specimens machined from as-welded panels of various chemical compositions. No significant differences were found as the result of variations in percentage chemical composition on the impact and tensile test results. The weldments containing lower chromium and nickel as the result of dilution of parent metal from the use of the low alloy steel filler metal corroded more severely in a marine environment. The use of a protective finish, i.e., a nitrile-based paint containing aluminum powder, prevented the corrosive attack.

  18. Bonding characteristics in NiAl intermetallics with O impurity: a first-principles computational tensile test

    International Nuclear Information System (INIS)

    Hu Xuelan; Zhang Ying; Lu Guanghong; Wang Tianmin

    2009-01-01

    We have performed a first-principles computational tensile test on NiAl intermetallics with O impurity along the [001] crystalline direction on the (110) plane to investigate the tensile strength and the bonding characteristics of the NiAl-O system. We show that the ideal tensile strength is largely reduced due to the presence of O impurity in comparison with pure NiAl. The investigations of the atomic configuration and bond-length evolution show that O prefers to bond with Al, forming an O-Al cluster finally with the break of O-Ni bonds. The O-Ni bonds are demonstrated to be weaker than the O-Al bonds, and the reduced tensile strength originates from such weaker O-Ni bonds. A void-like structure forms after the break of the O-Ni and some Ni-Al bonds. Such a void-like structure can act as the initial nucleation or the propagation path of the crack, and thus produce large effects on the mechanical properties of NiAl.

  19. Tensile strength of hydrated cement paste phases assessed by microbending tests and nanoindentation

    Czech Academy of Sciences Publication Activity Database

    Němeček, J.; Králík, V.; Šmilauer, V.; Polívka, Leoš; Jäger, Aleš

    2016-01-01

    Roč. 73, Oct (2016), 164-173 ISSN 0958-9465 R&D Projects: GA ČR GBP108/12/G043 Institutional support: RVO:68378271 Keywords : cement * hydration products * micro-beam * tensile strength * fracture energy * nanoindentation * focused ion beam Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.265, year: 2016

  20. Novel MEMS Apparatus for In Situ Thermo-Mechanical Tensile Testing of Materials at the Micro- and Nano-Scale (Preprint)

    Science.gov (United States)

    2009-04-01

    outer ends of the MEMS-stage connect the stage to a macroscopic piezo -electric actuated test frame using rigid pins. In order to apply uniaxial...carbide also served as the resistor for Joule heating. This heater was used to melt glass (Soda lime glass, softening temperature: 720C, Gold Seal

  1. Ab initio tensile tests of grain boundaries in the fcc crystals of Ni and Co with segregated sp-impurities

    Czech Academy of Sciences Publication Activity Database

    Černý, Miroslav; Šešták, Petr; Řehák, Petr; Všianská, Monika; Šob, Mojmír

    2016-01-01

    Roč. 669, JUL (2016), s. 218-225 ISSN 0921-5093 R&D Projects: GA ČR(CZ) GA16-24711S; GA ČR(CZ) GAP108/12/0311; GA MŠk(CZ) LQ1601 Institutional support: RVO:68081723 Keywords : Theoretical strength * Computational tensile test * Grain boundary embrittlement * Ab initio calculations Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.094, year: 2016

  2. Specimen alignment in an axial tensile test of thin films using direct imaging and its influence on the mechanical properties of BeCu

    International Nuclear Information System (INIS)

    Kang, Dong-Joong; Park, Jun-Hyub; Shin, Myung-Soo; Ha, Jong-Eun; Lee, Hak-Joo

    2010-01-01

    This paper proposes a new system for verification of the alignment of loading fixtures and test specimens during tensile testing of thin film with a micrometer size through direct imaging. The novel and reliable image recognition system to evaluate the misalignment between the load train and the specimen axes during tensile test of thin film was developed using digital image processing technology with CCD. The decision of whether alignment of the tensile specimen is acceptable or not is based on a probabilistic analysis through the edge feature extraction of digital imaging. In order to verify the performance of the proposed system and investigate the effect of the misalignment of the specimen on tensile properties, the tensile tests were performed as displacement control in air and at room temperature for metal thin film, the beryllium copper (BeCu) alloys. In the case of the metal thin films, bending stresses caused by misalignment are insignificant because the films are easily bent during tensile tests to eliminate the bending stresses. And it was observed that little effects and scatters on tensile properties occur by stress gradient caused by twisting at in-plane misalignment, and the effects and scatters on tensile properties are insignificant at out-of-plane misalignment, in the case of the BeCu thin film.

  3. Statistical data for the tensile properties of natural fibre composites

    Directory of Open Access Journals (Sweden)

    J.P. Torres

    2017-06-01

    Full Text Available This article features a large statistical database on the tensile properties of natural fibre reinforced composite laminates. The data presented here corresponds to a comprehensive experimental testing program of several composite systems including: different material constituents (epoxy and vinyl ester resins; flax, jute and carbon fibres, different fibre configurations (short-fibre mats, unidirectional, and plain, twill and satin woven fabrics and different fibre orientations (0°, 90°, and [0,90] angle plies. For each material, ~50 specimens were tested under uniaxial tensile loading. Here, we provide the complete set of stress–strain curves together with the statistical distributions of their calculated elastic modulus, strength and failure strain. The data is also provided as support material for the research article: “The mechanical properties of natural fibre composite laminates: A statistical study” [1].

  4. Numerical Simulation on the Dynamic Splitting Tensile Test of reinforced concrete

    Science.gov (United States)

    Zhao, Zhuan; Jia, Haokai; Jing, Lin

    2018-03-01

    The research for crack resistance was of RC was based on the split Hopkinson bar and numerical simulate software LS-DYNA3D. In the research, the difference of dynamic splitting failure modes between plane concrete and reinforced concrete were completed, and the change rule of tensile stress distribution with reinforcement ratio was studied; also the effect rule with the strain rate and the crack resistance was also discussed by the radial tensile stress time history curve of RC specimen under different loading speeds. The results shows that the reinforcement in the concrete can impede the crack extension, defer the failure time of concrete, increase the tension intensity of concrete; with strain rate of concrete increased, the crack resistance of RC increased.

  5. Design and use of nonstandard tensile specimens for irradiated materials testing

    International Nuclear Information System (INIS)

    Panayotou, N.F.

    1984-10-01

    Miniature, nonstandard, tensile-type specimens have been developed for use in radiation effects experiments at high energy neutron sources where the useful radiation volume is as small as a few cubic centimeters. The end result of our development is a sheet-type specimen, 12.7 mm long with a 5.1 mm long, 1.0 mm wide gage section, which is typically fabricated from 0.25 mm thick sheet stock by a punching technique. Despite this miniature geometry, it has been determined that the data obtained using these miniature specimens are in good agreement with data obtained using much larger specimens. This finding indicates that miniature tensile specimen data may by used for engineering design purposes. Furthermore, it is clear that miniature tensile specimen technology is applicable to fields other than the study of radiation effects. This paper describes the miniature specimen technology which was developed and compares the data obtained from these miniature specimens to data obtained from much larger specimens. 9 figures

  6. Non-contact tensile viscoelastic characterization of microscale biological materials

    Science.gov (United States)

    Li, Yuhui; Hong, Yuan; Xu, Guang-Kui; Liu, Shaobao; Shi, Qiang; Tang, Deding; Yang, Hui; Genin, Guy M.; Lu, Tian Jian; Xu, Feng

    2018-06-01

    Many structures and materials in nature and physiology have important "meso-scale" structures at the micron length-scale whose tensile responses have proven difficult to characterize mechanically. Although techniques such as atomic force microscopy and micro- and nano-identation are mature for compression and indentation testing at the nano-scale, and standard uniaxial and shear rheometry techniques exist for the macroscale, few techniques are applicable for tensile-testing at the micrometre-scale, leaving a gap in our understanding of hierarchical biomaterials. Here, we present a novel magnetic mechanical testing (MMT) system that enables viscoelastic tensile testing at this critical length scale. The MMT system applies non-contact loading, avoiding gripping and surface interaction effects. We demonstrate application of the MMT system to the first analyses of the pure tensile responses of several native and engineered tissue systems at the mesoscale, showing the broad potential of the system for exploring micro- and meso-scale analysis of structured and hierarchical biological systems.

  7. Tensile Deformation Temperature Impact on Microstructure and Mechanical Properties of AISI 316LN Austenitic Stainless Steel

    Science.gov (United States)

    Xiong, Yi; He, Tiantian; Lu, Yan; Ren, Fengzhang; Volinsky, Alex A.; Cao, Wei

    2018-03-01

    Uniaxial tensile tests were conducted on AISI 316LN austenitic stainless steel from - 40 to 300 °C at a rate of 0.5 mm/min. Microstructure and mechanical properties of the deformed steel were investigated by optical, scanning and transmission electron microscopies, x-ray diffraction, and microhardness testing. The yield strength, ultimate tensile strength, elongation, and microhardness increase with the decrease in the test temperature. The tensile fracture morphology has the dimple rupture feature after low-temperature deformations and turns to a mixture of transgranular fracture and dimple fracture after high-temperature ones. The dominating deformation microstructure evolves from dislocation tangle/slip bands to large deformation twins/slip bands with temperature decrease. The deformation-induced martensite transformation can only be realized at low temperature, and its quantity increases with the decrease in the temperature.

  8. Theoretical Conversions of Different Hardness and Tensile Strength for Ductile Materials Based on Stress-Strain Curves

    Science.gov (United States)

    Chen, Hui; Cai, Li-Xun

    2018-04-01

    Based on the power-law stress-strain relation and equivalent energy principle, theoretical equations for converting between Brinell hardness (HB), Rockwell hardness (HR), and Vickers hardness (HV) were established. Combining the pre-existing relation between the tensile strength ( σ b ) and Hollomon parameters ( K, N), theoretical conversions between hardness (HB/HR/HV) and tensile strength ( σ b ) were obtained as well. In addition, to confirm the pre-existing σ b -( K, N) relation, a large number of uniaxial tensile tests were conducted in various ductile materials. Finally, to verify the theoretical conversions, plenty of statistical data listed in ASTM and ISO standards were adopted to test the robustness of the converting equations with various hardness and tensile strength. The results show that both hardness conversions and hardness-strength conversions calculated from the theoretical equations accord well with the standard data.

  9. Graphene Foam: Uniaxial Tension Behavior and Fracture Mode Based on a Mesoscopic Model.

    Science.gov (United States)

    Pan, Douxing; Wang, Chao; Wang, Tzu-Chiang; Yao, Yugui

    2017-09-26

    Because of the combined advantages of both porous materials and two-dimensional (2D) graphene sheets, superior mechanical properties of three-dimensional (3D) graphene foams have received much attention from material scientists and energy engineers. Here, a 2D mesoscopic graphene model (Modell. Simul. Mater. Sci. Eng. 2011, 19, 054003), was expanded into a 3D bonded graphene foam system by utilizing physical cross-links and van der Waals forces acting among different mesoscopic graphene flakes by considering the debonding behavior, to evaluate the uniaxial tension behavior and fracture mode based on in situ SEM tensile testing (Carbon 2015, 85, 299). We reasonably reproduced a multipeak stress-strain relationship including its obvious yielding plateau and a ductile fracture mode near 45° plane from the tensile direction including the corresponding fracture morphology. Then, a power scaling law of tensile elastic modulus with mass density and an anisotropic strain-dependent Poisson's ratio were both deduced. The mesoscopic physical mechanism of tensile deformation was clearly revealed through the local stress state and evolution of mesostructure. The fracture feature of bonded graphene foam and its thermodynamic state were directly navigated to the tearing pattern of mesoscopic graphene flakes. This study provides an effective way to understand the mesoscopic physical nature of 3D graphene foams, and hence it may contribute to the multiscale computations of micro/meso/macromechanical performances and optimal design of advanced graphene-foam-based materials.

  10. Standard Reference Development of nuclear material for Tensile and Hardness Test Properties

    International Nuclear Information System (INIS)

    Choo, Y. S.; Kim, D. S.; Yoo, B. O.; Ahn, S. B.; Baik, S. J.; Chun, Y. B.; Kim, K. H.; Hong, K. P.; Ryu, W. S.

    2007-12-01

    Standard reference is a official approved data such a coefficient of physics, approved material properties, and etc., which should be analyzed and evaluated by scientific method to acquire official approval for accuracy and credibility of measured data and information. So it could be used broadly and continuously by various fields of nation and society. It is classified to effective standard reference, verified standard reference, and certified standard reference. There are sixteen fields in designated standard references such a physical chemistry field, material field, metal field, and the others. The standard reference of neutron irradiated nuclear structural material is classified to metal field. This report summarized the whole processes about data collection, data production, data evaluation and the suggestion of details evaluation technical standard for tensile and hardness properties, which were achieved by carry out the project 'nuclear material standard reference development' as a result

  11. Standard Reference Development of nuclear material for Tensile and Hardness Test Properties

    Energy Technology Data Exchange (ETDEWEB)

    Choo, Y. S.; Kim, D. S.; Yoo, B. O.; Ahn, S. B.; Baik, S. J.; Chun, Y. B.; Kim, K. H.; Hong, K. P.; Ryu, W. S

    2007-12-15

    Standard reference is a official approved data such a coefficient of physics, approved material properties, and etc., which should be analyzed and evaluated by scientific method to acquire official approval for accuracy and credibility of measured data and information. So it could be used broadly and continuously by various fields of nation and society. It is classified to effective standard reference, verified standard reference, and certified standard reference. There are sixteen fields in designated standard references such a physical chemistry field, material field, metal field, and the others. The standard reference of neutron irradiated nuclear structural material is classified to metal field. This report summarized the whole processes about data collection, data production, data evaluation and the suggestion of details evaluation technical standard for tensile and hardness properties, which were achieved by carry out the project 'nuclear material standard reference development' as a result.

  12. Tensile properties of V-5Cr-5Ti alloy after exposure in air environment

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Soppet, W.K. [Argonne National Lab., IL (United States)

    1997-04-01

    Oxidation studies were conducted on V-5Cr-5Ti alloy specimens in an air environment to evaluate the oxygen uptake behavior of the alloy as a function of temperature and exposure time. The oxidation rates, calculated from parabolic kinetic measurements of thermogravimetric testing and confirmed by microscopic analysis of cross sections of exposed specimens, were 5, 17, and 27 {mu}m per year after exposure at 300, 400, and 500{degrees}C, respectively. Uniaxial tensile tests were conducted at room temperature and at 500{degrees}C on preoxidized specimens of the alloy to examine the effects of oxidation and oxygen migration on tensile strength and ductility. Correlations were developed between tensile strength and ductility of the oxidized alloy and microstructural characteristics such as oxide thickness, depth of hardened layer, depth of intergranular fracture zone, and transverse crack length.

  13. Derivation of tensile flow characteristics for austenitic materials from instrumented indentation technique

    International Nuclear Information System (INIS)

    Lee, K-W; Kim, K-H; Kim, J-Y; Kwon, D

    2008-01-01

    In this study, a method for deriving the tensile flow characteristics of austenitic materials from an instrumented indentation technique is presented along with its experimental verification. We proposed a modified algorithm for austenitic materials that takes their hardening behaviour into account. First, the true strain based on sine function instead of tangent function was adapted. It was proved that the sine function shows constant degrees of hardening which is a main characteristic of the hardening of austenitic materials. Second, a simple and linear constitutive equation was newly suggested to optimize indentation flow curves. The modified approach was experimentally verified by comparing tensile properties of five austenitic materials from uniaxial tensile test and instrumented indentation tests

  14. Shear punch tests performed using a new low compliance test fixture

    International Nuclear Information System (INIS)

    Toloczko, M.B.; Kurtz, R.J.; Hasegawa, A.; Abe, K.

    2002-01-01

    Based on a recent finite element analysis (FEA) study performed on the shear punch test technique, it was suggested that compliance in a test frame and fixturing which is quite acceptable for uniaxial tensile tests, is much too large for shear punch tests. The FEA study suggested that this relatively large compliance was masking both the true yield point and the shape of the load versus displacement trace obtained in shear punch tests. The knowledge gained from the FEA study was used to design a new shear punch test fixture which more directly measures punch tip displacement. The design of this fixture, the traces obtained from this fixture, and the correlation between uniaxial yield stress and shear yield stress obtained using this fixture are presented here. In general, traces obtained from the new fixture contain much less compliance resulting in a trace shape which is more similar in appearance to a corresponding uniaxial tensile trace. Due to the more direct measurement of displacement, it was possible to measure yield stress at an offset shear strain in a manner analogous to yield stress measurement in a uniaxial tensile test. The correlation between shear yield and uniaxial yield was altered by this new yield measurement technique, but the new correlation was not as greatly improved as was suggested would occur from the FEA study

  15. Strain localization during tensile Hopkinson bar testing of commercially pure titanium and Ti6Al4V titanium alloy

    Directory of Open Access Journals (Sweden)

    Moćko Wojciech

    2015-01-01

    Full Text Available The goal of the analysis was to determine the strain localization for various specimen shapes (type A and type B according to PN-EN ISO 26203-1 standard and different loading conditions, i.e. quasi- static and dynamic. Commercially pure titanium (Grade 2 and titanium alloy Ti6Al4V (Grade 5 were selected for the tests. Tensile loadings were applied out using servo-hydraulic testing machine and tensile Hopkinson bar with pre-tension. The results were recorded using ARAMIS system cameras and fast camera Phantom V1210, respectively at quasi-static and dynamic loading conditions. Further, specimens outline was determined on the basis of video data using TEMA MOTION software. The strain distribution on the specimen surface was estimated using digital image correlation method. The larger radius present in the specimen of type B in comparison to specimen of type A, results in slight increase of the elongation for commercially pure titanium at both quasi-static and dynamic loading conditions. However this effect disappears for Ti6Al4V alloy. The increase of the elongation corresponds to the stronger necking effect. Material softening due to increase of temperature induced by plastic work was observed at dynamic loading conditions. Moreover lower elongation at fracture point was found at high strain rates for both materials.

  16. A tensile machine with a novel optical load cell for soft biological tissues application.

    Science.gov (United States)

    Faturechi, Rahim; Hashemi, Ata; Abolfathi, Nabiollah

    2014-11-01

    The uniaxial tensile testing machine is the most common device used to measure the mechanical properties of industrial and biological materials. The need for a low-cost uniaxial tension testing device for small research centers has always been the subject of research. To address this need, a novel uniaxial tensile testing machine was designed and fabricated to measure the mechanical properties of soft biological tissues. The device is equipped with a new low-cost load cell which works based on the linear displacement/force relationship of beams. The deflection of the beam load cell is measured optically by a digital microscope with an accuracy of 1 µm. The stiffness of the designed load cell was experimentally and theoretically determined at 100 N mm(-1). The stiffness of the load cell can be easily adjusted according to the tissue's strength. The force-time behaviour of soft tissue specimens was obtained by an in-house image processing program. To demonstrate the efficiency of the fabricated device, the mechanical properties of amnion tissue was measured and compared with available data. The obtained results indicate a strong agreement with that of previous studies.

  17. Ultimate Tensile Strength as a Function of Test Rate for Various Ceramic Matrix Composites at Elevated Temperatures

    Science.gov (United States)

    Choi, Sung R.; Bansal, Narottam P.; Gyekenyesi, John P.

    2002-01-01

    Ultimate tensile strength of five different continuous fiber-reinforced ceramic composites, including SiC/BSAS (2D 2 types), SiC/MAS-5 (2D), SiC/SiC (2D enhanced), and C/SiC(2D) was determined as a function of test rate at I 100 to 1200 'C in air. All five composite materials exhibited a significant dependency of ultimate strength on test rate such that the ultimate strength decreased with decreasing test rate, similar to the behavior observed in many advanced monolithic ceramics at elevated temperatures. The application of the preloading technique as well as the prediction of life from one loading configuration (constant stress rate) to another (constant stress loading) for SiC/BSAS suggested that the overall macroscopic failure mechanism of the composites would be the one governed by a power-law type of damage evolution/accumulation, analogous to slow crack growth commonly observed in advanced monolithic ceramics.

  18. Interaction of heat production, strain rate and stress power in a plastically deforming body under tensile test

    Science.gov (United States)

    Paglietti, A.

    1982-01-01

    At high strain rates the heat produced by plastic deformation can give rise to a rate dependent response even if the material has rate independent constitutive equations. This effect has to be evaluated when interpreting a material test, or else it could erroneously be ascribed to viscosity. A general thermodynamic theory of tensile testing of elastic-plastic materials is given in this paper; it is valid for large strain at finite strain rates. It enables discovery of the parameters governing the thermodynamic strain rate effect, provides a method for proper interpretation of the results of the tests of dynamic plasticity, and suggests a way of planning experiments in order to detect the real contribution of viscosity.

  19. Simulation of Texture Evolution during Uniaxial Deformation of Commercially Pure Titanium

    Science.gov (United States)

    Bishoyi, B.; Debta, M. K.; Yadav, S. K.; Sabat, R. K.; Sahoo, S. K.

    2018-03-01

    The evolution of texture in commercially pure (CP) titanium during uniaxial tension and compression through VPSC (Visco-plastic self-consistent) simulation is reported in the present study. CP-titanium was subjected to both uniaxial tension and compression upto 35% deformation. During uniaxial tension, tensile twin of \\{10\\bar{1}2\\}\\unicode{x003C;}\\bar{1}011\\unicode{x003E;} type and compressive twin of \\{11\\bar{2}2\\}\\unicode{x003C;}11\\bar{2}\\bar{3}\\unicode{x003E;} type were observed in the samples. However, only tensile twin of \\{10\\bar{1}2\\}\\unicode{x003C;}\\bar{1}011\\unicode{x003E;} type and compressive twin of type was observed in the samples during uniaxial compression. Volume fractions of the twins were increased linearly as a function of percentage deformation during uniaxial tension. Whereas, during uniaxial compression the twinning volume fraction was increased up to 20% deformation and then decreased rapidly on further increasing the percentage deformation. During uniaxial tension, the general t-type textures were observed in the samples irrespective of the percentage deformation. The initial non-basal texture was oriented to split basal texture during uniaxial compression of the sample. VPSC formulation was used for simulating the texture development in the material. Different hardening parameters were estimated through correlating the simulated stress-strain curve with the experimental stress-strain data. It was observed that, prismatic slip \\{10\\bar{1}0\\}\\unicode{x003C;}11\\bar{2}0\\unicode{x003E;} operated as the primary deformation mode during uniaxial tension whereas basal slip \\{0001\\}\\unicode{x003C;}11\\bar{2}0\\unicode{x003E;} acquired the leading role during deformation through uniaxial compression. It was also revealed that active deformation modes were fully depending on percentage deformation, loading direction, and orientation of grains.

  20. Comparison of Superelasticity of Nickel Titanium Orthodontic Arch wires using Mechanical Tensile Testing and Correlating with Electrical Resistivity

    Science.gov (United States)

    Sivaraj, Aravind

    2013-01-01

    Background: Application of light and continuous forces for optimum physiological response and least damage to the tooth supporting structures should be the primary aim of the orthodontist. Nickel titanium alloys with the properties of excellent spring back, super elasticity and wide range of action is one of the natural choices for the clinicians to achieve this goal. In recent periods, various wire manufacturers have come with a variety of wires exhibiting different properties. It is the duty of the clinician to select appropriate wires during various stages of treatment for excellent results. For achieving this evaluation of the properties of these wires is essential. Materials & Methods: This study is focussed on evaluating the super elastic property of eight groups of austenite active nickel titanium wires. Eight groups of archwires bought from eight different manufacturers were studied. These wires were tested through mechanical tensile testing and electrical resistivity methods. Results: Unloading curves were carefully assessed for superelastic behaviour on deactivation. Rankings of the wires tested were based primarily upon the unloading curve’s slope Conclusion: Ortho organisers wires ranked first and superior, followed by American Orthodontics and Ormco A wires. Morelli and GAClowland NiTi wires were ranked last. It can be concluded that the performance of these wires based on rankings should be further evaluated by clinical studies. How to cite this article: Sivaraj A. Comparison of Superelasticity of Nickel Titanium Orthodontic Arch wires using Mechanical Tensile Testing and Correlating with Electrical Resistivity. J Int Oral Health 2013; 5(3):1-12. PMID:24155596

  1. Mechanical and electronic properties of monolayer and bilayer phosphorene under uniaxial and isotropic strains.

    Science.gov (United States)

    Hu, Ting; Han, Yang; Dong, Jinming

    2014-11-14

    The mechanical and electronic properties of both the monolayer and bilayer phosphorenes under either isotropic or uniaxial strain have been systematically investigated using first-principles calculations. It is interesting to find that: 1) Under a large enough isotropic tensile strain, the monolayer phosphorene would lose its pucker structure and transform into a flat hexagonal plane, while two inner sublayers of the bilayer phosphorene could be bonded due to its interlayer distance contraction. 2) Under the uniaxial tensile strain along a zigzag direction, the pucker distance of each layer in the bilayer phosphorene can exhibit a specific negative Poisson's ratio. 3) The electronic properties of both the monolayer and bilayer phosphorenes are sensitive to the magnitude and direction of the applied strains. Their band gaps decrease more rapidly under isotropic compressive strain than under uniaxial strain. Also, their direct-indirect band gap transitions happen at the larger isotropic tensile strains compared with that under uniaxial strain. 4) Under the isotropic compressive strain, the bilayer phosphorene exhibits a transition from a direct-gap semiconductor to a metal. In contrast, the monolayer phosphorene initially has the direct-indirect transition and then transitions to a metal. However, under isotropic tensile strain, both the bilayer and monolayer phosphorene show the direct-indirect transition and, finally, the transition to a metal. Our numerical results may open new potential applications of phosphorene in nanoelectronics and nanomechanical devices by external isotropic strain or uniaxial strain along different directions.

  2. Aging effects on fracture behavior of 63Sn37Pb eutectic solder during tensile tests under the SEM

    International Nuclear Information System (INIS)

    Ding Ying; Wang Chunqing; Li Mingyu; Bang Hansur

    2004-01-01

    This study investigates the influence of aging treatment on fracture behavior of Sn-Pb eutectic solder alloys at different loading rate regime during tensile tests under the scanning electron microscope. In high homologous temperature, the solder exhibit the creep behavior that could be confirmed through the phenomena of grain boundary sliding (GBS) to both as-cast and aged specimens. Owing to the large grain scale after high temperature storage, boundary behavior was limited to some extent for the difficulty in grain rotation and boundary migration. Instead, drastic intragranular deformation occurred. Also, the phase coarsening weakened the combination between lead-rich phase and tin matrix. Consequently, surface fragmentation was detected for the aged specimens. Furthermore, the fracture mechanism changed from intergranular dominated to transgranular dominated with increasing loading rate to both specimens during early stage

  3. Modeling of uniaxial ratchetting behavior of SA333 carbon manganese steel

    International Nuclear Information System (INIS)

    Shit, J.; Dhar, S.; Acharyya, S.K.; Goyal, S.

    2012-01-01

    The paper deals with uniaxial ratcheting phenomenon of cyclic plasticity behavior of the materials SA333 carbon Manganese steel. A mechanistic model for the ratcheting phenomenon has been proposed. It is observed that von Mises yield criterion together with Chaboche’s kinematic hardening rules are not sufficient to model ratcheting phenomenon. Other associated phenomena like plastic strain memory surface, back stress memory points and over all the extra hardening behavior have to be incorporated to get a complete material model for ratcheting. The proposed model assembled all these ideas together with von Mises yield criterion and Chabache’s kinematic hardening rule. Low cycle fatigue tests and uniaxial ratcheting tests have been conducted for the materials. The material constants are identified and derived from experimental results. The ratcheting coefficients have been properly calibrated with these material constants. The material model, as mentioned above, for the ratcheting phenomenon has been implemented in an elastic plastic finite element code. The ratcheting results for different stress controlled ratcheting loads have been computed. The good feature of this model is that it reduces to symmetric low cycle fatigue model when loop closes. - Highlights: ► A common material model to simulate symmetric LCF and ratcheting. ► Extra hardening to take care the shift of plastic strain centre. ► Material parameters from tensile and LCF tests. ► Saturated loop in LCF and ratcheting strain rate is compared with experiment. ► Consideration of loading path, memory path and their directions.

  4. Heat induced fracturing of rock in an existing uniaxial stress field

    International Nuclear Information System (INIS)

    Mathis, J.; Stephansson, O.; Bjarnason, B.; Hakami, H.; Herdocia, A.; Mattila, U.; Singh, U.

    1986-01-01

    This study was initiated under the premise that it may be possible to determine the state of stress in the earth's crust by heat induced fracturing of the rock surrounding a borehole. The theory involved is superficially simple, involving the superposition of the stress field around a borehole due to the existing virgin stresses and the uniform stress field of thermally loaded rock as induced by a heater. Since the heat stress field is uniform, varying only in magnitude and gradient as a function of heater input, fracturing should be controlled by the non-uniform virgin stress field. To determine if the method was, in fact, feasible, a series of laboratory test were conducted. These tests consisted of physically loading center drilled cubes of rock, 0.3 m on a side, uniaxially from 0 to 25 MPa. The blocks were then thermally loaded with a nominally rated 3.7 kW heater until failure occurred. Results from these laboratory tests were then compared to analytical studies of the problem, i.e., finite element and discrete theoretical analysis. Overall, results were such that the method is likely eliminated as a stress measurement technique. The immediate development of a thermal compressive zone on the borehole wall overlaps the tensile zone created by the uniaxial stress field, forcing the failure is thus controlled largely by the power input of the heater, being retarded by the small compressive stresses genrated by the uniaxial stress field. This small retardation effect is of such low magnitude that the retardation effect is of such low magnitude that the fracture time is relatively insensitive to the local virgin stress field. (authors)

  5. Tensile Mechanical Properties and Failure Modes of a Basalt Fiber/Epoxy Resin Composite Material

    Directory of Open Access Journals (Sweden)

    Jingjing He

    2018-01-01

    Full Text Available Uniaxial tensile tests of basalt fiber/epoxy (BF/EP composite material with four different fiber orientations were conducted under four different fiber volume fractions, and the variations of BF/EP composite material failure modes and tensile mechanical properties were analyzed. The results show that when the fiber volume fraction is constant, the tensile strength, elastic modulus, and limiting strain of BF/EP composite material all decrease with increasing fiber orientation angle. When the fiber orientation angle is constant, the tensile strength, elastic modulus, and limiting strain of BF/EP composite material all increase with increasing fiber volume fraction. A certain degree of fiber clustering appears in the epoxy resin when the basalt fiber volume fraction is >1.2%. The fiber equidistribution coefficient and clustering fiber content were used to characterize the basalt fiber clustering effect. With the increase of fiber volume fraction, the clustering fiber content gradually increased, but the fiber equidistribution coefficient decreased. Meanwhile, based on Tsai theory, a geometric model and a tensile mechanical model of the clustering fiber are established. By considering the fiber clustering effect, the BF/EP composite material tensile strength is calculated, and the calculated values are close to the experimental results.

  6. A curved beam test specimen for determining the interlaminar tensile strength of a laminated composite

    Science.gov (United States)

    Hiel, Clement C.; Sumich, Mark; Chappell, David P.

    1991-01-01

    A curved beam type of test specimen is evaluated for use in determining the through-the-thickness strength of laminated composites. Two variations of a curved beam specimen configuration (semicircular and elliptical) were tested to failure using static and fatigue loads. The static failure load for the semicircular specimens was found to be highly sensitive to flaw content, with the specimens falling into two distinct groups. This result supports the use of proof testing for structural validation. Static design allowables are derived based on the Weibull distribution. Fatigue data indicates no measured increase in specimen compliance prior to final fracture. All static and fatigue failures at room temperature dry conditions occurred catastrophically. The elliptical specimens demonstrated unusually high failure strengths indicating the presence of phenomena requiring further study. Results are also included for specimens exposed to a wet environment showing a matrix strength degradation due to moisture content. Further testing is underway to evaluate a fatigue methodology for matrix dominated failures based on residual static strength (wearout).

  7. STRAIN LOCALIZATION PECULIARITIES AND DISTRIBUTION OF ACOUSTIC EMISSION SOURCES IN ROCK SAMPLES TESTED BY UNIAXIAL COMPRESSION AND EXPOSED TO ELECTRIC PULSES

    Directory of Open Access Journals (Sweden)

    V. A. Mubassarova

    2014-01-01

    Full Text Available Results of uniaxial compression tests of rock samples in electromagnetic fields are presented. The experiments were performed in the Laboratory of Basic Physics of Strength, Institute of Continuous Media Mechanics, Ural Branch of RAS (ICMM. Deformation of samples was studied, and acoustic emission (AE signals were recorded. During the tests, loads varied by stages. Specimens of granite from the Kainda deposit in Kyrgyzstan (similar to samples tested at the Research Station of RAS, hereafter RS RAS were subject to electric pulses at specified levels of compression load. The electric pulses supply was galvanic; two graphite electrodes were fixed at opposite sides of each specimen. The multichannel Amsy-5 Vallen System was used to record AE signals in the six-channel mode, which provided for determination of spatial locations of AE sources. Strain of the specimens was studied with application of original methods of strain computation based on analyses of optical images of deformed specimen surfaces in LaVISION Strain Master System.Acoustic emission experiment data were interpreted on the basis of analyses of the AE activity in time, i.e. the number of AE events per second, and analyses of signals’ energy and AE sources’ locations, i.e. defects.The experiment was conducted at ICMM with the use of the set of equipment with advanced diagnostic capabilities (as compared to earlier experiments described in [Zakupin et al., 2006a, 2006b; Bogomolov et al., 2004]. It can provide new information on properties of acoustic emission and deformation responses of loaded rock specimens to external electric pulses.The research task also included verification of reproducibility of the effect (AE activity when fracturing rates responded to electrical pulses, which was revealed earlier in studies conducted at RS RAS. In terms of the principle of randomization, such verification is methodologically significant as new effects, i.e. physical laws, can be considered

  8. Theoretical and experimental study on unstable fracture for type 304 stainless steel plates with a soft tensile testing machine

    International Nuclear Information System (INIS)

    Yagawa, G.; Takahashi, Y.; Ando, Y.

    1981-01-01

    The object of this paper is to show experimental results on stable as well as unstable fractures for Type 304 stainless steel plates with a central crack using a soft tensile testing machine. The test machine was installed specially for the safety study of nuclear piping systems and its maximum loading capacity and maximum displacement are 600 ton and 500 mm, respectively. The compliance of the machine is 1.0 x 10 -4 (mm/N). The transition points from the stable to the unstable crack growth observed in the test were theoretically determined by using three methods. In the first method, the 'applied' value of T was calculated with the simple expression based on the dimensional analysis. In the second method, the fully-plastic solutions were used to calculate the nonlinear value of J, which was added to the linear value of J, thus the 'applied' values of T was determined by differentiating the total value of J, which was obtained for the material with the Ramberg-Osgood type stress-strain relation. In the final method, the finite element method was fully utilized to determine the 'applied' value of T. The value of J in the finite element method was obtained with the use of the path-integral. (orig./GL)

  9. Study of the concrete tensile creep: application for the containment vessel of the nuclear power plants (PWR)

    International Nuclear Information System (INIS)

    Reviron, Nanthilde

    2009-01-01

    The aim of this work is to study experimentally and to conduct numerical simulations on the creep of concrete subjected to tensile stresses. The main purpose is to predict the behaviour of containment vessels of nuclear power plants (PWR) in the case of decennial test or accident. In order to satisfy to these industrial needs, it is necessary to characterize the behaviour of concrete under uniaxial tension. Thus, an important experimental study of tensile creep in concrete has been performed for different loading levels (50%, 70% and 90% of the tensile strength). In these tests, load was kept constant during 3 days. Several tests were performed: measurements of elastic properties and strength (in tension and in compression), monitoring of drying, shrinkage, basic creep and drying creep strains. Moreover, compressive creep tests were also performed and showed a difference with tensile creep. Furthermore, decrease of tensile strength and failure under tensile creep for large loading levels were observed. A numerical model has been proposed and developed in Cast3m finite element code. (author)

  10. A study of tensile test on open-cell aluminum foam sandwich

    Science.gov (United States)

    Ibrahim, N. A.; Hazza, M. H. F. Al; Adesta, E. Y. T.; Abdullah Sidek, Atiah Bt.; Endut, N. A.

    2018-01-01

    Aluminum foam sandwich (AFS) panels are one of the growing materials in the various industries because of its lightweight behavior. AFS also known for having excellent stiffness to weight ratio and high-energy absorption. Due to their advantages, many researchers’ shows an interest in aluminum foam material for expanding the use of foam structure. However, there is still a gap need to be fill in order to develop reliable data on mechanical behavior of AFS with different parameters and analysis method approach. Least of researcher focusing on open-cell aluminum foam and statistical analysis. Thus, this research conducted by using open-cell aluminum foam core grade 6101 with aluminum sheets skin tested under tension. The data is analyzed using full factorial in JMP statistical analysis software (version 11). ANOVA result show a significant value of the model which less than 0.500. While scatter diagram and 3D plot surface profiler found that skins thickness gives a significant impact to stress/strain value compared to core thickness.

  11. Uniaxial Strain Induced Critical Current Degradation of Ag-Sheathed Bi-2212 Round Wire

    NARCIS (Netherlands)

    Dai, Chao; Qin, Jinggang; Liu, Bo; Liu, Peihang; Wu, Yu; Nijhuis, Arend; Zhou, Chao; Li, Chenshan; Hao, Qingbin; Liu, Sheng

    2018-01-01

    The critical current degradation of Bi-2212 Ag-sheathed round wire subjected to uniaxial strain was studied at 4.2 K in 14 T background field. The strains applied on the sample are both tension and compression. The additional tensile strain caused by the difference in thermal expansion between the

  12. Study of change in dispersion and orientation of clay platelets in a polymer nanocomposite during tensile test by variostage small-angle X-ray scattering

    CSIR Research Space (South Africa)

    Bandyopadhyay, J

    2012-04-01

    Full Text Available To understand the change in dispersion and orientation of clay platelets in three-dimensional space during tensile test, neat polymer and its nanocomposite samples were studied by small- and wide-angle X-ray scattering (SWAXS). The samples after...

  13. Study of twinning behavior of powder metallurgy Ti-Si alloy by interrupted in-situ tensile tests

    Energy Technology Data Exchange (ETDEWEB)

    Ye, X.X., E-mail: ye-xiaoxin@jwri.osaka-u.ac.jp [Joining and Welding Institute (JWRI), Osaka University (Japan); Imai, H.; Shen, J.H.; Chen, B. [Joining and Welding Institute (JWRI), Osaka University (Japan); Han, G.Q. [College of Materials Science and Engineering, Beijing University of Technology (China); Umeda, J.; Kondoh, K. [Joining and Welding Institute (JWRI), Osaka University (Japan)

    2017-01-02

    Twinning mechanism of powder metallurgy Ti-Si alloy was investigated by interrupted in-situ tensile tests. Extension twins {10−12}<10-1-1> in the fine-grained Ti-Si alloy were found in the uniform deformation period, but no twinning in the coarse pure Ti. Three deformation twinning nucleation mechanisms were proposed: i) local stress concentration by neighboured slip incompatibility, ii) slip/twin oriented relationship in the parent grain and iii) slip/twin transfer by high Luster-Morris oriented relationship. The interior back-stress state, grains rotation and dislocations pile-up drove the occurrence of detwinning phenomenon. Silicon-facilitation twinning verified the hypothesis that the substitutional Si solutes affected the core structures and thus the mobility of screw dislocations. Enhanced driving force and decreased energy barrier of nucleation in the micro/atomic scale were further proposed in the twinning activation. It was expected to deepen the understanding of twinning/detwinning behaviors and supply direct evidences building immature twinning mechanism. In-depth understanding about the relationship among the processing, mechanical properties and microstructure of Ti alloy was facilitated in the present work.

  14. Effect of test temperature and strain rate on the tensile properties of high-strength, high-conductivity copper alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J.; Eatherly, W.S. [Oak Ridge National Lab., TN (United States)

    1997-04-01

    The unirradiated tensile properties of wrought GlidCop AL25 (ITER grade zero, IGO) solutionized and aged CuCrZr, and cold-worked and aged and solutionized and aged Hycon 3HP{trademark} CuNiBe have been measured over the temperature range of 20-500{degrees}C at strain rates between 4 x 10{sup {minus}4} s{sup {minus}1} and 0.06 s{sup {minus}1}. The measured room temperature electrical conductivity ranged from 64 to 90% IACS for the different alloys. All of the alloys were relatively insensitive to strain rate at room temperature, but the strain rate sensitivity of GlidCop Al25 increased significantly with increasing temperature. The CuNiBe alloys exhibited the best combination of high strength and high conductivity at room temperature. The strength of CuNiBe decreased slowly with increasing temperature. However, the ductility of CuNiBe decreased rapidly with increasing temperature due to localized deformation near grain boundaries, making these alloy heats unsuitable for typical structural applications above 300{degrees}C. The strength and uniform elongation of GlidCop Al25 decreased significantly with increasing temperature at a strain rate of 1 x 10{sup {minus}3} s{sup {minus}1}, whereas the total elongation was independent of test temperature. The strength and ductility of CuCrZr decreased slowly with increasing temperature.

  15. European Fusion Programme. ITER task T23: Beryllium characterisation. Progress report. Tensile tests on neutron irradiated and reference beryllium

    International Nuclear Information System (INIS)

    Moons, F.

    1996-02-01

    As part of the European Technology Fusion Programme, the irradiation embrittlement characteristics of the more ductile and isotopic grades of beryllium manufactured by Brush Wellman has been investigated using modern powder production and consolidation techniques . This study was initiated in support of the development and evaluation of beryllium as a neutron multiplier for the solid breeder blanket design concepts proposed for a DEMO fusion power reactor. Four different species of beryllium: S-200 F (vacuum hot pressed, 1.2 wt% BeO), S-200FH (hot isostatic pressed, 0.9 wt% BeO), S-65 (vacuum hot pressed, 0.6 wt% BeO), S-65H (hot isostatic pressed, 0.5 wt% BeO) have been compared. Three batches of the beryllium have been investigated, a neutron batch, a thermal control batch and a reference batch. Neutron irradiation has been performed at temperatures between 175 and 605 degrees Celsius up to a neutron fluence of 2.1 10 25 n.m -2 (E> 1 MeV) or 750 appm He. The results of the tensile tests are summarized

  16. Tensile flow stress of ceramic particle-reinforced metal in the presence of particle cracking

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, R. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Mechanical Metallurgy, CH-1015 Lausanne (Switzerland); Rossoll, A. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Mechanical Metallurgy, CH-1015 Lausanne (Switzerland)], E-mail: andreas.rossoll@epfl.ch; Weber, L. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Mechanical Metallurgy, CH-1015 Lausanne (Switzerland); Bourke, M.A.M. [Los Alamos National Laboratory (LANL), LANSCE-12, P.O. Box 1663, MS H805, Los Alamos, NM 87545 (United States); Dunand, D.C. [Northwestern University, Department of Materials Science and Engineering, Evanston, IL 60208 (United States); Mortensen, A. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Mechanical Metallurgy, CH-1015 Lausanne (Switzerland)

    2008-10-15

    A simplified model is proposed to quantify the effect of damage in the form of particle cracking on the elastic and plastic behaviour of particle-reinforced metal matrix composites under uniaxial tensile loading: cracked particles are simply replaced, in a mean-field model, with as much matrix. Pure aluminium reinforced with 44 vol.% alumina particles, tested in tension and unloaded at periodic plastic deformations, is analysed by neutron diffraction during each reloading elastic step, at 30%, 50%, 70% and 90% of the tensile flow stress. The data give the evolution of the elastic matrix strains in the composite and also measure the progress of internal damage by particle cracking. The test gives (i) the evolution of the in situ matrix flow stress, and (ii) the evolution of load partitioning during elastic deformation with increasing composite damage. Predictions of the present model compare favourably with relevant results in the literature, and with results from the present neutron diffraction experiments.

  17. Tensile flow stress of ceramic particle-reinforced metal in the presence of particle cracking

    International Nuclear Information System (INIS)

    Mueller, R.; Rossoll, A.; Weber, L.; Bourke, M.A.M.; Dunand, D.C.; Mortensen, A.

    2008-01-01

    A simplified model is proposed to quantify the effect of damage in the form of particle cracking on the elastic and plastic behaviour of particle-reinforced metal matrix composites under uniaxial tensile loading: cracked particles are simply replaced, in a mean-field model, with as much matrix. Pure aluminium reinforced with 44 vol.% alumina particles, tested in tension and unloaded at periodic plastic deformations, is analysed by neutron diffraction during each reloading elastic step, at 30%, 50%, 70% and 90% of the tensile flow stress. The data give the evolution of the elastic matrix strains in the composite and also measure the progress of internal damage by particle cracking. The test gives (i) the evolution of the in situ matrix flow stress, and (ii) the evolution of load partitioning during elastic deformation with increasing composite damage. Predictions of the present model compare favourably with relevant results in the literature, and with results from the present neutron diffraction experiments

  18. Low cycle fatigue of 2.25Cr1Mo steel with tensile and compressed hold loading at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Junfeng; Yu, Dunji; Zhao, Zizhen; Zhang, Zhe; Chen, Gang; Chen, Xu, E-mail: xchen@tju.edu.cn

    2016-06-14

    A series of uniaxial strain-controlled fatigue and creep-fatigue tests of the bainitic 2.25Cr1Mo steel forging were performed at 455 °C in air. Three different hold periods (30 s, 120 s, 300 s) were employed at maximum tensile strain and compressive strain under fully reversed strain cycling. Both tensile and compressive holds significantly reduce the fatigue life. Fatigue life with tensile hold is shorter than that with compressive hold. A close relationship is found between the reduction of fatigue life and the amount of stress relaxation. Microstructural examination by scanning electron microscope reveals that strain hold introduces more crack sources, which can be probably ascribed to the intensified oxidation and the peeling-off of oxide layers. A modified plastic strain energy approach considering stress relaxation effect is proposed to predict the creep-fatigue life, and the predicted lives are in superior agreement with the experimental results.

  19. Tensile strength of woven yarn kenaf fiber reinforced polyester composites

    OpenAIRE

    A.E. Ismail; M.A. Che Abdul Aziz

    2015-01-01

    This paper presents the tensile strength of woven kenaf fiber reinforced polyester composites. The as-received yarn kenaf fiber is weaved and then aligned into specific fiber orientations before it is hardened with polyester resin. The composite plates are shaped according to the standard geometry and uni-axially loaded in order to investigate the tensile responses. Two important parameters are studied such as fiber orientations and number of layers. According to the results, it is shown that...

  20. Ductile fracture evaluation of ductile cast iron and forged steel by nonlinear-fracture-mechanics. Pt. 1. Tensile test by large scaled test pieces with surface crack

    International Nuclear Information System (INIS)

    Kosaki, Akio; Ajima, Tatsuro; Inohara, Yasuto

    1999-01-01

    The ductile fracture tests of Ductile Cast Iron and Forged Steel under a tensile stress condition were conducted using large-scaled flat test specimens with a surface crack and were evaluated by the J-integral values, in order to propose an evaluation method of initiation of ductile fracture of a cask body with crack by nonlinear-fracture-mechanics. Following results were obtained. 1) 1 -strain relations of Ductile Cast Iron and Forged Steel under the tensile stress condition were obtained, which is necessary for the development of J-integral design curves for evaluating the initiation of ductile fracture of the cask body. 2) In case of Ductile Cast Iron, the experimental J-integral values obtained from strain-gauges showed a good agreement with the linear-elastic-theory by Raju and Newman at room temperature, in both elastic and plastic regions. But, at 70degC in plastic region, the experimental i-integral values showed middle values between those predicted by the linear-elastic-theory and by the non- linear-elastic- theory (based on the fully plastic solution by Yagawa et al.). 3) In case of Forged Steel at both -25degC and room temperature, the experimental i-integral values obtained from strain-gauges showed a good agreement with those predicted by the linear-elastic-theory by Raju and Newman, in the elastic region. In the plastic region, however, the experimental i-integral values fell apart from the curve predicted by the linear-elastic-theory by Raju and Newman, and also approached to those by the non-linear-elastic-theory with increasing strain.(author)

  1. Nylon-6/rubber blends: 6. Notched tensile impact testing of nylon-6(ethylene-propylene rubber) blends

    NARCIS (Netherlands)

    Dijkstra, Krijn; Dijkstra, K.; ter Laak, J.A.; ter Laak, J.; Gaymans, R.J.

    1994-01-01

    The deformation and fracture behaviour of nylon-6/EPR (ethylene-propylene rubber) blends is studied as a function of strain rate and rubber content. Therefore, tensile experiments are conducted on notched specimens over a broad range of draw speeds (including strain rates as encountered in normal

  2. Comparison between uniaxially and isostatically compacted bentonite

    International Nuclear Information System (INIS)

    Kalbantner, P.; Sjoeblom, R.; Boergesson, Lennart

    2001-12-01

    The purpose of the present report is to provide the Swedish Nuclear Fuel and Waste Management Company (SKB) with the knowledge base needed for their selection of reference method for manufacturing of bentonite blocks. The purpose is also to provide support for the direction of the further development work. Three types of blocks are compared in the present report: uniaxially compacted medium high blocks, isostatically compacted medium high blocks, isostatically compacted high blocks. The analyses is based on three process systems relating to the sequence of excavation of bentonite-transport-powder preparation-compaction-handling and emplacement of bentonite blocks. The need for further knowledge has been identified and documented in conjunction with these analyses. The comparison is primarily made with regard to the criteria safety/risk, quality/ technique and economy. It is carried out through identification of issues of significance and subsequent analysis and evaluation as well as more formally in a simplified AHP (AHP = Analytical Hierarchic Process). The result of the analyses is that the isostatic technique is applicable for the production of high as well as medium size blocks. The pressed blocks are assessed to fulfil the basic requirements with a very large margin. The result of the analyses is also that the uniaxial technique is applicable for the preparation of medium size blocks, which are assessed to fulfil the basic requirements with a large margin. The need for development and process control is assessed to be somewhat higher for the uniaxial technique. One example is the friction against the walls of the die during the compaction, including the significance of this friction for the development of stresses and discontinuities in the block. These results support a selection of the isostatic technique as the reference technique as it provides flexibility in the choice of block height. The uniaxial technique can form a second alternative if medium high

  3. Evaluation of the histological and mechanical features of tendon healing in a rabbit model with the use of second-harmonic-generation imaging and tensile testing.

    Science.gov (United States)

    Hase, E; Sato, K; Yonekura, D; Minamikawa, T; Takahashi, M; Yasui, T

    2016-11-01

    This study aimed to evaluate the histological and mechanical features of tendon healing in a rabbit model with second-harmonic-generation (SHG) imaging and tensile testing. A total of eight male Japanese white rabbits were used for this study. The flexor digitorum tendons in their right leg were sharply transected, and then were repaired by intratendinous stitching. At four weeks post-operatively, the rabbits were killed and the flexor digitorum tendons in both right and left legs were excised and used as specimens for tendon healing (n = 8) and control (n = 8), respectively. Each specimen was examined by SHG imaging, followed by tensile testing, and the results of the two testing modalities were assessed for correlation. While the SHG light intensity of the healing tendon samples was significantly lower than that of the uninjured tendon samples, 2D Fourier transform SHG images showed a clear difference in collagen fibre structure between the uninjured and the healing samples, and among the healing samples. The mean intensity of the SHG image showed a moderate correlation (R 2 = 0.37) with Young's modulus obtained from the tensile testing. Our results indicate that SHG microscopy may be a potential indicator of tendon healing.Cite this article: E. Hase, K. Sato, D. Yonekura, T. Minamikawa, M. Takahashi, T. Yasui. Evaluation of the histological and mechanical features of tendon healing in a rabbit model with the use of second-harmonic-generation imaging and tensile testing. Bone Joint Res 2016;5:577-585. DOI: 10.1302/2046-3758.511.BJR-2016-0162.R1. © 2016 Yasui et al.

  4. Electronic processes in uniaxially stressed p-type germanium

    Energy Technology Data Exchange (ETDEWEB)

    Dubon, Jr., Oscar Danilo [Univ. of California, Berkeley, CA (United States)

    1996-02-01

    Effect of uniaxial stress on acceptor-related electronic processes in Ge single crystals doped with Ga, Be, and Cu were studied by Hall and photo-Hall effect measurements in conjunction with infrared spectroscopy. Stress dependence of hole lifetime in p-type Ge single crystals is used as a test for competing models of non-radiative capture of holes by acceptors. Photo-Hall effect shows that hole lifetime in Ga- and Be-doped Ge increases by over one order of magnitude with uniaxial stress at liq. He temps. Photo-Hall of Ge:Be shows a stress-induced change in the temperature dependence of hole lifetime. This is consistent with observed increase of responsivity of Ge:Ga detectors with uniaxial stress. Electronic properties of Ge:Cu are shown to change dramatically with uniaxial stress; the results provide a first explanation for the performance of uniaxially stressed, Cu-diffused Ge:Ga detectors which display a high conductivity in absence of photon signal and therefore have poor sensitivity.

  5. An evaluation of the +/-45 deg tensile test for the determination of the in-plane shear strength of composite materials

    Science.gov (United States)

    Kellas, S.; Morton, J.; Jackson, K. E.

    1991-01-01

    The applicability of the +/-45 deg tensile test for the determination of the in-plane shear strength of advanced composite laminates is studied. The assumptions used for the development of the shear strength formulas were examined, and factors such as the specimen geometry and stacking sequence were assessed experimentally. It was found that the strength of symmetric and balanced +/-45 deg laminates depends primarily upon the specimen thickness rather than the specimen width. These findings have important implications for the +/-45 deg tensile test which is recommended by several organizations for the determination of the in-plane shear stress/strain response and the shear strength of continuous fiber reinforced composites. Modifications to the recommended practices for specimen selection and shear strength determination are suggested.

  6. Determination of necking time in tensile test specimens, under high-temperature creep conditions, subjected to distribution of stresses over the cross-section

    Science.gov (United States)

    Lokoshchenko, A.; Teraud, W.

    2018-04-01

    The work describes an experimental research of creep of cylindrical tensile test specimens made of aluminum alloy D16T at a constant temperature of 400°C. The issue to be examined was the necking at different values of initial tensile stresses. The use of a developed noncontacting measuring system allowed us to see variations in the specimen shape and to estimate the true stress in various times. Based on the obtained experimental data, several criteria were proposed for describing the point of time at which the necking occurs (necking point). Calculations were carried out at various values of the parameters in these criteria. The relative interval of deformation time in which the test specimen is uniformly stretched was also determined.

  7. Status of automated tensile machine

    International Nuclear Information System (INIS)

    Satou, M.; Hamilton, M.L.; Sato, S.; Kohyama, A.

    1992-01-01

    The objective of this work is to develop the Monbusho Automated Tensile machine (MATRON) and install and operate it at the Pacific Northwest Laboratory (PNL). The machine is designed to provide rapid, automated testing of irradiated miniature tensile specimen in a vacuum at elevated temperatures. The MATRON was successfully developed and shipped to PNL for installation in a hot facility. The original installation plan was modified to simplify the current and subsequent installations, and the installation was completed. Detailed procedures governing the operation of the system were written. Testing on irradiated miniature tensile specimen should begin in the near future

  8. 2D magnetization of grain-oriented 3%-Si steel under uniaxial stress

    International Nuclear Information System (INIS)

    Permiakov, V.; Dupre, L.; Pulnikov, A.; Melkebeek, J.

    2005-01-01

    Magnetization in electrical steels is strongly affected by mechanical stress. The stress dependence of magnetic properties of non-oriented steels has been studied at one- and two-dimensional magnetization. This paper deals with the stress effect on one- and two-dimensional magnetization in grain-oriented 3%-Si steel. The special magnetic measurements system is applied to combine uniaxial stress and 2D magnetic measurements. The uniaxial stress ranges from 10 MPa compressive stress to 100 MPa tensile stress. A domain theory is a suitable tool for prediction and a physical explanation of stress dependency in grain-oriented steel

  9. Biaxial Testing of 2195 Aluminum Lithium Alloy Using Cruciform Specimens

    Science.gov (United States)

    Johnston, W. M.; Pollock, W. D.; Dawicke, D. S.; Wagner, John A. (Technical Monitor)

    2002-01-01

    A cruciform biaxial test specimen was used to test the effect of biaxial load on the yield of aluminum-lithium alloy 2195. Fifteen cruciform specimens were tested from 2 thicknesses of 2195-T8 plate, 0.45 in. and 1.75 in. These results were compared to the results from uniaxial tensile tests of the same alloy, and cruciform biaxial tests of aluminum alloy 2219-T87.

  10. The Plastic Deformation of RFSSW Joints During Tensile Tests / Deformacja Plastyczna Wybranych Połączeń RFSSW Podczas Rozciągania

    Directory of Open Access Journals (Sweden)

    Lacki P.

    2015-12-01

    Full Text Available The dynamic development of the friction stir welding (FSW technology is the basis for the design of durabe joints inter alia in the aviation industry. This technology has a prospective application, especially for the aluminum alloys. It is suitable for a broad spectrum of permanent joints. The joints obtained by FSW technology are characterized by good mechanical properties. In this paper, the friction stir spot welding joints were analysed. The example of a structure made using this technology were presented. The lap joints made of 2mm Al 6061-T6 sheets were the investigation subject. The different spot welds arrangements were analysed. The tensile test were performed with optical deformation measurement system, which allow to obtain the plastic deformation field on the sample surface. The plastic strain graphs for the characteristic line passing through the maximum deformation were registered and presented. The experimental results were compared to the FEM numerical analysis. The numerical models were built with 3D-solid elements. The boundary conditions, material properties and geometry of the joints were identical as during experimental investigation. The mechanism of deformation of welded joints during tensile test was described and explained. It has been found that the arrangement of the spot welds with respect to the tensile direction has an important influence on the behaviour and deformation of lap joint.

  11. Influence of deuterium content on tensile behavior of Zr-2.5Nb pressure tube material in the temperature range of ambient to 300 degC

    International Nuclear Information System (INIS)

    Bind, A.K.; Singh, R.N.; Chakravartty, J.K.; Dhandharia, Priyesh; Ghosh, Agnish; More, Nitin S.; Chhatre, A.G.; Vijayakumar, S.

    2011-08-01

    Tensile properties of autoclaved zirconium-2.5 wt. % niobium pressure tube material were evaluated by uniaxial tension tests at temperatures between 25 and 300 degC and under strain-rates of 1.075 x 10 -4 /s. Six number of Zr-2.5Nb alloy pressure tube spools of length 130 mm were obtained from pressure tube number 19-2557-2. Five spools were polished with abrasive paper to remove the oxide layer. These spools were gaseously charged with controlled amount of deuterium. The target deuterium concentrations were 25, 50, 75, 100 and 200 wppm of hydrogen equivalent. Ten samples were machined by EDM wire cutting from every spool. The tensile specimen axis was oriented along longitudinal direction of the tube. Metallographic examination of the deuterium charged samples suggested that the deuterides were predominantly circumferential deuterides. Analysis of tensile results showed that both yield and ultimate tensile strengths of this alloy decreased monotonically with increasing test temperatures. The tensile ductility decreased marginally with increase in test temperature from ambient to 300 degC. It was also observed that both strength and ductility appear to be unaffected by deuterium content at all temperatures, thereby suggesting that at least up to 200 wppm (Heq.) of deuterium tensile properties are not influenced by deuterium. (author)

  12. Testing Bonds Between Brittle And Ductile Films

    Science.gov (United States)

    Wheeler, Donald R.; Ohsaki, Hiroyuki

    1989-01-01

    Simple uniaxial strain test devised to measure intrinsic shear strength. Brittle film deposited on ductile stubstrate film, and combination stretched until brittle film cracks, then separates from substrate. Dimensions of cracked segments related in known way to tensile strength of brittle film and shear strength of bond between two films. Despite approximations and limitations of technique, tests show it yields semiquantitative measures of bond strengths, independent of mechanical properties of substrates, with results reproducible with plus or minus 6 percent.

  13. Modelling and Simulation of Tensile Fracture in High Velocity Compacted Metal Powder

    International Nuclear Information System (INIS)

    Jonsen, P.; Haeggblad, H.-A.

    2007-01-01

    In cold uniaxial powder compaction, powder is formed into a desired shape with rigid tools and a die. After pressing, but before sintering, the compacted powder is called green body. A critical property in the metal powder pressing process is the mechanical properties of the green body. Beyond a green body free from defects, desired properties are high strength and uniform density. High velocity compaction (HVC) using a hydraulic operated hammer is a production method to form powder utilizing a shock wave. Pre-alloyed water atomised iron powder has been HVC-formed into circular discs with high densities. The diametral compression test also called the Brazilian disc test is an established method to measure tensile strength in low strength material like e.g. rock, concrete, polymers and ceramics. During the test a thin disc is compressed across the diameter to failure. The compression induces a tensile stress perpendicular to the compressed diameter. In this study the test have been used to study crack initiation and the tensile fracture process of HVC-formed metal powder discs with a relative density of 99%. A fictitious crack model controlled by a stress versus crack-width relationship is utilized to model green body cracking. Tensile strength is used as a failure condition and limits the stress in the fracture interface. The softening rate of the model is obtained from the corresponding rate of the dissipated energy. The deformation of the powder material is modelled with an elastic-plastic Cap model. The characteristics of the tensile fracture development of the central crack in a diametrically loaded specimen is numerically studied with a three dimensional finite element simulation. Results from the finite element simulation of the diametral compression test shows that it is possible to simulate fracturing of HVC-formed powder. Results from the simulation agree reasonably with experiments

  14. Finite element analysis of steel fiber-reinforced concrete (SFRC): validation of experimental tensile capacity of dog-bone specimens

    Science.gov (United States)

    Islam, Md. Mashfiqul; Chowdhury, Md. Arman; Sayeed, Md. Abu; Hossain, Elsha Al; Ahmed, Sheikh Saleh; Siddique, Ashfia

    2014-09-01

    Finite element analyses are conducted to model the tensile capacity of steel fiber-reinforced concrete (SFRC). For this purpose dog-bone specimens are casted and tested under direct and uniaxial tension. Two types of aggregates (brick and stone) are used to cast the SFRC and plain concrete. The fiber volume ratio is maintained 1.5 %. Total 8 numbers of dog-bone specimens are made and tested in a 1000-kN capacity digital universal testing machine (UTM). The strain data are gathered employing digital image correlation technique from high-definition images and high-speed video clips. Then, the strain data are synthesized with the load data obtained from the load cell of the UTM. The tensile capacity enhancement is found 182-253 % compared to control specimen to brick SFRC and in case of stone SFRC the enhancement is 157-268 %. Fibers are found to enhance the tensile capacity as well as ductile properties of concrete that ensures to prevent sudden brittle failure. The dog-bone specimens are modeled in the ANSYS 10.0 finite element platform and analyzed to model the tensile capacity of brick and stone SFRC. The SOLID65 element is used to model the SFRC as well as plain concretes by optimizing the Poisson's ratio, modulus of elasticity, tensile strength and stress-strain relationships and also failure pattern as well as failure locations. This research provides information of the tensile capacity enhancement of SFRC made of both brick and stone which will be helpful for the construction industry of Bangladesh to introduce this engineering material in earthquake design. Last of all, the finite element outputs are found to hold good agreement with the experimental tensile capacity which validates the FE modeling.

  15. Change of residual stresses during plastic deformation under uniaxial tension test; Variacion de las tensiones residuales con la deformacion plastica en el ensayo de traccion

    Energy Technology Data Exchange (ETDEWEB)

    Benito, J. A.; Jorba, J.; Roca, A.

    2001-07-01

    Hang of longitudinal and transverse residual stresses was studied by X Ray diffraction method as the applied plastic deformation, measured as A% was increased in a standard tension test. The starting material, hot rolling Armco iron, has values close to 0 MPa in longitudinal direction. But it reaches 600 MPa with only A=1,5%, this value remains constant until necking is produced. In transverse direction the stating values are 300 MPa, changes are small and residual stresses remain compressive until the end of tension test. In addition, studies of the changes of residual stresses with time and with misalignment between incident X Ray and drawing direction are presented. (Author) 5 refs.

  16. Selective Laser Melting Produced Ti-6Al-4V: Post-Process Heat Treatments to Achieve Superior Tensile Properties

    Directory of Open Access Journals (Sweden)

    Gerrit M. Ter Haar

    2018-01-01

    Full Text Available Current post-process heat treatments applied to selective laser melting produced Ti-6Al-4V do not achieve the same microstructure and therefore superior tensile behaviour of thermomechanical processed wrought Ti-6Al-4V. Due to the growing demand for selective laser melting produced parts in industry, research and development towards improved mechanical properties is ongoing. This study is aimed at developing post-process annealing strategies to improve tensile behaviour of selective laser melting produced Ti-6Al-4V parts. Optical and electron microscopy was used to study α grain morphology as a function of annealing temperature, hold time and cooling rate. Quasi-static uniaxial tensile tests were used to measure tensile behaviour of different annealed parts. It was found that elongated α’/α grains can be fragmented into equiaxial grains through applying a high temperature annealing strategy. It is shown that bi-modal microstructures achieve a superior tensile ductility to current heat treated selective laser melting produced Ti-6Al-4V samples.

  17. Selective Laser Melting Produced Ti-6Al-4V: Post-Process Heat Treatments to Achieve Superior Tensile Properties.

    Science.gov (United States)

    Ter Haar, Gerrit M; Becker, Thorsten H

    2018-01-17

    Current post-process heat treatments applied to selective laser melting produced Ti-6Al-4V do not achieve the same microstructure and therefore superior tensile behaviour of thermomechanical processed wrought Ti-6Al-4V. Due to the growing demand for selective laser melting produced parts in industry, research and development towards improved mechanical properties is ongoing. This study is aimed at developing post-process annealing strategies to improve tensile behaviour of selective laser melting produced Ti-6Al-4V parts. Optical and electron microscopy was used to study α grain morphology as a function of annealing temperature, hold time and cooling rate. Quasi-static uniaxial tensile tests were used to measure tensile behaviour of different annealed parts. It was found that elongated α'/α grains can be fragmented into equiaxial grains through applying a high temperature annealing strategy. It is shown that bi-modal microstructures achieve a superior tensile ductility to current heat treated selective laser melting produced Ti-6Al-4V samples.

  18. Anisotropic behavior studies of aluminum alloy 5083-H0 using a micro-tensile test stage in a FEG-SEM

    CSIR Research Space (South Africa)

    Motsi, GT

    2016-02-01

    Full Text Available stream_source_info Motsi_18197_2016.pdf.txt stream_content_type text/plain stream_size 1246 Content-Encoding UTF-8 stream_name Motsi_18197_2016.pdf.txt Content-Type text/plain; charset=UTF-8 Materials Science... & Engineering A, vol. 656: 266-274 Anisotropic behavior studies of aluminum alloy 5083-H0 using a micro-tensile test stage in a FEG-SEM Motsi GT Shongwe MB Sono TJ Olubambi PA ABSTRACT: The plastic anisotropic characteristics of aluminum alloy 5083-H...

  19. Use of micro-tomography for validation of method to identify interfacial shear strength from tensile tests of short regenerated cellulose fibre composites

    DEFF Research Database (Denmark)

    Hajlane, A.; Miettinen, A.; Madsen, Bo

    2016-01-01

    The interfacial shear strength of short regenerated cellulose fibre/polylactide composites was characterized by means of an industry-friendly adhesion test method. The interfacial shear strength was back-calculated from the experimental tensile stress-strain curves of composites by using a micro......-mechanical model. The parameters characterizing the microstructure of the composites, e.g. fibre length and orientation distributions, used as input in the model were obtained by micro-tomography. The investigation was carried out on composites with untreated and surface treated fibres with various fibre weight...

  20. Design aspects of the Alpha Repository: III. Uniaxial quasi-static and creep properties of the site rock. Technical memorandum report RSI-0029

    International Nuclear Information System (INIS)

    Hansen, F.D.; Gnirk, P.F.

    1975-01-01

    Candidate mining horizons for the Alpha Repository have been tentatively selected at depths of 1,900, 2,100, and 2,700 ft in the massive salt formations underlying Eddy and Lea counties in New Mexico. The rock salt in the mining horizon at 1,900 ft exhibits average tensile and uniaxial compressive strengths of 200 and 2,445 psi, while the rock salt in the 2,700 ft horizon is 20 to 35 percent stronger. The elastic constants were essentially identical for the two horizons, with an average Young's modulus of 1.94 x 10 6 psi and a Poisson's ratio of 0.33 to 0.34. The anhydrite exhibits tensile and uniaxial compressive strengths of 830 and 13,085 psi, and its Poisson's ratio is 0.35, essentially the same as for rock salt, but its Young's modulus is 10.2 x 10 6 psi, five times greater than that of rock salt. In general, rock salt exhibits a type of bilinear stress-strain curve, with a discontinuity in slope occurring at about 750 psi. Rock salt appears to fail by crushing, rather than in an abrupt ''brittle fracture'' fashion. Anhydrite exhibits a linear stress-strain relationship, with abrupt and distinct failure at the level required for rupture. Uniaxial creep tests were performed on specimens from the 1,900 ft and 2,700 ft horizons using stress levels of 750 and 1,500 psi from 30 to over 200 hours. Results indicate that, for a constant stress level, strain is a function of time to the power of 0.20 to 0.24 and strain appears to be a nonlinear function of the deviatoric stress. Neither steady-state nor tertiary creep was observed

  1. Tensile testing of materials at high temperatures above 1700 °C with in situ synchrotron X-ray micro-tomography

    International Nuclear Information System (INIS)

    Haboub, Abdel; Nasiatka, James R.; MacDowell, Alastair A.; Bale, Hrishikesh A.; Cox, Brian N.; Marshall, David B.; Ritchie, Robert O.

    2014-01-01

    A compact ultrahigh temperature tensile testing instrument has been designed and fabricated for in situ x-ray micro-tomography using synchrotron radiation at the Advanced Light Source, Lawrence Berkeley National Laboratory. It allows for real time x-ray micro-tomographic imaging of test materials under mechanical load at temperatures up to 2300 °C in controlled environments (vacuum or controlled gas flow). Sample heating is by six infrared halogen lamps with ellipsoidal reflectors arranged in a confocal configuration, which generates an approximately spherical zone of high heat flux approximately 5 mm in diameter. Samples are held between grips connected to a motorized stage that loads the samples in tension or compression with forces up to 2.2 kN. The heating chamber and loading system are water-cooled for thermal stability. The entire instrument is mounted on a rotation stage that allows stepwise recording of radiographs over an angular range of 180°. A thin circumferential (360°) aluminum window in the wall of the heating chamber allows the x-rays to pass through the chamber and the sample over the full angular range. The performance of the instrument has been demonstrated by characterizing the evolution of 3D damage mechanisms in ceramic composite materials under tensile loading at 1750 °C

  2. Comparison of interfacial properties of electrodeposited single carbon fiber/epoxy composites using tensile and compressive fragmentation tests and acoustic emission.

    Science.gov (United States)

    Park, Joung-Man; Kim, Jin-Won; Yoon, Dong-Jin

    2002-03-01

    Interfacial and microfailure properties of carbon fiber/epoxy composites were evaluated using both tensile fragmentation and compressive Broutman tests with an aid of acoustic emission (AE). A monomeric and two polymeric coupling agents were applied via the electrodeposition (ED) and the dipping applications. A monomeric and a polymeric coupling agent showed significant and comparable improvements in interfacial shear strength (IFSS) compared to the untreated case under both tensile and compressive tests. Typical microfailure modes including cone-shaped fiber break, matrix cracking, and partial interlayer failure were observed under tension, whereas the diagonal slipped failure at both ends of the fractured fiber exhibited under compression. Adsorption and shear displacement mechanisms at the interface were described in terms of electrical attraction and primary and secondary bonding forces. For both the untreated and the treated cases AE distributions were separated well in tension, whereas AE distributions were rather closely overlapped in compression. It might be because of the difference in molecular failure energies and failure mechanisms between tension and compression. The maximum AE voltage for the waveform of either carbon or large-diameter basalt fiber breakages in tension exhibited much larger than that in compression. AE could provide more likely the quantitative information on the interfacial adhesion and microfailure.

  3. Small punch tensile/fracture test data and 3D specimen surface data on Grade 91 ferritic/martensitic steel from cryogenic to room temperature.

    Science.gov (United States)

    Bruchhausen, Matthias; Lapetite, Jean-Marc; Ripplinger, Stefan; Austin, Tim

    2016-12-01

    Raw data from small punch tensile/fracture tests at two displacement rates in the temperature range from -196 °C to room temperature on Grade 91 ferritic/martensitic steel are presented. A number of specimens were analyzed after testing by means of X-ray computed tomography (CT). Based on the CT volume data detailed 3D surface maps of the specimens were established. All data are open access and available from Online Data Information Network (ODIN)https://odin.jrc.ec.europa.eu. The data presented in the current work has been analyzed in the research article "On the determination of the ductile to brittle transition temperature from small punch tests on Grade 91 ferritic-martensitic steel" (M. Bruchhausen, S. Holmström, J.-M. Lapetite, S. Ripplinger, 2015) [1].

  4. Notch effects in uniaxial tension specimens

    International Nuclear Information System (INIS)

    Delph, T.J.

    1979-03-01

    Results of a literature survey on the effect of notches on the time-dependent failure of uniaxial tension specimens at elevated temperatures are presented. Particular attention is paid to the failure of notched specimens containing weldments

  5. Tensile strength of woven yarn kenaf fiber reinforced polyester composites

    Directory of Open Access Journals (Sweden)

    A.E. Ismail

    2015-12-01

    Full Text Available This paper presents the tensile strength of woven kenaf fiber reinforced polyester composites. The as-received yarn kenaf fiber is weaved and then aligned into specific fiber orientations before it is hardened with polyester resin. The composite plates are shaped according to the standard geometry and uni-axially loaded in order to investigate the tensile responses. Two important parameters are studied such as fiber orientations and number of layers. According to the results, it is shown that fiber orientations greatly affected the ultimate tensile strength but it is not for modulus of elasticity for both types of layers. It is estimated that the reductions of both ultimate tensile strength and Young’s modulus are in the range of 27.7-30.9% and 2.4-3.7% respectively, if the inclined fibers are used with respect to the principal axis.

  6. Tensile and compressive properties of fresh human carotid atherosclerotic plaques.

    LENUS (Irish Health Repository)

    Maher, Eoghan

    2009-12-11

    Accurate characterisation of the mechanical properties of human atherosclerotic plaque is important for our understanding of the role of vascular mechanics in the development and treatment of atherosclerosis. The majority of previous studies investigating the mechanical properties of human plaque are based on tests of plaque tissue removed following autopsy. This study aims to characterise the mechanical behaviour of fresh human carotid plaques removed during endarterectomy and tested within 2h. A total of 50 radial compressive and 17 circumferential tensile uniaxial tests were performed on samples taken from 14 carotid plaques. The clinical classification of each plaque, as determined by duplex ultrasound is also reported. Plaques were classified as calcified, mixed or echolucent. Experimental data indicated that plaques were highly inhomogeneous; with variations seen in the mechanical properties of plaque obtained from individual donors and between donors. The mean behaviour of samples for each classification indicated that calcified plaques had the stiffest response, while echolucent plaques were the least stiff. Results also indicated that there may be a difference in behaviour of samples taken from different anatomical locations (common, internal and external carotid), however the large variability indicates that more testing is needed to reach significant conclusions. This work represents a step towards a better understanding of the in vivo mechanical behaviour of human atherosclerotic plaque.

  7. Evolution of tensile design stresses for lumber

    Science.gov (United States)

    William L. Galligan; C. C. Gerhards; R. L. Ethington

    1979-01-01

    Until approximately 1965, allowable design stresses for lumber in tension were taken as equal to those assigned for bending. As interest in tensile properties increased, testing machines were designed specifically to stress lumber in tension. Research results that accumulated on tensile tests of full-size lumber suggested lower design stresses for tension than for...

  8. Recent progress in shear punch testing

    International Nuclear Information System (INIS)

    Hamilton, M.L.; Toloczko, M.B.; Lucas, G.E.

    1994-09-01

    The shear punch test was developed in response to the needs of the materials development community for small-scale mechanical properties tests. Such tests will be of great importance when a fusion neutron simulation device is built, since such a device is expected to have a limited irradiation volume. The shear punch test blanks a circular disk from a fixed sheet metal specimen, specifically a TEM disk. Load-displacement data generated during the test can be related to uniaxial tensile properties such as yield and ultimate strength. Shear punch and tensile tests were performed at room temperature on a number of unirradiated aluminum, copper, vanadium, and stainless steel alloys and on several irradiated aluminum alloys. Recent results discussed here suggest that the relationship between shear punch strength and tensile strength varies with alloy class, although the relationship determined for the unirradiated condition remains valid for the irradiated aluminum alloys

  9. Miniaturization of specimens for mechanical testing

    International Nuclear Information System (INIS)

    Harling, O.K.; Kohse, G.

    1987-01-01

    The development of mechanical property tests based on bending of a 3 mm diameter by (typically) 0.25 mm thick disk is described. Slow strain rate testing of such a disk is used to obtain tensile properties. Finite element computer modelling is used to extract yield stress values with accuracies of at least +- 10% of uniaxial tensile test values for a variety of materials. Analytical estimates of ductility from disk bend test values are possible for low-ductility materials. Work directed toward finite element calculations for ductility and ultimate tensile strength is also discussed. Preliminary data indicating the feasibility of high strain rate testing for estimation of ductile-to-brittle transition temperatures, and an example of the successful application of miniature bend testing in obtaining relative fatigue information are also presented. (author)

  10. Influence of aging treatment on deformation behavior of 96.5Sn3.5Ag lead-free solder alloy during in situ tensile tests

    International Nuclear Information System (INIS)

    Ding, Ying; Wang, Chunqing; Tian, Yanhong; Li, Mingyu

    2007-01-01

    This study investigates the influence of aging treatment on deformation behavior of 96.5Sn3.5Ag eutectic solder alloys with lower strain rate ( -3 s -1 ) during tensile tests under the scanning electron microscope. Results showed that because of the existence of Ag 3 Sn intermetallic particles and the special microstructure of β-Sn phases in Sn3.5Ag solder, grain boundary sliding was not the dominant mechanism any longer for this Pb-free solder. While the interaction of dislocations with the relatively rigid Ag 3 Sn particles began to dominate. For the as-cast specimen, accompanied by partial intragranular cracks, intergranular fracture along the grain boundaries in Sn-Ag eutectic structure or the interphase boundaries between Sn-rich dendrites and Sn-Ag eutectic phases occurred primarily in early tensile stage. However, the boundary behavior was limited by the large Ag 3 Sn particles presented along the Sn-rich dendrites boundaries after aging. Plastic flow was observed in large area, and cracks propagated in a transgranular manner across the Sn-dendrites and Sn-Ag eutectic structure

  11. Basic investigation of the laminated alginate impression technique: Setting time, permanent deformation, elastic deformation, consistency, and tensile bond strength tests.

    Science.gov (United States)

    Kitamura, Aya; Kawai, Yasuhiko

    2015-01-01

    Laminated alginate impression for edentulous is simple and time efficient compared to border molding technique. The purpose of this study was to examine clinical applicability of the laminated alginate impression, by measuring the effects of different Water/Powder (W/P) and mixing methods, and different bonding methods in the secondary impression of alginate impression. Three W/P: manufacturer-designated mixing water amount (standard), 1.5-fold (1.5×) and 1.75-fold (1.75×) water amount were mixed by manual and automatic mixing methods. Initial and complete setting time, permanent and elastic deformation, and consistency of the secondary impression were investigated (n=10). Additionally, tensile bond strength between the primary and secondary impression were measured in the following surface treatment; air blow only (A), surface baking (B), and alginate impression material bonding agent (ALGI-BOND: AB) (n=12). Initial setting times significantly shortened with automatic mixing for all W/P (p<0.05). The permanent deformation decreased and elastic deformation increased as high W/P, regardless of the mixing method. Elastic deformation significantly reduced in 1.5× and 1.75× with automatic mixing (p<0.05). All of these properties resulted within JIS standards. For all W/P, AB showed a significantly high bonding strength as compared to A and B (p<0.01). The increase of mixing water, 1.5× and 1.75×, resulted within JIS standards in setting time, suggesting its applicability in clinical setting. The use of automatic mixing device decreased elastic strain and shortening of the curing time. For the secondary impression application of adhesives on the primary impression gives secure adhesion. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  12. Determination of area reduction rate by continuous ball indentation test

    International Nuclear Information System (INIS)

    Zou, Bin; Guan, Kai Shu; Wu, Sheng Bao

    2016-01-01

    Rate of area reduction is an important mechanical property to appraise the plasticity of metals, which is always obtained from the uniaxial tensile test. A methodology is proposed to determine the area reduction rate by continuous ball indentation test technique. The continuum damage accumulation theory has been adopted in this work to identify the failure point in the indentation. The corresponding indentation depth of this point can be obtained and used to estimate the area reduction rate. The local strain limit criterion proposed in the ASME VIII-2 2007 alternative rules is also adopted in this research to convert the multiaxial strain of indentation test to uniaxial strain of tensile test. The pile-up and sink-in phenomenon which can affect the result significantly is also discussed in this paper. This method can be useful in engineering practice to evaluate the material degradation under severe working condition due to the non-destructive nature of ball indentation test. In order to validate the method, continuous ball indentation test is performed on ferritic steel 16MnR and ASTM (A193B16), then the results are compared with that got from the traditional uniaxial tensile test.

  13. Tensile deformation behavior of AA5083-H111 at cold and warm temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Ozturk, Fahrettin; Toros, Serkan; Kilic, Suleyman [Nidge Univ. (Turkey). Dept. of Mechanical Engineering

    2010-09-15

    The effects of strain rate and temperature on the deformation behavior of hardened 5083-H111 aluminum magnesium alloy sheet were investigated by performing uniaxial tensile tests at various strain rates from 0.0083 to 0.16 s{sup -1} and temperatures from -100 to 300 C. Results from the prescribed test ranges indicate that the formability of this material at cold and warm temperatures is better than at room temperature. The improvement in formability at cold temperatures is principally due to the strain hardening of the material. However, the improvement at warm temperature and low strain rate is specifically due to the high strain rate sensitivity characteristic of the material. Results indicate that this alloy should be formed at temperatures higher than 200 C and at low strain rates. (orig.)

  14. Tensile properties of orthodontic elastomeric ligatures.

    Science.gov (United States)

    Ahrari, F; Jalaly, T; Zebarjad, M

    2010-01-01

    Tensile properties of elastomeric ligatures become important when efficiency of orthodontic appliances is considered. The aim of this study was to compare tensile strength, extension to tensile strength, toughness and modulus of elasticity of elastomeric ligatures in both the as--received condition and after 28 days of immersion in the simulated oral environment. Furthermore, the changes that occurred in tensile properties of each brand of ligatures after 28 days were evaluated. Experimental-laboratory based. Elastomeric ligatures were obtained from different companies and their tensile properties were measured using Zwick testing machine in both the as-received condition and after 28 days of immersion in the simulated oral environment. The data were analyzed using independent sample t-tests, analysis of variance and Tukey tests. After 28 days, all the ligatures experienced a significant decrease in tensile strength, extension to tensile strength and toughness ( P tensile properties of different brands of ligatures in both conditions ( P tensile properties of different brands of ligatures, which should be considered during selection of these products.

  15. Assessment of strength characteristics of Al2024 ECAP metal using small punch testing

    International Nuclear Information System (INIS)

    Ma, Young Wha; Choi, Jeong Woo; Yoon, Kee Bong; Kim, Seon Hwa

    2006-01-01

    When subjected to severe shear deformation by ECAP, microstructure of Al2024 becomes extremely refined. To measure the strength of that, Small Punch(SP) testing method was adopted as a substitute for the conventional uniaxial tensile testing because the size of material processed by ECAP were limited to ψ12 mm in transverse direction. SP tests were performed with specimens in longitudinal and transverse directions of Al2024 ECAP metal. For comparing the strength values with those assessed by SP tests, uniaxial tensile tests were also conducted with specimens in longitudinal direction. Failure surfaces of the tested SP specimens showed that failure mode was shear deformation and Al2024 ECAP metal has an anisotropy in strength. Thus, conventional equations proposed for assessing the strength characteristics were improper to assess those of Al2024 ECAP metal. In this paper a way of assessing the strength of Al2024 ECAP metal was proposed and was proven to be effective

  16. Investigation of the Geometry of Metal Tube Walls after Necking in Uniaxial Tension

    Directory of Open Access Journals (Sweden)

    Chong Li

    2017-03-01

    Full Text Available Abstract: In order to characterize the deformation and true stress–strain relation of metal tubes, the geometry of tube walls after necking in uniaxial tension need to be determined. The paper investigated the necking process of metal tube. A large number of tensile tests and finite element analysis of 1Cr18Ni9Ti tubes with different sizes were conducted. It was found that the geometry of outer tube wall in the necking region can be described using a logistic regression model. The final geometry of the tube is determined by original tube diameter and wall thickness. The offset of tube walls are affected by two competing factors: volume constancy and necking. The offset distances of outer and inner walls are mainly affected by original wall thickness. The length of the necking zone is more influenced by original tube diameter. Tube elongation at fracture increases slightly as tube diameter gets larger, while the wall thickness has almost no impact on the elongation.

  17. Rapid heating tensile tests of high-energy-rate-forged 316L stainless steel containing internal helium from radioactive decay of absorbed tritium

    International Nuclear Information System (INIS)

    Mosley, W.C.

    1990-01-01

    316L stainless steel is a candidate material for construction of equipment that will be exposed to tritium. This austenitic stainless steel is frequently used in the high-energy-rate-forged (HERF) metallurgical condition to take advantage of increased strength produced by cold work introduced by this process. Proper design of tritium-handling equipment will require an understanding of how helium-3, the product of radioactive decay of tritium, affects mechanical properties. This report describes results of elevated-temperature tensile testing of HERF 316L stainless steel specimens containing helium concentrations of 171 (calculated) atomic parts per million (appm). Results are compared with those reported previously for specimens containing 0 and 94 (measured) appm helium

  18. Thermo-mechanical fatigue behaviour of the near-{gamma}-titanium aluminide alloy TNB-V5 under uniaxial and multiaxial loading

    Energy Technology Data Exchange (ETDEWEB)

    Brookes, Stephen Peter

    2009-12-19

    -strain history. The effects of TMF on the microstructure were also investigated. For all types of tests intergranular fracture is predominant. Failure is strongly influenced by environmental conditions. This study compares TMF results of TiAl with previous TMF investigations on the nickel-based alloys IN 738 and Nimonic 90. IN 738 shows similar TMF behaviour to {gamma}-TiAl in that uniaxial IP loading has the longest fatigue lifetimes. Nimonic 90 shows the opposite behaviour to both of these alloys. A lifetime model developed for this near-{gamma}-TiAl alloy, successfully describes all temperaturestrain TMF loading conditions over the test temperature range, with the use of a single loading parameter. The loading parameter is based on the plastic work per cycle, and is not only dependant on the mean tensile stress but also on the maximum principal stress. The loading parameter responds to various strain-temperature-paths differently. It describes the lifetime relation between uniaxial IP and OP loading, axial and torsional loading and the hold period effect. (orig.)

  19. Experimental study on uniaxial cyclic ratcheting behavior of 304 stainless steel at room temperature

    International Nuclear Information System (INIS)

    Yang Xianjie; Gao Qing; Cai Lixun; Liu Yujie

    2004-01-01

    The cyclic tests for 304 stainless steel with solution heat treatment under uni-axial cyclic straining and stressing were carried out systematically. The effects of the cyclic engineering stress amplitude history with constant mean stress, the mean engineering stress history with constant cyclic stress amplitude and the stress amplitude histories with the specific mean stress increment per cycle on the uni-axial ratcheting deformation behavior were investigated. Some significant results are obtained

  20. Importance of Tensile Strength on the Shear Behavior of Discontinuities

    Science.gov (United States)

    Ghazvinian, A. H.; Azinfar, M. J.; Geranmayeh Vaneghi, R.

    2012-05-01

    In this study, the shear behavior of discontinuities possessing two different rock wall types with distinct separate compressive strengths was investigated. The designed profiles consisted of regular artificial joints molded by five types of plaster mortars, each representing a distinct uniaxial compressive strength. The compressive strengths of plaster specimens ranged from 5.9 to 19.5 MPa. These specimens were molded considering a regular triangular asperity profile and were designed so as to achieve joint walls with different strength material combinations. The results showed that the shear behavior of discontinuities possessing different joint wall compressive strengths (DDJCS) tested under constant normal load (CNL) conditions is the same as those possessing identical joint wall strengths, but the shear strength of DDJCS is governed by minor joint wall compressive strength. In addition, it was measured that the predicted values obtained by Barton's empirical criterion are greater than the experimental results. The finding indicates that there is a correlation between the joint roughness coefficient (JRC), normal stress, and mechanical strength. It was observed that the mode of failure of asperities is either pure tensile, pure shear, or a combination of both. Therefore, Barton's strength criterion, which considers the compressive strength of joint walls, was modified by substituting the compressive strength with the tensile strength. The validity of the modified criterion was examined by the comparison of the predicted shear values with the laboratory shear test results reported by Grasselli (Ph.D. thesis n.2404, Civil Engineering Department, EPFL, Lausanne, Switzerland, 2001). These comparisons infer that the modified criterion can predict the shear strength of joints more precisely.

  1. Uniaxial experimental study of the acoustic emission and deformation behavior of composite rock based on 3D digital image correlation (DIC)

    Science.gov (United States)

    Cheng, Jian-Long; Yang, Sheng-Qi; Chen, Kui; Ma, Dan; Li, Feng-Yuan; Wang, Li-Ming

    2017-12-01

    In this paper, uniaxial compression tests were carried out on a series of composite rock specimens with different dip angles, which were made from two types of rock-like material with different strength. The acoustic emission technique was used to monitor the acoustic signal characteristics of composite rock specimens during the entire loading process. At the same time, an optical non-contact 3D digital image correlation technique was used to study the evolution of axial strain field and the maximal strain field before and after the peak strength at different stress levels during the loading process. The effect of bedding plane inclination on the deformation and strength during uniaxial loading was analyzed. The methods of solving the elastic constants of hard and weak rock were described. The damage evolution process, deformation and failure mechanism, and failure mode during uniaxial loading were fully determined. The experimental results show that the θ = 0{°}-45{°} specimens had obvious plastic deformation during loading, and the brittleness of the θ = 60{°}-90{°} specimens gradually increased during the loading process. When the anisotropic angle θ increased from 0{°} to 90{°}, the peak strength, peak strain, and apparent elastic modulus all decreased initially and then increased. The failure mode of the composite rock specimen during uniaxial loading can be divided into three categories: tensile fracture across the discontinuities (θ = 0{°}-30{°}), sliding failure along the discontinuities (θ = 45{°}-75{°}), and tensile-split along the discontinuities (θ = 90{°}). The axial strain of the weak and hard rock layers in the composite rock specimen during the loading process was significantly different from that of the θ = 0{°}-45{°} specimens and was almost the same as that of the θ = 60{°}-90{°} specimens. As for the strain localization highlighted in the maximum principal strain field, the θ = 0{°}-30{°} specimens appeared in the rock

  2. Biaxial direct tensile tests in a large range of strain rates. Results on a ferritic nuclear steel

    Energy Technology Data Exchange (ETDEWEB)

    Albertini, C.; Labibes, K.; Montagnani, M.; Pizzinato, E.V.; Solomos, G.; Viaccoz, B. [Commission of the European Communities, Ispra (Italy). Joint Research Centre

    2000-09-01

    Constitutive equations are usually calibrated only trough the experimental results obtained by means of unixial tests because of the lack of adequate biaxial experimental data especially at high strain rate conditions. These data are however important for the validation of analytical models and also for the predictions of mechanical behaviour of real structures subjected to multiaxial loading by numerical simulations. In this paper some developments are shown concerning biaxial cruciform specimens and different experimental machines allowing biaxial tests in a large range of strain rates. This experimental campaign has also allowed study of the influence of changing the strain paths. Diagrams of equivalent stress versus straining direction and also equivalent plastic fracture strain versus straining direction are shown. (orig.)

  3. Effect of chemistry variations on the short-term rupture life and tensile properties of 20% cold-worked type 316 stainless steel

    International Nuclear Information System (INIS)

    Duncan, D.R.; Paxton, M.M.

    1977-01-01

    The effects of compositional variations on the rupture life of 20% cold-worked Type 316 stainless steel were investigated at 19-ksi (131-MPa) uniaxial tensile stress and at 1400 0 F (1033 K). Forty-nine different alloys were studied, with compositional variations from nominal in carbon, nitrogen, phosphorus, sulfur, boron, manganese, copper, silicon, molybdenum, cobalt, chromium and nickel. This alloy and cold-work level represents the duct and fuel cladding material choice for the first four core loadings of the Fast Flux Test Facility, a key element in the Liquid-Metal Fast Breeder Reactor Program. Tensile properties of four of the alloys were studied at temperatures from room temperature to 1600 0 F (1144 K). Boron, nitrogen, and molybdenum plus silicon additions significantly increased rupture life, while chromium and carbon additions decreased rupture life. Molybdenum plus silicon additions increased yield and ultimate strength and ductility at 1200 0 F (922 K) and below

  4. The effect of strain rate and temperature on the tensile behaviour of uranium - 2sup(w)/o molybdenum

    International Nuclear Information System (INIS)

    Harding, J.; Boyd, G.A.C.

    1983-01-01

    This report describes the uniaxial tensile behaviour of uranium 2 w/o molybdenum alloy over a wide range of temperature and strain rate. Specimen blanks taken from co-reduced and extruded U2 w/o Mo rods were given one of two heat treatments. Longitudinal tensile test pieces, taken from these blanks at near surface locations were tested in the temperature range -150 deg C to +100 deg C at strain rates from quasistatic (10 -4 s -1 ) to 10 3 s -1 . To achieve this range of testing rates three machines were required: an Instron screw driven machine for rates up to 0.1 s -1 , a second specially constructed hydraulic machine for the range 0.1 s -1 to 50 s -1 and a drop weight machine for the highest strain rates. The ways in which the mechanical properties - elongation to fracture, flow stresses and ultimate tensile stress - vary with both temperature and strain rate are presented and discussed for material in both heat treatment conditions. (author)

  5. The effect of strain rate and temperature on the tensile behaviour of uranium 2 w/o molybdenum

    International Nuclear Information System (INIS)

    Harding, J.; Boyd, G.A.C.

    1983-01-01

    This report describes the uniaxial tensile behaviour of uranium 2 w/o molybdenum alloy over a wide range of temperature and strain rate. Specimen blanks taken from co-reduced and extruded U 2 w/o Mo rods were given one of two heat treatments. Longitudinal tensile test pieces, taken from these blanks at near surface locations were tested in the temperature range -150 deg C to +100 deg C at strain rates from quasistatic (10 -4 s -1 ) to 10 3 s -1 . To achieve this range of testing rates three machines were required: an Instron screw driven machine for rates up to 0.1 s -1 , a second specially constructed hydraulic machine for the range 0.1 s -1 to 50 s -1 and a drop weight machine for the highest strain rates. The ways in which the mechanical properties - elongation to fracture, flow stresses and ultimate tensile stress - vary with both temperature and strain rate are presented and discussed for material in both heat treatment conditions. (author)

  6. Kinetics of interstitial defects in α-Fe: The effect from uniaxial stress

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Changwoo [Department of Nuclear Engineering, Texas A& M University, College Station, TX 77843 (United States); Wang, Qingyu [College of Nuclear Science and Technology, Harbin Engineering University, Harbin 150001 (China); Shao, Lin, E-mail: lshao@tamu.edu [Department of Nuclear Engineering, Texas A& M University, College Station, TX 77843 (United States)

    2017-03-15

    Understanding defect kinetics in a stress field is important for multiscale modeling of materials degradation of nuclear materials. By means of molecular dynamics and molecular statics simulations, we calculate formation and migration energies of self-interstitial atoms (SIA) and SIA clusters (up to size of 5 interstitials) in alpha Fe and identify their stable configurations under uniaxial tensile strains. By applying uniaxial stress along [111], <111> oriented single SIA defects become more stable than <110> oriented SIA, which is opposite to stress-free condition. Diffusion of single SIA defects under [111] tensile stress is facilitated along [111] direction and the diffusion becomes one dimensional (1D). For SIA clusters, their diffusion under zero stress has gradual transition from three dimensional (3D) for small clusters to one dimensional (1D) for large clusters. Under the tensile stress along [111], the 3D to 1D transition is accelerated. For large SIA clusters, the stress effect is quickly saturated with less diffusivity enhancement in comparison with small SIA clusters.

  7. Effective stress coefficient for uniaxial strain condition

    DEFF Research Database (Denmark)

    Alam, M.M.; Fabricius, I.L.

    2012-01-01

    one dimensional rock mechanical deformation. We further investigated the effect of boundary condition on the stress dependency of effective stress coefficient and discussed its application in reservoir study. As stress field in the reservoirs are most unlikely to be hydrostatic, effective stress...... determined under uniaxial strain condition will be more relevant in reservoir studies. Copyright 2012 ARMA, American Rock Mechanics Association....

  8. Strain Rate Effect on Tensile Flow Behavior and Anisotropy of a Medium-Manganese TRIP Steel

    Science.gov (United States)

    Alturk, Rakan; Hector, Louis G.; Matthew Enloe, C.; Abu-Farha, Fadi; Brown, Tyson W.

    2018-06-01

    The dependence of the plastic anisotropy on the nominal strain rate for a medium-manganese (10 wt.% Mn) transformation-induced plasticity (TRIP) steel with initial austenite volume fraction of 66% (balance ferrite) has been investigated. The material exhibited yield point elongation, propagative instabilities during hardening, and austenite transformation to α'-martensite either directly or through ɛ-martensite. Uniaxial strain rates within the range of 0.005-500 s-1 along the 0°, 45°, and 90° orientations were selected based upon their relevance to automotive applications. The plastic anisotropy ( r) and normal anisotropy ( r n) indices corresponding to each direction and strain rate were determined using strain fields obtained from stereo digital image correlation systems that enabled both quasistatic and dynamic measurements. The results provide evidence of significant, orientation-dependent strain rate effects on both the flow stress and the evolution of r and r n with strain. This has implications not only for material performance during forming but also for the development of future strain-rate-dependent anisotropic yield criteria. Since tensile data alone for the subject medium-manganese TRIP steel do not satisfactorily determine the microstructural mechanisms responsible for the macroscopic-scale behavior observed on tensile testing, additional tests that must supplement the mechanical test results presented herein are discussed.

  9. An investigation of the dynamic separation of spot welds under plane tensile pulses

    International Nuclear Information System (INIS)

    Ma, Bohan; Fan, Chunlei; Chen, Danian; Wang, Huanran; Zhou, Fenghua

    2014-01-01

    We performed ultra-high-speed tests for purely opening spot welds using plane tensile pulses. A gun system generated a parallel impact of a projectile plate onto a welded plate. Induced by the interactions of the release waves, the welded plate opened purely under the plane tensile pulses. We used the laser velocity interferometer system for any reflector to measure the velocity histories of the free surfaces of the free part and the spot weld of the welded plate. We then used a scanning electron microscope to investigate the recovered welded plates. We found that the interfacial failure mode was mainly a brittle fracture and the cracks propagated through the spot nugget, while the partial interfacial failure mode was a mixed fracture comprised ductile fracture and brittle fracture. We used the measured velocity histories to evaluate the tension stresses in the free part and the spot weld of the welded plate by applying the characteristic theory. We also discussed the different constitutive behaviors of the metals under plane shock loading and under uniaxial split Hopkinson pressure bar tests. We then compared the numerically simulated velocity histories of the free surfaces of the free part and the spot weld of the welded plate with the measured results. The numerical simulations made use of the fracture stress criteria, and then the computed fracture modes of the tests were compared with the recovered results

  10. Strain Rate Effect on Tensile Flow Behavior and Anisotropy of a Medium-Manganese TRIP Steel

    Science.gov (United States)

    Alturk, Rakan; Hector, Louis G.; Matthew Enloe, C.; Abu-Farha, Fadi; Brown, Tyson W.

    2018-04-01

    The dependence of the plastic anisotropy on the nominal strain rate for a medium-manganese (10 wt.% Mn) transformation-induced plasticity (TRIP) steel with initial austenite volume fraction of 66% (balance ferrite) has been investigated. The material exhibited yield point elongation, propagative instabilities during hardening, and austenite transformation to α'-martensite either directly or through ɛ-martensite. Uniaxial strain rates within the range of 0.005-500 s-1 along the 0°, 45°, and 90° orientations were selected based upon their relevance to automotive applications. The plastic anisotropy (r) and normal anisotropy (r n) indices corresponding to each direction and strain rate were determined using strain fields obtained from stereo digital image correlation systems that enabled both quasistatic and dynamic measurements. The results provide evidence of significant, orientation-dependent strain rate effects on both the flow stress and the evolution of r and r n with strain. This has implications not only for material performance during forming but also for the development of future strain-rate-dependent anisotropic yield criteria. Since tensile data alone for the subject medium-manganese TRIP steel do not satisfactorily determine the microstructural mechanisms responsible for the macroscopic-scale behavior observed on tensile testing, additional tests that must supplement the mechanical test results presented herein are discussed.

  11. In-situ electron microscopy studies on the tensile deformation mechanisms in aluminium 5083 alloy

    CSIR Research Space (South Africa)

    Motsi, G

    2014-10-01

    Full Text Available In this study tensile deformation mechanisms of aluminium alloy 5083 were investigated under observations made from SEM equipped with a tensile stage. Observations during tensile testing revealed a sequence of surface deformation events...

  12. Textile properties of synthetic prolapse mesh in response to uniaxial loading

    Science.gov (United States)

    Barone, William R.; Moalli, Pamela A.; Abramowitch, Steven D.

    2016-01-01

    BACKGROUND Although synthetic mesh is associated with superior anatomic outcomes for the repair of pelvic organ prolapse, the benefits of mesh have been questioned because of the relatively high complication rates. To date, the mechanisms that result in such complications are poorly understood, yet the textile characteristics of mesh products are believed to play an important role. Interestingly, the pore diameter of synthetic mesh has been shown to impact the host response after hernia repair greatly, and such findings have served as design criteria for prolapse meshes, with larger pores viewed as more favorable. Although pore size and porosity are well-characterized before implantation, the changes in these textile properties after implantation are unclear; the application of mechanical forces has the potential to greatly alter pore geometries in vivo. Understanding the impact of mechanical loading on the textile properties of mesh is essential for the development of more effective devices for prolapse repair. OBJECTIVE The objective of this study was to determine the effect of tensile loading and pore orientation on mesh porosity and pore dimensions. STUDY DESIGN In this study, the porosity and pore diameter of 4 currently available prolapse meshes were examined in response to uniaxial tensile loads of 0.1, 5, and 10 N while mimicking clinical loading conditions. The textile properties were compared with those observed for the unloaded mesh. Meshes included Gynemesh PS (Ethicon, Somerville, NJ), UltraPro (Artisyn; Ethicon), Restorelle (Coloplast, Minneapolis, MN), and Alyte Y-mesh (Bard, Covington, GA). In addition to the various pore geometries, 3 orientations of Restorelle (0-, 5-, 45-degree offset) and 2 orientations of UltraPro (0-, 90-degree offset) were examined. RESULTS In response to uniaxial loading, both porosity and pore diameter dramatically decreased for most mesh products. The application of 5 N led to reductions in porosity for nearly all groups

  13. Micro-scale measurements of plastic strain field, and local contributions of slip and twinning in TWIP steels during in situ tensile tests

    Energy Technology Data Exchange (ETDEWEB)

    Yang, H.K. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Laboratoire de Mécanique des Solides, Ecole Polytechnique, CNRS UMR7649, Université Paris-Saclay, 91128 Palaiseau (France); Doquet, V., E-mail: doquet@lms.polytechnique.fr [Laboratoire de Mécanique des Solides, Ecole Polytechnique, CNRS UMR7649, Université Paris-Saclay, 91128 Palaiseau (France); Zhang, Z.F. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

    2016-08-30

    In-situ tensile tests were carried out on Fe22Mn0.6C and Fe22Mn0.6C3Al (wt%) twinning-induced plasticity (TWIP) steels specimens covered with gold micro-grids. High resolution atomic force microscopy (AFM) and scanning electron microscope (SEM) images were periodically captured. The latter were used for measurements of the plastic strain field, using digital image correlation (DIC). Although no meso-scale localization bands appeared, some areas were deformed three times more than average. Plastic deformation inside the grains was more heterogeneous in Fe22Mn0.6C, but at meso-scale, the degree of strain heterogeneity was not higher, at least up to 12% strain. Plastic deformation started from grain boundaries or annealing twin boundaries in both materials, due to a high elastic anisotropy of the grains. An original method based on DIC was developed to estimate the twin fraction in grains that exhibit a single set of slip/twin bands. Deformation twinning accommodated 60–80% of the plastic strain in some favorably oriented grains, from the onset of plastic flow in Fe22Mn0.6C, but was not observed in the Al-bearing steel until 12% strain. The back stress was important in both materials, but significantly higher in Fe22Mn0.6C.

  14. Micro-scale measurements of plastic strain field, and local contributions of slip and twinning in TWIP steels during in situ tensile tests

    International Nuclear Information System (INIS)

    Yang, H.K.; Doquet, V.; Zhang, Z.F.

    2016-01-01

    In-situ tensile tests were carried out on Fe22Mn0.6C and Fe22Mn0.6C3Al (wt%) twinning-induced plasticity (TWIP) steels specimens covered with gold micro-grids. High resolution atomic force microscopy (AFM) and scanning electron microscope (SEM) images were periodically captured. The latter were used for measurements of the plastic strain field, using digital image correlation (DIC). Although no meso-scale localization bands appeared, some areas were deformed three times more than average. Plastic deformation inside the grains was more heterogeneous in Fe22Mn0.6C, but at meso-scale, the degree of strain heterogeneity was not higher, at least up to 12% strain. Plastic deformation started from grain boundaries or annealing twin boundaries in both materials, due to a high elastic anisotropy of the grains. An original method based on DIC was developed to estimate the twin fraction in grains that exhibit a single set of slip/twin bands. Deformation twinning accommodated 60–80% of the plastic strain in some favorably oriented grains, from the onset of plastic flow in Fe22Mn0.6C, but was not observed in the Al-bearing steel until 12% strain. The back stress was important in both materials, but significantly higher in Fe22Mn0.6C.

  15. Tensile behavior of Cu50Zr50 metallic glass nanowire with a B2 crystalline precipitate

    Science.gov (United States)

    Sepulveda-Macias, Matias; Amigo, Nicolas; Gutierrez, Gonzalo

    2018-02-01

    A molecular dynamics study of the effect of a single B2-CuZr precipitate on the mechanical properties of Cu50Zr50 metallic glass nanowires is presented. Four different samples are considered: three with a 2, 4 and 6 nm radii precipitate and a precipitate-free sample. These systems are submitted to uniaxial tensile test up to 25% of strain. The interface region between the precipitate and the glass matrix has high local atomic shear strain, activating shear transformation zones, which concentrates in the neighborhood of the precipitate. The plastic regime is dominated by necking, and no localized shear band is observed for the samples with a 4 and 6 nm radii precipitate. In addition, the yield stress decreases as the size of the precipitate increases. Regarding the precipitate structure, no martensitic phase transformation is observed, since neither the shear band hit the precipitate nor the stress provided by the tensile test is enough to initiate the transformation. It is concluded that, in contrast to the case when multiple precipitates are present in the sample, a single precipitate concentrates the shear strain around its surface, eventually causing the failure of the nanowire.

  16. The theoretical tensile strength of fcc crystals predicted from shear strength calculations

    International Nuclear Information System (INIS)

    Cerny, M; Pokluda, J

    2009-01-01

    This work presents a simple way of estimating uniaxial tensile strength on the basis of theoretical shear strength calculations, taking into account its dependence on a superimposed normal stress. The presented procedure enables us to avoid complicated and time-consuming analyses of elastic stability of crystals under tensile loading. The atomistic simulations of coupled shear and tensile deformations in cubic crystals are performed using first principles computational code based on pseudo-potentials and the plane wave basis set. Six fcc crystals are subjected to shear deformations in convenient slip systems and a special relaxation procedure controls the stress tensor. The obtained dependence of the ideal shear strength on the normal tensile stress seems to be almost linearly decreasing for all investigated crystals. Taking these results into account, the uniaxial tensile strength values in three crystallographic directions were evaluated by assuming a collapse of the weakest shear system. Calculated strengths for and loading were found to be mostly lower than previously calculated stresses related to tensile instability but rather close to those obtained by means of the shear instability analysis. On the other hand, the strengths for loading almost match the stresses related to tensile instability.

  17. Cracking and Failure in Rock Specimen Containing Combined Flaw and Hole under Uniaxial Compression

    Directory of Open Access Journals (Sweden)

    Xiang Fan

    2018-01-01

    Full Text Available Flaw is a key factor influencing failure behavior of a fractured specimen. In the present study, rectangular-flawed specimens were prepared using sandstone to investigate the effect of flaw on failure behavior of rock. Open flaw and cylindrical hole were simultaneously precut within rock specimens using high-pressure water jet cutting technology. Five series of specimens including intact, single-hole-alone, two-hole-alone, single-hole and two-flaw, and two-hole and single-flaw blocks were prepared. Uniaxial compressive tests using a rigid servo control instrument were carried out to investigate the fracture processes of these flawed specimens. It is observed that during loading, internal stress always intensively distributed at both sidewalls of open hole, especially at midpoint of sidewalls, so rock crumb flaking was firstly observed among all sandstone specimens containing single hole or two holes. Cracking around open hole is associated with the flaw inclination angle which was observed in Series III and V. Crack easily initiated at the tips of flaw with inclination angles of 0°, 30°, and 60° but hard for 90° in Series III and V. Rock burst was the major failure mode among most tested specimens, which generally induced new cracks and finally created crater shape. Additionally, due to extrusion between blocks, new shear or tensile cracks were generated and the rock specimen surface spalled. Eventually, four typical failure processes including rock crumb flaking, crack initiation and propagation, rock burst, and second rupture, were summarized.

  18. Uniaxial Elongational viscosity of bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole

    2006-01-01

    The startup and steady uniaxial elongational viscosity have been measured for three bidisperse polystyrene (PS) melts, consisting of blends of monodisperse PS with molecular weights of 52 kg/mole or 103 kg/mole and 390 kg/mole. The bidisperse melts have a maximum in the steady elongational...... viscosity, of up to a factor of 7 times the Trouton limit of 3 times the zero-shear viscosity....

  19. 'Observation' of dislocation motion in single crystal and polycrystalline aluminum during uniaxial deformation using photoemission technique

    International Nuclear Information System (INIS)

    Cai, M.; Levine, L.E.; Langford, S.C.; Dickinson, J.T.

    2005-01-01

    We report measurements of photostimulated electron emission (PSE) from single-crystalline aluminum (99.995%) and high-purity polycrystalline aluminum (>99.9%) during uniaxial tensile deformation. Photoelectron intensities are sensitive to changes in surface morphology accompanying deformation, including slip line and slip band formation. In the single crystalline material, the PSE intensity increases linearly with strain. In the polycrystalline material, the PSE intensity increases exponentially with strain. In both materials, time-resolved PSE measurements show step-like increases in intensity consistent with the heterogeneous nucleation and growth of slip bands during tensile deformation. In this sense, we have 'observed' dislocation motion by this technique. Slip bands on the surfaces of deformed samples were subsequently imaged by atomic-force microscopy (AFM). Photoelectron measurements can provide reliable, quantitative information for dislocation dynamics

  20. Electrical resistivity measurement to predict uniaxial compressive ...

    Indian Academy of Sciences (India)

    Electrical resistivity values of 12 different igneous rocks were measured on core samples using a resistivity meter in the ... It was seen that the UCS and tensile strength values were linearly correlated with the ..... Innovation 2 20. Archie G E ...

  1. Smoothly varying in-plane stiffness heterogeneity evaluated under uniaxial tensile stress

    Science.gov (United States)

    J.M. Considine; F. Pierron; K.T. Turner; P. Lava; X. Tang

    2017-01-01

    Identification of spatially varying stiffness is a challenging, but important, research topic in the mechanics of materials and can provide the necessary information for material suitability, damage, and process control, especially for high‐value applications. One homogeneous and 3 heterogeneous virtual field method (VFM) formulations were used to create a methodology...

  2. The statitistical evaluation of the uniaxial compressive strength of the Ruskov andesite

    Directory of Open Access Journals (Sweden)

    Krepelka František

    2002-03-01

    Full Text Available The selection of a suitable model of the statistical distribution of the uniaxial compressive strength is discussed in the paper. The uniaxial compressive strength was studied on 180 specimens of the Ruskov andesite. The rate of loading was 1MPa.s-1. The experimental specimens had a prismatic form with a square base; the slightness ratio of specimens was 2:1. Three sets of specimens with a different length of the base edge were studied, namely 50, 30 and 10 mm. The result of the measurement were three sets with 60 values of the uniaxial compressive strength. The basic statistical parameters: the sample mean, the sample standard deviation, the variational interval, the minimum and maximum value, the sample obliqueness coefficient and the sharpness coefficient were evaluated for each collection. Two types of the distribution which can be joined with the real physical fundamentals of the desintegration of rocks ( the normal and the Weibull distribution were tested. The two-parametric Weibull distribution was tested. The basic characteristics of both distributions were evaluated for each set and the accordance of the model distribution with an experimental distribution was tested. The ÷2-test was used for testing. The two-parametric Weibull distribution was selected following the comparison of the test results of both model distributions as a suitable distribution model for the characterization of uniaxial compressive strength of the Ruskov andesite. The two-parametric Weibull distribution showed better results of the goodness-of-fit test. The normal distribution was suitable for two sets; one of the sets showed a negative result of the goodness-of-fit testing. At the uniaxial compressive strength of the Ruskov andesite, a scale effect was registered : the mean value of uniaxial compressive strength decreases with increasing the specimen base edge. This is another argument for using the Weibull distribution as a suitable statistical model of the

  3. Effects of Temperature and Strain Rate on Tensile Deformation Behavior of 9Cr-0.5Mo-1.8W-VNb Ferritic Heat-Resistant Steel

    Science.gov (United States)

    Guo, Xiaofeng; Weng, Xiaoxiang; Jiang, Yong; Gong, Jianming

    2017-09-01

    A series of uniaxial tensile tests were carried out at different strain rate and different temperatures to investigate the effects of temperature and strain rate on tensile deformation behavior of P92 steel. In the temperature range of 30-700 °C, the variations of flow stress, average work-hardening rate, tensile strength and ductility with temperature all show three temperature regimes. At intermediate temperature, the material exhibited the serrated flow behavior, the peak in flow stress, the maximum in average work-hardening rate, and the abnormal variations in tensile strength and ductility indicates the occurrence of DSA, whereas the sharp decrease in flow stress, average work-hardening rate as well as strength values, and the remarkable increase in ductility values with increasing temperature from 450 to 700 °C imply that dynamic recovery plays a dominant role in this regime. Additionally, for the temperature ranging from 550 to 650 °C, a significant decrease in flow stress values is observed with decreasing in strain rate. This phenomenon suggests the strain rate has a strong influence on flow stress. Based on the experimental results above, an Arrhenius-type constitutive equation is proposed to predict the flow stress.

  4. Influence of heat treatments on the microstructure and tensile behaviour of selective laser melting-produced TI-6AL-4V parts

    Directory of Open Access Journals (Sweden)

    Ter Haar, Gerrit Matthys

    2016-11-01

    Full Text Available In industry, post-process heat treatments of Ti-6Al-4V are performed with the aim of improving its tensile behaviour. While heat treatments of wrought Ti6Al4V have been standardised (e.g., Aerospace Material Specification H-81200, heat treatments of selective laser melting (SLM-produced Ti-6Al-4V lacks research and understanding. Significant concern exists about SLM Ti6-Al-4V’s achievable ductility attributed to its martensitic (α’ phase. In this research, heat treatments at a range of temperatures are applied to SLM-produced Ti-6Al-4V tensile samples. Microstructural analysis (both optically and through electron backscatter diffraction was used to identify links between heat treatments and microstructure. Subsequently, uniaxial tensile tests were performed to determine the respective tensile properties of all samples. Correlations in the data show a significant loss in strength with respect to an increase in annealing temperature due to grain growth, while no noticeable trend was observed for fracture strain with regard to annealing temperatures.

  5. Tensile Properties of Open Cell Ceramic Foams

    Czech Academy of Sciences Publication Activity Database

    Dlouhý, Ivo; Řehořek, Lukáš; Chlup, Zdeněk

    2009-01-01

    Roč. 409, - (2009), s. 168-175 ISSN 1013-9826. [Fractography of Advanced Ceramics /3./. Stará Lesná, 07.09.2008-10.09.2008] R&D Projects: GA ČR(CZ) GA106/06/0724; GA ČR GD106/05/H008 Institutional research plan: CEZ:AV0Z20410507 Keywords : tensile test * ceramics foam * open porosity * tensile strength Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass

  6. Tensile Behaviour of Open Cell Ceramic Foams

    Czech Academy of Sciences Publication Activity Database

    Řehořek, Lukáš; Dlouhý, Ivo; Chlup, Zdeněk

    2009-01-01

    Roč. 53, č. 4 (2009), s. 237-241 ISSN 0862-5468 R&D Projects: GA ČR GA101/09/1821; GA ČR GD106/09/H035 Institutional research plan: CEZ:AV0Z20410507 Keywords : Tensile test * Ceramics foam * Open porosity * Tensile strength Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 0.649, year: 2009

  7. Damage-induced tensile instability

    International Nuclear Information System (INIS)

    Hult, J.

    1975-01-01

    The paper presents a unified description of ductile and brittle rupture phenomena in structural components under tensile loading with particular emphasis on creep rupture. Two structural elements are analyzed in detail: 1) the uniform tensile bar subject to a Heaviside history of tensile force and superimposed such loadings, i.e. staircase histories, and 2) the thinwalled spherical pressure vessel subject to a Heaviside history of internal pressure. For both these structures the conditions for instantaneous as well as delayed rupture are analysed. It is shown that a state of mechanical instability will be reached at a certain load or after a certain time. The cases of purely ductile rupture and purely brittle fracture are identified as two limiting cases of this general instability phenomenon. The Kachanov-Rabotnov damage law implies that a structural component will fail in tension only when it has reached a state of complete damage, i.e. zero load carrying capacity. The extended law predicts failure at an earlier stage of the deterioration process and is therefore more compatible with experimental observation. Further experimental support is offered by predictions for staircase loading histories, both step-up and step-down type. The presented damage theory here predicts strain histories which are in closer agreement with test data than predictions based on other phenomenological theories

  8. Uniaxial cyclic strain enhances adipose-derived stem cell fusion with skeletal myocytes

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Jens Isak; Juhl, Morten; Nielsen, Thøger; Emmersen, Jeppe; Fink, Trine; Zachar, Vladimir; Pennisi, Cristian Pablo, E-mail: cpennisi@hst.aau.dk

    2014-07-25

    Highlights: • Uniaxial cyclic tensile strain (CTS) applied to ASCs alone or in coculture with myogenic precursors. • CTS promoted the formation of a highly ordered array of parallel ASCs. • Without biochemical supplements, CTS did not support advanced myogenic differentiation of ASCs. • Mechanical stimulation of cocultures boosted fusion of ASCs with skeletal myoblasts. - Abstract: Although adult muscle tissue possesses an exceptional capacity for regeneration, in the case of large defects, the restoration to original state is not possible. A well-known source for the de novo regeneration is the adipose-derived stem cells (ASCs), which can be readily isolated and have been shown to have a broad differentiation and regenerative potential. In this work, we employed uniaxial cyclic tensile strain (CTS), to mechanically stimulate human ASCs to participate in the formation skeletal myotubes in an in vitro model of myogenesis. The application of CTS for 48 h resulted in the formation of a highly ordered array of parallel ASCs, but failed to support skeletal muscle terminal differentiation. When the same stimulation paradigm was applied to cocultures with mouse skeletal muscle myoblasts, the percentage of ASCs contributing to the formation of myotubes significantly exceeded the levels reported in the literature hitherto. In perspective, the mechanical strain may be used to increase the efficiency of incorporation of ASCs in the skeletal muscles, which could be found useful in diverse traumatic or pathologic scenarios.

  9. Influence of a preliminary tensile plastic strain on the first stages of oxidation of a Ni80-Cr20 alloy

    International Nuclear Information System (INIS)

    Schmitt, Jean-Francois

    1992-01-01

    This research thesis reports the study of the influence of surface, and maybe also volume, defects created by a uniaxial mechanical strain on the chemical reactivity of metal and alloy surface (adsorption, desorption, segregation, surface chemical reaction), and more particularly on their early stages of oxidation. A tensile micro-machine has been designed and manufactured to study the influence of a mechanical strain on the first stages of oxidation of sample ribbons of Ni80-Cr20 alloy. Tests have been performed under low oxygen pressures. In order to analyze the surface, each reaction is monitored by Auger electron spectrometry, and many samples are transferred to another apparatus to examine the oxide distribution. Results are interpreted in terms of evolution of nickel, chromium and oxygen Auger signals which have been recorded during oxidation experiments. The first layers of the sample alloy are simply modelled and some theoretical calculations are developed which correlate with experimental values [fr

  10. Tensile properties of Zr-2.5 Nb pressure tube alloy between 25 and 800 degC

    International Nuclear Information System (INIS)

    Singh, R.N.; Kishore, R.; Sinha, T.K.; Banerjee, S.

    2000-10-01

    Tensile properties of zirconium-2.5 wt. % niobium pressure tube material were evaluated by uniaxial tension tests at temperatures between 25 and 800 degC and under strain-rates varying from 3.3 x 10 -5 to 3.3 x 10 -3 /s. Tests were carried out on specimens fabricated from the sections of finished (autoclaved) tubes as well as on those machined from the sections of cold worked (2 nd pilgered) tubes. Moreover, specimens fabricated from finished tubes belonging to twenty different heats were tested at 300 degC to study the heat to heat variation in tensile properties of this alloy. In order to study the effect of the crystallographic texture on the tensile properties, specimens oriented in longitudinal as well as, in transverse directions of the tubes were also tested. Results showed that both yield and ultimate tensile strengths of this alloy decreased monotonically with increasing test temperatures, with a rapid fall in strengths above a temperature of 350 degC (623 K). The tensile ductility did not change appreciably up to 400 degC (673K) but increased rapidly above this temperature. The observed results on the temperature dependence of the strength and ductility indicated the possible occurrence of dynamic strain-ageing in this alloy in the temperature range of 200-300 degC (473 to 573 K). The transverse specimens showed higher strengths and lower ductility as compared to those of the longitudinal specimens up to a temperature of 350 degC (623 K). Above 350 degC, the difference in the strengths and the ductility of the two types of the specimens, became negligibly small indicating that the texture did not appreciably influence the tensile properties of this alloy at temperatures exceeding 350 degC. The alloy developed extensive superplasticity (ductility exceeding 100 %), when tested in the temperature range of 650-800 degC. Maximum ductility values of 650 % for longitudinal and 900 % for the transverse orientation with strain-rate sensitivity (m) exceeding 0

  11. Uniaxial ratcheting behavior of sintered nanosilver joint for electronic packaging

    International Nuclear Information System (INIS)

    Chen, Gang; Yu, Lin; Mei, Yunhui; Li, Xin; Chen, Xu; Lu, Guo-Quan

    2014-01-01

    Uniaxial ratcheting behavior and the fatigue life of sintered nanosilver joint were investigated at room temperature. All tests were carried out under stress-controlled mode. Force–displacement data were recorded during the entire fatigue lifespan by a non-contact displacement detecting system. Effects of stress amplitude, mean stress, stress rate, and stress ratio on the uniaxial ratcheting behavior of the sintered nanosilver joint were discussed. Stress-life (S–N) curves of the sintered joints were also obtained. The Smith–Watson–Topper (SWT) model, the Gerber model and the modified Goodman model, all of which took effect of mean stress into consideration, were compared for predicting the fatigue life of the sintered joint. Both the ratcheting strain and its rate increased with increasing stress amplitude or mean stress. The increase in stress amplitude and mean stress both reduced the fatigue life of the sintered joint, while the fatigue life prolonged with the increase in stress rate and stress ratio. The modified Goodman model predicted the fatigue life of the sintered joints well

  12. Effects of tensile and compressive in-plane stress fields on adhesion in laser induced delamination experiments

    NARCIS (Netherlands)

    Fedorov, A.; Vellinga, W. P.; De Hosson, J. Th. M.

    2008-01-01

    In this work, the adhesion of a polymer coating on steel substrate subjected to uniaxial tensile plastic deformations was studied with the laser induced delamination technique. A decrease in the practical work of adhesion has been measured as the deformation of the substrate progressed. Moreover, it

  13. Impact of tensile strain on the thermal transport of zigzag hexagonal boron nitride nanoribbon: An equilibrium molecular dynamics study

    Science.gov (United States)

    Navid, Ishtiaque Ahmed; Intisar Khan, Asir; Subrina, Samia

    2018-02-01

    The thermal conductivity of single layer strained hexagonal boron nitride nanoribbon (h-BNNR) has been computed using the Green—Kubo formulation of Equilibrium Molecular Dynamics (EMD) simulation. We have investigated the impact of strain on thermal transport of h-BNNR by varying the applied tensile strain from 1% upto 5% through uniaxial loading. The thermal conductivity of h-BNNR decreases monotonically with the increase of uniaxial tensile strain keeping the sample size and temperature constant. The thermal conductivity can be reduced upto 86% for an applied uniaxial tensile strain of 5%. The impact of temperature and width variation on the thermal conductivity of h-BNNR has also been studied under different uniaxial tensile strain conditions. With the increase in temperature, the thermal conductivity of strained h-BNNR exhibits a decaying characteristics whereas it shows an opposite pattern with the increasing width. Such study would provide a good insight on the strain tunable thermal transport for the potential device application of boron nitride nanostructures.

  14. Tensile test of a silicon microstructure fully coated with submicrometer-thick diamond like carbon film using plasma enhanced chemical vapor deposition method

    Science.gov (United States)

    Zhang, Wenlei; Uesugi, Akio; Hirai, Yoshikazu; Tsuchiya, Toshiyuki; Tabata, Osamu

    2017-06-01

    This paper reports the tensile properties of single-crystal silicon (SCS) microstructures fully coated with sub-micrometer thick diamond like carbon (DLC) film using plasma enhanced chemical vapor deposition (PECVD). To minimize the deformations or damages caused by non-uniform coating of DLC, which has high compression residual stress, released SCS specimens with the dimensions of 120 µm long, 4 µm wide, and 5 µm thick were coated from the top and bottom side simultaneously. The thickness of DLC coating is around 150 nm and three different bias voltages were used for deposition. The tensile strength improved from 13.4 to 53.5% with the increasing of negative bias voltage. In addition, the deviation in strength also reduced significantly compared to bare SCS sample.

  15. A user's manual for managing database system of tensile property

    International Nuclear Information System (INIS)

    Ryu, Woo Seok; Park, S. J.; Kim, D. H.; Jun, I.

    2003-06-01

    This manual is written for the management and maintenance of the tensile database system for managing the tensile property test data. The data base constructed the data produced from tensile property test can increase the application of test results. Also, we can get easily the basic data from database when we prepare the new experiment and can produce better result by compare the previous data. To develop the database we must analyze and design carefully application and after that, we can offer the best quality to customers various requirements. The tensile database system was developed by internet method using Java, PL/SQL, JSP(Java Server Pages) tool

  16. Ion-beam texturing of uniaxially textured Ni films

    International Nuclear Information System (INIS)

    Park, S.J.; Norton, D.P.; Selvamanickam, Venkat

    2005-01-01

    The formation of biaxial texture in uniaxially textured Ni thin films via Ar-ion irradiation is reported. The ion-beam irradiation was not simultaneous with deposition. Instead, the ion beam irradiates the uniaxially textured film surface with no impinging deposition flux, which differs from conventional ion-beam-assisted deposition. The uniaxial texture is established via a nonion beam process, with the in-plane texture imposed on the uniaxial film via ion beam bombardment. Within this sequential ion beam texturing method, grain alignment is driven by selective etching and grain overgrowth

  17. Superconductivity under uniaxial compression in β-(BDA-TTP) salts

    International Nuclear Information System (INIS)

    Suzuki, T.; Onari, S.; Ito, H.; Tanaka, Y.

    2009-01-01

    In order to clarify the mechanism of organic superconductor β-(BDA-TTP) salts. We study the superconductivity under uniaxial compression with non-dimerized two-band Hubbard model. We have calculated the uniaxial compression dependence of T c by solving the Eliashberg's equation using the fluctuation exchange (FLEX) approximation. The transfer integral under the uniaxial compression was estimated by the extended Huckel method. We have found that non-monotonic behaviors of T c in experimental results under uniaxial compression are understood taking the spin frustration and spin fluctuation into account.

  18. Superconductivity under uniaxial compression in β-(BDA-TTP) salts

    Science.gov (United States)

    Suzuki, T.; Onari, S.; Ito, H.; Tanaka, Y.

    2009-10-01

    In order to clarify the mechanism of organic superconductor β-(BDA-TTP) salts. We study the superconductivity under uniaxial compression with non-dimerized two-band Hubbard model. We have calculated the uniaxial compression dependence of T c by solving the Eliashberg’s equation using the fluctuation exchange (FLEX) approximation. The transfer integral under the uniaxial compression was estimated by the extended Huckel method. We have found that non-monotonic behaviors of T c in experimental results under uniaxial compression are understood taking the spin frustration and spin fluctuation into account.

  19. Superconductivity under uniaxial compression in beta-(BDA-TTP) salts

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, T., E-mail: suzuki@rover.nuap.nagoya-u.ac.j [Department of Applied Physics and JST, TRIP, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Onari, S.; Ito, H.; Tanaka, Y. [Department of Applied Physics and JST, TRIP, Nagoya University, Chikusa, Nagoya 464-8603 (Japan)

    2009-10-15

    In order to clarify the mechanism of organic superconductor beta-(BDA-TTP) salts. We study the superconductivity under uniaxial compression with non-dimerized two-band Hubbard model. We have calculated the uniaxial compression dependence of T{sub c} by solving the Eliashberg's equation using the fluctuation exchange (FLEX) approximation. The transfer integral under the uniaxial compression was estimated by the extended Huckel method. We have found that non-monotonic behaviors of T{sub c} in experimental results under uniaxial compression are understood taking the spin frustration and spin fluctuation into account.

  20. Small-scale Specimen Testing of Monolithic U-Mo Fuel Foils

    Energy Technology Data Exchange (ETDEWEB)

    Ramprashad Prabhakaran; Douglas E. Burkes; James I. Cole; Indrajit Charit; Daniel M. Wachs

    2008-10-01

    The objective of this investigation is to develop a shear punch testing (SPT) procedure and standardize it to evaluate the mechanical properties of irradiated fuels in a hot-cell so that the tensile behavior can be predicted using small volumes of material and at greatly reduced irradiation costs. This is highly important in the development of low-enriched uranium fuels for nuclear research and test reactors. The load-displacement data obtained using SPT can be interpreted in terms of and correlated with uniaxial mechanical properties. In order to establish a correlation between SPT and tensile data, sub-size tensile and microhardness testing were performed on U-Mo alloys. In addition, efforts are ongoing to understand the effect of test parameters (such as specimen thickness, surface finish, punch-die clearance, crosshead velocity and carbon content) on the measured mechanical properties, in order to rationalize the technique, prior to employing it on a material of unknown strength.

  1. Small-scale Specimen Testing of Monolithic U-Mo Fuel Foils

    International Nuclear Information System (INIS)

    Ramprashad Prabhakaran; Douglas E. Burkes; James I. Cole; Indrajit Charit; Daniel M. Wachs

    2008-01-01

    The objective of this investigation is to develop a shear punch testing (SPT) procedure and standardize it to evaluate the mechanical properties of irradiated fuels in a hot-cell so that the tensile behavior can be predicted using small volumes of material and at greatly reduced irradiation costs. This is highly important in the development of low-enriched uranium fuels for nuclear research and test reactors. The load-displacement data obtained using SPT can be interpreted in terms of and correlated with uniaxial mechanical properties. In order to establish a correlation between SPT and tensile data, sub-size tensile and microhardness testing were performed on U-Mo alloys. In addition, efforts are ongoing to understand the effect of test parameters (such as specimen thickness, surface finish, punch-die clearance, crosshead velocity and carbon content) on the measured mechanical properties, in order to rationalize the technique, prior to employing it on a material of unknown strength

  2. Design of a cruciform bend specimen for determination of out-of- plane biaxial tensile stress effects on fracture toughness for shallow cracks

    International Nuclear Information System (INIS)

    Bass, B.R.; Bryson, J.W.; Mcafee, W.J.; Pennell, W.E.; Theiss, T.J.

    1993-01-01

    Pressurized-thermal-shock loading in a reactor pressure vessel produces significant positive out-of-plane stresses along the crack front for both circumferential and axial cracks. Experimental evidence, while very limited, seems to indicate that a reduction in toughness is associated with out-of-plane biaxial loading when compared with toughness values obtained under uniaxial conditions. A testing program is described that seeks to determine the effects of out-of-plane biaxial tensile loading on fracture toughness of RPV steels. A cruciform bend specimen that meets specified criteria for the testing pregam is analyzed using three-dimensional elastic-plastic finite-element techniques. These analysis results provide the basis for proposed test conditions that are judged likely to produce a biaxial loading effect in the cruciform bend specimen

  3. Effect of uniaxial strain on the tunnel magnetoresistance of T-shaped graphene nanoribbon based spin-valve

    Science.gov (United States)

    Fouladi, A. Ahmadi

    2016-07-01

    We theoretically investigated the spin-dependent transport through a T-shaped graphene nanoribbon (TsGNR) based spin-valve consisting of armchair graphene sandwiched between two semi-infinite ferromagnetic armchair graphene nanoribbon leads in the presence of an applied uniaxial strain. Based on a tight-binding model and standard nonequilibrium Green's function technique, it is demonstrated that the tunnel magnetoresistance (TMR) for the system can be increased about 98% by tuning the uniaxial strain. Our results show that the absolute values of TMR around the zero bias voltage for compressive strain are larger than tensile strain. In addition, the TMR of the system can be nicely controlled by GNR width.

  4. Effect of uniaxial strain on adatom diffusion across {l_brace}1 1 1{r_brace}-faceted step

    Energy Technology Data Exchange (ETDEWEB)

    Yang Jianyu, E-mail: wuliyangjianyu@yahoo.com.cn [Department of Maths and Physics, Hunan Institute of Engineering, Donghu Street, Xiangtan 411104 (China); Hu Wangyu, E-mail: Wangyuhu2001@yahoo.com.cn [Department of Applied Physics, Hunan University, Changsha 410082 (China); Tang Jianfeng [Department of Applied Physics, Hunan Agricultural University, Changsha 410128 (China)

    2011-02-01

    Diffusion of Pt adatom across the strained {l_brace}1 1 1{r_brace}-faceted step is studied by embedded atom method along with nudged elastic band method. For adatom on the flat (1 1 1) surface, the anisotropic diffusion behavior is found as the uniaxial strain is imposed. For the strained {l_brace}1 1 1{r_brace}-faceted step, our results show that the maximum energy barrier for adatom crossing step edge remains approximately constant as the strain varied from -1.0% to 1.0%, and there is a rise as the larger uniaxial strain is applied. The calculated energy barrier for adatom diffusion along the step edge increases with increasing tensile strain, and the slope of the straight line is small.

  5. Mechanical response of human female breast skin under uniaxial stretching.

    Science.gov (United States)

    Kumaraswamy, N; Khatam, Hamed; Reece, Gregory P; Fingeret, Michelle C; Markey, Mia K; Ravi-Chandar, Krishnaswamy

    2017-10-01

    Skin is a complex material covering the entire surface of the human body. Studying the mechanical properties of skin to calibrate a constitutive model is of great importance to many applications such as plastic or cosmetic surgery and treatment of skin-based diseases like decubitus ulcers. The main objective of the present study was to identify and calibrate an appropriate material constitutive model for skin and establish certain universal properties that are independent of patient-specific variability. We performed uniaxial tests performed on breast skin specimens freshly harvested during mastectomy. Two different constitutive models - one phenomenological and another microstructurally inspired - were used to interpret the mechanical responses observed in the experiments. Remarkably, we found that the model parameters that characterize dependence on previous maximum stretch (or preconditioning) exhibited specimen-independent universal behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. The test of Tensile Properties and Water Resistance of a Novel Cross-linked Starch Prepared by Adding Oil-Flax

    Science.gov (United States)

    Shi, Dawei; Wang, Rui

    2017-12-01

    In this study, to solve the poor water resistance and the low mechanical properties of starch, a mixed-starch composite matrix which including glycerol, sorbitol, and urea, were prepared via single-crew extrusion, then adding oil-flax to improve its physical mechanical and used to a source of biodegradable plastics material. The composite matrix was systematically characterized using various analytic tools including XRD, SEM and TG. The composite showed a maximum tensile strength of 18.11Mpa and moisture absorption 17.67%, while the original starch matrix was only 12.51 Mpa and 24.98%, respectively.

  7. Mechanical failure of zigzag graphene nanoribbons under tensile strain induced by edge reconstruction

    KAUST Repository

    Cheng, Yingchun

    2012-10-01

    The structural and mechanical properties of graphene nanoribbons (GNRs) under uniaxial tensile strain are studied by density functional theory. The ideal strength of a zigzag GNR (120 GPa) is close to that of pristine graphene. However, for a GNR with both edges reconstructed to pentagon–heptagon pairs (from hexagon–hexagon pairs) it decreases to 94 GPa and the maximum tensile strain is reduced to 15%. Our results constitute a comprehensive picture of the edge structure effect on the mechanical properties of GNRs.

  8. Mechanical failure of zigzag graphene nanoribbons under tensile strain induced by edge reconstruction

    KAUST Repository

    Cheng, Yingchun; Schwingenschlö gl, Udo; Zhu, Zhiyong

    2012-01-01

    The structural and mechanical properties of graphene nanoribbons (GNRs) under uniaxial tensile strain are studied by density functional theory. The ideal strength of a zigzag GNR (120 GPa) is close to that of pristine graphene. However, for a GNR with both edges reconstructed to pentagon–heptagon pairs (from hexagon–hexagon pairs) it decreases to 94 GPa and the maximum tensile strain is reduced to 15%. Our results constitute a comprehensive picture of the edge structure effect on the mechanical properties of GNRs.

  9. 2D Electron Gas with 100% Spin-Polarization in the (LaMnO3)2/(SrTiO3)2 Superlattice under Uniaxial Strain

    KAUST Repository

    Cossu, Fabrizio

    2014-07-28

    By first-principles calculations we investigate the structural, electronic, and magnetic properties of the (LaMnO3)2/(SrTiO3)2 superlattice. We find that a monoclinic C2h symmetry is energetically favorable and that the spins order ferromagnetically. Under both compressive and tensile uniaxial strain the electronic structure of the superlattice shows a half-metallic character. In particular, a fully spin-polarized two-dimensional electron gas, which traces back to the Ti 3dxy orbitals, is achieved under compressive uniaxial strain. The (LaMnO3)2/(SrTiO3)2 superlattice is analysed with respect to its structure, magnetism, and electronic properties. Our results demonstrate that uniaxial strain in an experimentally accessible range, both tensile and compressive, can be used to induce half-metallicity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Bending and tensile deformation of metallic nanowires

    International Nuclear Information System (INIS)

    McDowell, Matthew T; Leach, Austin M; Gall, Ken

    2008-01-01

    Using molecular statics simulations and the embedded atom method, a technique for bending silver nanowires and calculating Young's modulus via continuum mechanics has been developed. The measured Young's modulus values extracted from bending simulations were compared with modulus values calculated from uniaxial tension simulations for a range of nanowire sizes, orientations and geometries. Depending on axial orientation, the nanowires exhibit stiffening or softening under tension and bending as size decreases. Bending simulations typically result in a greater variation of Young's modulus values with nanowire size compared with tensile deformation, which indicates a loading-method-dependent size effect on elastic properties at sub-5 nm wire diameters. Since the axial stress is maximized at the lateral surfaces in bending, the loading-method-dependent size effect is postulated to be primarily a result of differences in nanowire surface and core elastic modulus. The divergence of Young's modulus from the bulk modulus in these simulations occurs at sizes below the range in which experiments have demonstrated a size scale effect on elastic properties of metallic nanowires. This difference indicates that other factors beyond native metallic surface properties play a role in experimentally observed nanowire elastic modulus size effects

  11. Observation austenite memory and significant enhancement of tensile properties during cyclic reverse martensite transformation in a Fe-Ni-C TRIP steel

    Energy Technology Data Exchange (ETDEWEB)

    Alaei, Aida; Jafarian, Hamidreza, E-mail: jafarian@iust.ac.ir; Eivani, Ali Reza

    2016-10-31

    In this study, the influence of reverse martensite transformation (reverse transformation) on microstructure development and mechanical properties of Fe-24Ni-0.3C metastable austenitic TRIP steel was investigated. Microstructural characterization by electron backscatter diffraction (EBSD) system proved that large amount of low angle boundaries appeared after 1-cycle of reverse transformation (γ→α→γ). It is also found that the 1-cycle reversely transformed austenite and original austenite exhibited similar shape, size and orientations indicating that austenite memory appeared during reverse transformation. By increasing the number of reverse transformation cycle, fraction of low angle boundaries significantly increased. Uniaxial tensile test exhibited that yield and ultimate tensile strengths significantly improved even by 1-cycle reverse transformation comparing to the starting material. In addition, further continuation of reverse transformation up to 5- or 7-cycle causes gradual increase in yield and ultimate tensile strengths as well. The significant improvement in yield strength should be originated from increasing the dislocation density that are introduced during reverse transformation.

  12. Developing of tensile property database system

    International Nuclear Information System (INIS)

    Park, S. J.; Kim, D. H.; Jeon, J.; Ryu, W. S.

    2002-01-01

    The data base construction using the data produced from tensile experiment can increase the application of test results. Also, we can get the basic data ease from database when we prepare the new experiment and can produce high quality result by compare the previous data. The development part must be analysis and design more specific to construct the database and after that, we can offer the best quality to customers various requirements. In this thesis, the tensile database system was developed by internet method using JSP(Java Server pages) tool

  13. Tensile and shear strength of adhesives

    Science.gov (United States)

    Stibolt, Kenneth A.

    1990-01-01

    This experiment is conducted in a freshman-level course: Introduction to Engineering Materials. There are no prerequisites for the course although students should have some knowledge of basic algebra. The objectives are to tension and shear test adhesives and to determine the tensile and shear properties of adhesives. Details of equipment of procedure are given.

  14. Tensile Strength of the Eggshell Membranes

    Czech Academy of Sciences Publication Activity Database

    Strnková, J.; Nedomová, Š.; Kumbár, V.; Trnka, Jan

    2016-01-01

    Roč. 64, č. 1 (2016), s. 159-164 ISSN 1211-8516 Institutional research plan: CEZ:AV0Z20760514 Institutional support: RVO:61388998 Keywords : eggshell membrane * tesile test * loading rate * tensile strength * fracture strain Subject RIV: GM - Food Processing

  15. High-Tensile Strength Tape Versus High-Tensile Strength Suture: A Biomechanical Study.

    Science.gov (United States)

    Gnandt, Ryan J; Smith, Jennifer L; Nguyen-Ta, Kim; McDonald, Lucas; LeClere, Lance E

    2016-02-01

    To determine which suture design, high-tensile strength tape or high-tensile strength suture, performed better at securing human tissue across 4 selected suture techniques commonly used in tendinous repair, by comparing the total load at failure measured during a fixed-rate longitudinal single load to failure using a biomechanical testing machine. Matched sets of tendon specimens with bony attachments were dissected from 15 human cadaveric lower extremities in a manner allowing for direct comparison testing. With the use of selected techniques (simple Mason-Allen in the patellar tendon specimens, whip stitch in the quadriceps tendon specimens, and Krackow stitch in the Achilles tendon specimens), 1 sample of each set was sutured with a 2-mm braided, nonabsorbable, high-tensile strength tape and the other with a No. 2 braided, nonabsorbable, high-tensile strength suture. A total of 120 specimens were tested. Each model was loaded to failure at a fixed longitudinal traction rate of 100 mm/min. The maximum load and failure method were recorded. In the whip stitch and the Krackow-stitch models, the high-tensile strength tape had a significantly greater mean load at failure with a difference of 181 N (P = .001) and 94 N (P = .015) respectively. No significant difference was found in the Mason-Allen and simple stitch models. Pull-through remained the most common method of failure at an overall rate of 56.7% (suture = 55%; tape = 58.3%). In biomechanical testing during a single load to failure, high-tensile strength tape performs more favorably than high-tensile strength suture, with a greater mean load to failure, in both the whip- and Krackow-stitch models. Although suture pull-through remains the most common method of failure, high-tensile strength tape requires a significantly greater load to pull-through in a whip-stitch and Krakow-stitch model. The biomechanical data obtained in the current study indicates that high-tensile strength tape may provide better repair

  16. Hot Tensile and Fracture Behavior of 35CrMo Steel at Elevated Temperature and Strain Rate

    Directory of Open Access Journals (Sweden)

    Zhengbing Xiao

    2016-08-01

    Full Text Available To better understand the tensile deformation and fracture behavior of 35CrMo steel during hot processing, uniaxial tensile tests at elevated temperatures and strain rates were performed. Effects of deformation condition on the flow behavior, strain rate sensitivity, microstructure transformation, and fracture characteristic were characterized and discussed. The results indicated that the flow stress was sensitive to the deformation condition, and fracture occurs immediately after the peak stress level is reached, especially when the temperature is low or the strain rate is high. The strain rate sensitivity increases with the deformation temperature, which indicates that formability could improve at high temperatures. Photographs showing both the fracture surfaces and the matrix near the fracture section indicated the ductile nature of the material. However, the fracture mechanisms varied according to the deformation condition, which influences the dynamic recrystallization (DRX condition, and the DRX was accompanied by the formation of voids. For samples deformed at high temperatures or low strain rates, coalescence of numerous voids formed in the recrystallized grains is responsible for fracture, while at high strain rates or low temperatures, the grains rupture mainly by splitting because of cracks formed around the inclusions.

  17. Texture development during tensile deformation in Al-Mg alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ohtani, S.; Inagaki, H. [Shonan Inst. of Tech., Fujisawashi (Japan)

    2002-07-01

    Tensile tests were made on commercial A1050 pure Al, A5182 Al-4.4% Mg alloy and A2017 Al-4% Cu alloy by varying the test temperature and the strain rate. Textures developed at various stages of the tensile deformation were investigated with the orientation distribution function analysis. It was found that, during the tensile test of the 1050 pure Al with the strain rate of 3 x 10{sup -4}S{sup -1} at 20 C, tensile axis readily rotated toward left angle 111 right angle stable end orientation. However, such rotation occurred only at the latest stage of the tensile deformation near the ultimate tensile stress, where stress strain curve was almost flattened and work hardening was almost saturated. It was strongly suggested that, since fine and complex dislocation cell structures were developed in such a work-hardened state, smooth and long range dislocation glide such as assumed in the classical Taylor theory would not be possible. To explain the observed texture development, cooperative movement of the dislocations in the cell walls might be necessary. In fact, addition of Mg and Cu, which suppressed strongly the development of well defined cell structures due to P-L effect or dynamic strain ageing, significantly retarded the rotation of tensile axes toward left angle 111 right angle. Interesting enough, textures developed in all these materials investigated were not affected by the strain rate and the temperature of the tensile test. (orig.)

  18. Influence of relative humidity on tensile and compressive creep of ...

    African Journals Online (AJOL)

    This paper presents an experimental study on the influence of ambient relative humidity on tensile creep of plain concrete amended with Ground Granulated Blast - furnace Slag and compares it with its influence on compressive creep. Tensile and compressive creep tests were carried out on concrete specimens of 34.49 ...

  19. Mechanical properties of Zr-2.5Nb pressure tube material manufactured employing forging routes for PHWR700 - Part 1: tensile behavior

    International Nuclear Information System (INIS)

    Bind, A.K.; Singh, R.N.; Sunil, Saurav; Chakravartty, J.K.; Ghosh, Agnish; Dhandharia, Priyesh; More, Nitin S.; Vijayakumar, S.; Chhatre, A.G.

    2012-01-01

    Tensile properties of Zr-2.5Nb alloy tubes produced employing forging to break the cast structure were evaluated by carrying out uni-axial tension test at temperatures between 25 and 325 degC and under strain-rate of 1.075 x 10 -4 /s for both longitudinal and transverse specimens. Both strength and elongation values were comparable for the samples obtained from front and back end of the tube. Transverse samples showed higher strength and lower uniform elongation values as compared to longitudinal samples. The yield strength of double forged material at 25 degC is higher than the PHWR700 specification of a maximum value of 586 MPa. (author)

  20. Analysis of electromagnetic scattering by uniaxial anisotropic bispheres.

    Science.gov (United States)

    Li, Zheng-Jun; Wu, Zhen-Sen; Li, Hai-Ying

    2011-02-01

    Based on the generalized multiparticle Mie theory and the Fourier transformation approach, electromagnetic (EM) scattering of two interacting homogeneous uniaxial anisotropic spheres with parallel primary optical axes is investigated. By introducing the Fourier transformation, the EM fields in the uniaxial anisotropic spheres are expanded in terms of the spherical vector wave functions. The interactive scattering coefficients and the expansion coefficients of the internal fields are derived through the continuous boundary conditions on which the interaction of the bispheres is considered. Some selected calculations on the effects of the size parameter, the uniaxial anisotropic absorbing dielectric, and the sphere separation distance are described. The backward radar cross section of two uniaxial anisotropic spheres with a complex permittivity tensor changing with the sphere separation distance is numerically studied. The authors are hopeful that the work in this paper will help provide an effective calibration for further research on the scattering characteristic of an aggregate of anisotropic spheres or other shaped anisotropic particles.

  1. Uniaxial creep behavior of V-4Cr-4Ti alloy

    International Nuclear Information System (INIS)

    Natesan, K.; Soppet, W.K.; Purohit, A.

    2002-01-01

    We are undertaking a systematic study at Argonne National Laboratory to evaluate the uniaxial creep behavior of V-Cr-Ti alloys in a vacuum environment as a function of temperature in the range of 650-800 deg. C and at applied stress levels of 75-380 MPa. Creep strain in the specimens is measured by a linear-variable-differential transducer, which is attached between the fixed and movable pull rods of the creep assembly. Strain is measured at sufficiently frequent intervals during testing to define the creep strain/time curve. A linear least-squares analysis function is used to ensure consistent extraction of minimum creep rate, onset of tertiary creep and creep strain at the onset of tertiary creep. Creep test data, obtained at 650, 700, 725 and 800 deg. C, showed power-law creep behavior. Extensive analysis of the tested specimens is conducted to establish hardness profiles, oxygen content and microstructural characteristics. The data are also quantified by the Larson-Miller approach, and correlations are developed to relate time to rupture, onset of tertiary creep, times for 1% and 2% strain, exposure temperature and applied stress

  2. Influence of alkali-silica reaction and crack orientation on the uniaxial compressive strength of concrete cores from slab bridges

    DEFF Research Database (Denmark)

    Antonio Barbosa, Ricardo; Gustenhoff Hansen, Søren; Hansen, Kurt Kielsgaard

    2018-01-01

    ASR-damaged flat slab bridges in service. Furthermore, the influence of the ASR-induced crack orientation on the compressive strength and the Young’s modulus is investigated. Uniaxial compression tests, visual observations, and thin section examinations were performed on more than 100 cores drilled...... from the three severely ASR-damaged flat slab bridges. It was found that the orientation of ASR-induced cracks has a significant influence on the uniaxial compressive strength and the stress-strain relationship of the tested cores. The compressive strength in a direction parallel to ASR cracks can...

  3. Nonlinear and anisotropic tensile properties of graft materials used in soft tissue applications.

    Science.gov (United States)

    Yoder, Jonathon H; Elliott, Dawn M

    2010-05-01

    The mechanical properties of extracellular matrix grafts that are intended to augment or replace soft tissues should be comparable to the native tissue. Such grafts are often used in fiber-reinforced tissue applications that undergo multi-axial loading and therefore knowledge of the anisotropic and nonlinear properties are needed, including the moduli and Poisson's ratio in two orthogonal directions within the plane of the graft. The objective of this study was to measure the tensile mechanical properties of several marketed grafts: Alloderm, Restore, CuffPatch, and OrthADAPT. The degree of anisotropy and non-linearity within each graft was evaluated from uniaxial tensile tests and compared to their native tissue. The Alloderm graft was anisotropic in both the toe- and linear-region of the stress-strain response, was highly nonlinear, and generally had low properties. The Restore and CuffPatch grafts had similar stress-strain responses, were largely isotropic, had a linear-region modulus of 18MPa, and were nonlinear. OrthADAPT was anisotropic in the linear-region (131 MPA vs 47MPa in the toe-region) and was highly nonlinear. The Poisson ratio for all grafts was between 0.4 and 0.7, except for the parallel orientation of Restore which was greater than 1.0. Having an informed understanding of how the available grafts perform mechanically will allow for better assessment by the physician for which graft to apply depending upon its application. Copyright 2010 Elsevier Ltd. All rights reserved.

  4. Multi-purpose fatigue sensor. Part 1. Uniaxial and multiaxial fatigue

    Directory of Open Access Journals (Sweden)

    M.V. Karuskevich

    2016-10-01

    Full Text Available The paper describes the key principles and results of preliminary experiments aimed at the development of new technique for the fatigue life prediction under conditions of biaxial cyclic tension. The foundations of the method were developed early by the numerous tests with monitoring the process of surface deformation relief formation, which is proved to be an indicator of accumulated fatigue damage under uniaxial fatigue. The employed phenomenon was early applied for the development of a family of uniaxial loading fatigue sensors. The formation of strain induced relief has been recently taken into consideration as a part of damage accumulation criteria under biaxial fatigue as well. The home-made testing machine has been designed to implement combined bending and torsion loading that simulates loads experienced by an aircraft wing skin. The experimental evidences on formation and evolution of the deformation relief revealed under conditions of combined loading, supports the proposed concept of biaxial fatigue sensor

  5. Theoretical investigations into the influence of the position of a breaking line on the tensile failure of flat, round, bevel-edged tablets using finite element methodology (FEM) and its practical relevance for industrial tablet strength testing.

    Science.gov (United States)

    Podczeck, Fridrun; Newton, J Michael; Fromme, Paul

    2014-12-30

    Flat, round tablets may have a breaking ("score") line. Pharmacopoeial tablet breaking load tests are diametral in their design, and industrially used breaking load testers often have automatic tablet feeding systems, which position the tablets between the loading platens of the machine with the breaking lines in random orientation to the applied load. The aim of this work was to ascertain the influence of the position of the breaking line in a diametral compression test using finite element methodology (FEM) and to compare the theoretical results with practical findings using commercially produced bevel-edged, scored tablets. Breaking line test positions at an angle of 0°, 22.5°, 45°, 67.5° and 90° relative to the loading plane were studied. FEM results obtained for fully elastic and elasto-plastic tablets were fairly similar, but they highlighted large differences in stress distributions depending on the position of the breaking line. The stress values at failure were predicted to be similar for tablets tested at an angle of 45° or above, whereas at lower test angles the predicted breaking loads were up to three times larger. The stress distributions suggested that not all breaking line angles would result in clean tensile failure. Practical results, however, did not confirm the differences in the predicted breaking loads, but they confirmed differences in the way tablets broke. The results suggest that it is not advisable to convert breaking loads obtained on scored tablets into tablet tensile strength values, and comparisons between different tablets or batches should carefully consider the orientation of the breaking line with respect to the loading plane, as the failure mechanisms appear to vary. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Investigation of the Microstructure Evolution in a Fe-17Mn-1.5Al-0.3C Steel via In Situ Synchrotron X-ray Diffraction during a Tensile Test.

    Science.gov (United States)

    Ma, Yan; Song, Wenwen; Bleck, Wolfgang

    2017-09-25

    The quantitative characterization of the microstructure evolution in high-Mn steel during deformation is of great importance to understanding its strain-hardening behavior. In the current study, in situ high-energy synchrotron X-ray diffraction was employed to characterize the microstructure evolution in a Fe-17Mn-1.5Al-0.3C steel during a tensile test. The microstructure at different engineering strain levels-in terms of ε-martensite and α'-martensite volume fractions, the stacking fault probability, and the twin fault probability-was analyzed by the Rietveld refinement method. The Fe-17Mn-1.5Al-0.3C steel exhibits a high ultimate tensile strength with a superior uniform elongation and a high strain-hardening rate. The remaining high strain-hardening rate at the strain level about 0.025 to 0.35 results from ε-martensite dominant transformation-induced-plasticity (TRIP) effect. The increase in the strain-hardening rate at the strain level around 0.35 to 0.43 is attributed to the synergetic α'-martensite dominant TRIP and twinning-induced-plasticity (TWIP) effects. An evaluation of the stacking fault energy (SFE) of the Fe-17Mn-1.5Al-0.3C steel by the synchrotron measurements shows good agreement with the thermodynamic calculation of the SFE.

  7. Strain and texture evolution of ED-rotated cubes during quasi-static and dynamic tensile testing of Al-Mg-Si-profiles in the as-extruded T1-temper condition

    International Nuclear Information System (INIS)

    Mathiesen, R.H.; Forbord, B.; Mardalen, J.; Furu, T.; Lange, H.I.

    2007-01-01

    High-energy synchrotron X-ray diffraction has been used to study through-thickness deformation response in extruded Al-Mg-Si-profiles during tensile testing, in terms of micro- and mesoscopic distributions and dynamical evolution of elastic strains and grain rotations. Local averaging with analysis at intermediate length scales reveals strongly inhomogeneous through-profile elastic strains, caused by the presence of three distinct microstructure regions and the compatibility relations that apply at their interfaces. Variations in elastic strains at characteristic microstructure lengths are found to be large; typically 1σ Gaussian spreads for the different ε ij -components of the elastic strain tensor are minimal and of the order 1.0 x 10 -3 in the central profile region at low stresses. The spread increases with the tensile loads, but even more dramatically with decreasing distance to the surfaces where maximum 1σ spreads up to 6-7 x 10 -3 are encountered. The evolution and distribution of certain texture components have been analysed, showing grain rotations to be a non-negligible part of the deformation response that activates at quite modest plastic deformations. Inhomogeneous strain response at local and intermediate length scales together with the strain and texture component relations that apply across the microstructure region boundaries are found to be decisive to surface roughening. All together, the results point in the direction that strain and texture evolution should be considered together in order to provide a more complete description of microstructure mechanics in metals

  8. Analysis of tensile strain enhancement in Ge nano-belts on an insulator surrounded by dielectrics

    International Nuclear Information System (INIS)

    Lu Wei-Fang; Li Cheng; Huang Shi-Hao; Lin Guang-Yang; Wang Chen; Yan Guang-Ming; Huang Wei; Lai Hong-Kai; Chen Song-Yan

    2013-01-01

    Ge nano-belts with large tensile strain are considered as one of the promising materials for high carrier mobility metal—oxide—semiconductor transistors and efficient photonic devices. In this paper, we design the Ge nano-belts on an insulator surrounded by Si 3 N 4 or SiO 2 for improving their tensile strain and simulate the strain profiles by using the finite difference time domain (FDTD) method. The width and thickness parameters of Ge nano-belts on an insulator, which have great effects on the strain profile, are optimized. A large uniaxial tensile strain of 1.16% in 50-nm width and 12-nm thickness Ge nano-belts with the sidewalls protected by Si 3 N 4 is achieved after thermal treatments, which would significantly tailor the band gap structures of Ge-nanobelts to realize the high performance devices. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  9. Band structure of Si/Ge core-shell nanowires along the [110] direction modulated by external uniaxial strain

    International Nuclear Information System (INIS)

    Peng Xihong; Tang Fu; Logan, Paul

    2011-01-01

    Strain modulated electronic properties of Si/Ge core-shell nanowires along the [110] direction were reported, on the basis of first principles density-functional theory calculations. In particular, the energy dispersion relationship of the conduction/valence band was explored in detail. At the Γ point, the energy levels of both bands are significantly altered by applied uniaxial strain, which results in an evident change of the band gap. In contrast, for the K vectors far away from Γ, the variation of the conduction/valence band with strain is much reduced. In addition, with a sufficient tensile strain (∼1%), the valence band edge shifts away from Γ, which indicates that the band gap of the Si/Ge core-shell nanowires experiences a transition from direct to indirect. Our studies further showed that effective masses of charge carriers can also be tuned using the external uniaxial strain. The effective mass of the hole increases dramatically with tensile strain, while strain shows a minimal effect on tuning the effective mass of the electron. Finally, the relation between strain and the conduction/valence band edge is discussed thoroughly in terms of site-projected wavefunction characters.

  10. Irradiation testing of stainless steel plate material and weldments. Report on ITER Task T14, Part B. Tensile properties after 0.5 and 5 dpa at 350 and 500 K

    International Nuclear Information System (INIS)

    Rensman, J.W.; Boskeljon, J.; Horsten, M.G.; De Vries, M.I.

    1997-10-01

    The tensile properties of unirradiated and neutron irradiated type 316L(N)-SPH stainless steel plate, EB weldments, 16-8 TIG-weldments, and full 16-8 TIG-deposits have been measured. Miniature 4 mm diameter test specimens of the European Reference Heat 1 and 2 (ERH), and 4 mm and some 8 mm diameter specimens of the weldments mentioned above, were irradiated in the High Flux Reactor (HFR) in Petten, The Netherlands, simulating the first wall conditions by a combination of high displacement damage with high amounts of helium. The irradiation conditions were 0.5 and 5 displacements per atom (dpa) at 350K and 0.5 and 5 dpa at 500K. Testing temperatures ranged from 300K to 850K. This work was performed as part of the European Fusion Technology Programme for ITER as 'Irradiation testing of stainless steel' The report contains the experimental conditions and summarises the results. The tensile properties of the unirradiated ERH's 1 and 2 plate materials were found to differ slightly but significantly: ERH2 has a lower UTS, but higher yield strength and ductility than ERH1. The plate materials have lower yield strength in the unirradiated condition than all of the weldments (EB, TIG-weld and TIG-deposit), accompanied by a higher ductility of the plate materials. When irradiated at 350K the differences in strength between the plate and weld materials decrease, but the ductility of the plate remains higher than that of the weldments. A saturation of irradiation damage has taken place already at about 0.5 dpa. When irradiated at 500K the plate material continuously hardens up to 5 dpa, where it has lost all uniform plastic ductility. The weldments show similar but less dramatic hardening and loss of ductility as the plate material for both irradiation conditions. 54 figs., 17 tabs., 21 refs

  11. Fracture behavior of nuclear graphites under tensile impact loading

    International Nuclear Information System (INIS)

    Ugachi, Hirokazu; Ishiyama, Shintaro; Eto, Motokuni

    1994-01-01

    Impact tensile strength test was performed with two kinds of HTTR graphites, fine grained isotropic graphite, IG-11 and coarse grained near isotropic graphite, PGX and deformation and fracture behavior under the strain rate of over 100s -1 was measured and the following results were derived: (1) Tensile strength for IG-11 graphite does not depend on the strain rate less than 1 s -1 , but over 1 s -1 , tensile strength for IG-11 graphite increase larger than that measured under 1 s -1 . At the strain rate more than 100 s -1 , remarkable decrease of tensile strength for IG-11 graphite was found. Tensile strength of PGX graphite does not depend on the strain rate less than 1 s -1 , but beyond this value, the sharp tensile strength decrease occurs. (2) Under 100 s -1 , fracture strain for both graphites increase with increase of strain rate and over 100 s -1 , drastic increase of fracture strain for IG-11 graphite was found. (3) At the part of gage length, volume of specimen increase with increase of tensile loading level and strain rate. (4) Poisson's ratio for both graphites decrease with increase of tensile loading level and strain rate. (5) Remarkable change of stress-strain curve for both graphites under 100 s -1 was not found, but over 100 s -1 , the slope of these curve for IG-11 graphite decrease drastically. (author)

  12. Coarse-grained molecular dynamics simulations of the tensile behavior of a thermosetting polymer

    Science.gov (United States)

    Yang, Shaorui; Qu, Jianmin

    2014-07-01

    Using a previously developed coarse-grained model, we conducted large-scale (˜85×85×85nm3) molecular dynamics simulations of uniaxial-strain deformation to study the tensile behavior of an epoxy molding compound, epoxy phenol novolacs (EPN) bisphenol A (BPA). Under the uniaxial-strain deformation, the material is found to exhibit cavity nucleation and growth, followed by stretching of the ligaments separated by the cavities, until the ultimate failure through ligament scissions. The nucleation sites of cavities are rather random and the subsequent cavity growth accounts for much (87%) of the volumetric change during the uniaxial-strain deformation. Ultimate failure of the materials occurs when the cavity volume fraction reaches ˜60%. During the entire deformation process, polymer strands in the network are continuously extended to their linear states and broken in the postyielding strain hardening stage. When most of the strands are stretched to their taut configurations, rapid scission of a large number of strands occurs within a small strain increment, which eventually leads to fracture. Finally, through extensive numerical simulations of various loading conditions in addition to uniaxial strain, we find that yielding of the EPN-BPA can be described by the pressure-modified von Mises yield criterion.

  13. Coarse-grained molecular dynamics simulations of the tensile behavior of a thermosetting polymer.

    Science.gov (United States)

    Yang, Shaorui; Qu, Jianmin

    2014-07-01

    Using a previously developed coarse-grained model, we conducted large-scale (∼ 85 × 85 × 85 nm(3)) molecular dynamics simulations of uniaxial-strain deformation to study the tensile behavior of an epoxy molding compound, epoxy phenol novolacs (EPN) bisphenol A (BPA). Under the uniaxial-strain deformation, the material is found to exhibit cavity nucleation and growth, followed by stretching of the ligaments separated by the cavities, until the ultimate failure through ligament scissions. The nucleation sites of cavities are rather random and the subsequent cavity growth accounts for much (87%) of the volumetric change during the uniaxial-strain deformation. Ultimate failure of the materials occurs when the cavity volume fraction reaches ∼ 60%. During the entire deformation process, polymer strands in the network are continuously extended to their linear states and broken in the postyielding strain hardening stage. When most of the strands are stretched to their taut configurations, rapid scission of a large number of strands occurs within a small strain increment, which eventually leads to fracture. Finally, through extensive numerical simulations of various loading conditions in addition to uniaxial strain, we find that yielding of the EPN-BPA can be described by the pressure-modified von Mises yield criterion.

  14. Failure Mechanisms of Brittle Rocks under Uniaxial Compression

    Science.gov (United States)

    Liu, Taoying; Cao, Ping

    2017-09-01

    The behaviour of a rock mass is determined not only by the properties of the rock matrix, but mostly by the presence and properties of discontinuities or fractures within the mass. The compression test on rock-like specimens with two prefabricated transfixion fissures, made by pulling out the embedded metal inserts in the pre-cured period was carried out on the servo control uniaxial loading tester. The influence of the geometry of pre-existing cracks on the cracking processes was analysed with reference to the experimental observation of crack initiation and propagation from pre-existing flaws. Based on the rock fracture mechanics and the stress-strain curves, the evolution failure mechanism of the fissure body was also analyzed on the basis of exploring the law of the compression-shear crack initiation, wing crack growth and rock bridge connection. Meanwhile, damage fracture mechanical models of a compression-shear rock mass are established when the rock bridge axial transfixion failure, tension-shear combined failure, or wing crack shear connection failure occurs on the specimen under axial compression. This research was of significance in studying the failure mechanism of fractured rock mass.

  15. Tensile properties of polymethyl methacrylate coated natural fabric Sterculia urens

    CSIR Research Space (South Africa)

    Jayaramudu, J

    2009-04-01

    Full Text Available stress, Young's modulus and % elongation at break were determined using a Universal Testing Machine. The effect of alkali treatment and the polymethyl methacrylate coating on tensile properties of the fabric was studied. The morphology of the fabric...

  16. Ultrasound transmission measurements for tensile strength evaluation of tablets.

    Science.gov (United States)

    Simonaho, Simo-Pekka; Takala, T Aleksi; Kuosmanen, Marko; Ketolainen, Jarkko

    2011-05-16

    Ultrasound transmission measurements were performed to evaluate the tensile strength of tablets. Tablets consisting of one ingredient were compressed from dibasic calcium phosphate dehydrate, two grades of microcrystalline cellulose and two grades of lactose monohydrate powders. From each powder, tablets with five different tensile strengths were directly compressed. Ultrasound transmission measurements were conducted on every tablet at frequencies of 2.25 MHz, 5 MHz and 10 MHz and the speed of sound was calculated from the acquired waveforms. The tensile strength of the tablets was determined using a diametrical mechanical testing machine and compared to the calculated speed of sound values. It was found that the speed of sound increased with the tensile strength for the tested excipients. There was a good correlation between the speed of sound and tensile strength. Moreover, based on the statistical tests, the groups with different tensile strengths can be differentiated from each other by measuring the speed of sound. Thus, the ultrasound transmission measurement technique is a potentially useful method for non-destructive and fast evaluation of the tensile strength of tablets. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Effect of tensile stress on cavitation damage formation in mercury

    Energy Technology Data Exchange (ETDEWEB)

    Naoe, Takashi, E-mail: naoe.takashi@jaea.go.j [J-PARC Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kogawa, Hiroyuki [J-PARC Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Yamaguchi, Yoshihito [Nuclear Safety Research Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Futakawa, Masatoshi [J-PARC Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan)

    2010-03-15

    Cavitation erosion or so called pitting damage was investigated under tensile stress conditions in mercury. In MW-class liquid metal spallation targets, pitting damage is a critical issue to satisfy required power and/or lifetime of the target vessel. Cavitation occurs by negative pressure which is induced through pressure wave propagation due to proton beam injection. Pitting damage is formed by microjet and/or shock wave during cavitation bubble collapse. A mercury target vessel suffers tensile stress due to thermal stress or welding. In order to investigate the effect of tensile stress on pitting damage formation, cavitation erosion tests were performed using stress imposed specimens in mercury. An ultrasonic vibratory horn and electro-Magnetic IMpact Testing Machine (MIMTM) were used to vary the cavitation intensity. In the incubation period of pitting damage, damaged area was slightly increased with increasing imposed tensile stress. In the steady state period, a mean depth of erosion was increased by the tensile stress. Additionally, in order to quantitatively evaluate the effect of tensile stress, an indentation test with Vickers indenter was carried out to quasi-statically simulate the impact load. From the measurement of the diagonal length of the indent aspect ratio and hardness, it is recognized that the threshold of the deformation, i.e. pitting damage formation, was decreased by the tensile stress.

  18. Cavitation erosion tests of high tensile stainless steels for the Techno-Superliner (TSL-F) hulls; Techno superliner (TSL-F) sentai kozoyo kokyodo stainless ko no cavitation erosion

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, M.; Ito, H.; Shibasaki, K. [NKK Corp., Tokyo (Japan); Mizuta, A.; Sugimoto, H. [Kawasaki Heavy Industries, Ltd., Kobe (Japan); Tomono, Y. [Hitachi Zosen Corp., Osaka (Japan)

    1996-12-31

    Investigations were given by using the magnetostrictive vibration method and the high-speed fluid testing method on cavitation erosion resistance of high-tensile stainless steels thought to have high applicability to submerged hull structures of Techno-Supeliner (TSL-L). The investigations revealed that these steels have nearly equivalent resistance to even SUS 304 or 15-5PH steel which is thought to have the highest cavitation erosion resistance among the conventional materials used customarily. An experiment using both materials provided a result different quantitatively but similar qualitatively in relative merits between the materials. Correlation between both materials was presented. A cavitation erosion experiment using a 1/6 scale model of the actual TSL-F was carried out to measure the amount of cavitation erosion generated on wing surfaces. Results from the experiment were used to attempt estimation of cavitation erosion amount at the level of the actual TSL-F. 21 refs., 12 figs., 3 tabs.

  19. Experimental study on the usefulness of magnetotherapy in bone fractures (tibial osteotomy in the rat). Accumulation of 99 mTc MDP - tests of tensile strength - determination of alkaline phosphatase

    International Nuclear Information System (INIS)

    Sailer, R.

    1985-01-01

    Non-directional magnetic field therapy using a flux density of 60 G and a frequency of 25 Hz was carried out over 12 hours daily in rats in order to ascertain its influence on the healing process following osteotomy of the tibia with internal splint fixation of the fractured bone being carried out as an additional measure. The results thus achieved were compared to those seen in control animals, were no magnetotherapy was carried out, on the basis of scintiscan studies using 99 mTc MDP (degree of density in the callus formed around the fracture zone), the plasma levels of alkaline phosphatase and tests of tensile strength. The follow-up observations of the healing process were additionally based on radiological and histological evaluations of the animals. Beneficial effects of magnetotherapy on the healing process could not be confirmed with any statistical significance. (TRV) [de

  20. Cavitation erosion tests of high tensile stainless steels for the Techno-Superliner (TSL-F) hulls; Techno superliner (TSL-F) sentai kozoyo kokyodo stainless ko no cavitation erosion

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, M; Ito, H; Shibasaki, K [NKK Corp., Tokyo (Japan); Mizuta, A; Sugimoto, H [Kawasaki Heavy Industries, Ltd., Kobe (Japan); Tomono, Y [Hitachi Zosen Corp., Osaka (Japan)

    1997-12-31

    Investigations were given by using the magnetostrictive vibration method and the high-speed fluid testing method on cavitation erosion resistance of high-tensile stainless steels thought to have high applicability to submerged hull structures of Techno-Supeliner (TSL-L). The investigations revealed that these steels have nearly equivalent resistance to even SUS 304 or 15-5PH steel which is thought to have the highest cavitation erosion resistance among the conventional materials used customarily. An experiment using both materials provided a result different quantitatively but similar qualitatively in relative merits between the materials. Correlation between both materials was presented. A cavitation erosion experiment using a 1/6 scale model of the actual TSL-F was carried out to measure the amount of cavitation erosion generated on wing surfaces. Results from the experiment were used to attempt estimation of cavitation erosion amount at the level of the actual TSL-F. 21 refs., 12 figs., 3 tabs.

  1. Determination of deformation and strength characteristics of artificial geomaterial having step-shaped discontinuities under uniaxial compression

    Science.gov (United States)

    Tsoy, PA

    2018-03-01

    In order to determine the empirical relationship between the linear dimensions of step-shaped macrocracks in geomaterials as well as deformation and strength characteristics of geomaterials (ultimate strength, modulus of deformation) under uniaxial compression, the artificial flat alabaster specimens with the through discontinuities have been manufactured and subjected to a series of the related physical tests.

  2. Elastic properties of uniaxial-fiber reinforced composites - General features

    Science.gov (United States)

    Datta, Subhendu; Ledbetter, Hassel; Lei, Ming

    The salient features of the elastic properties of uniaxial-fiber-reinforced composites are examined by considering the complete set of elastic constants of composites comprising isotropic uniaxial fibers in an isotropic matrix. Such materials exhibit transverse-isotropic symmetry and five independent elastic constants in Voigt notation: C(11), C(33), C(44), C(66), and C(13). These C(ij) constants are calculated over the entire fiber-volume-fraction range 0.0-1.0, using a scattered-plane-wave ensemple-average model. Some practical elastic constants such as the principal Young moduli and the principal Poisson ratios are considered, and the behavior of these constants is discussed. Also presented are the results for the four principal sound velocities used to study uniaxial-fiber-reinforced composites: v(11), v(33), v(12), and v(13).

  3. Characteristics of Crushing Energy and Fractal of Magnetite Ore under Uniaxial Compression

    Science.gov (United States)

    Gao, F.; Gan, D. Q.; Zhang, Y. B.

    2018-03-01

    The crushing mechanism of magnetite ore is a critical theoretical problem on the controlling of energy dissipation and machine crushing quality in ore material processing. Uniaxial crushing tests were carried out to research the deformation mechanism and the laws of the energy evolution, based on which the crushing mechanism of magnetite ore was explored. The compaction stage and plasticity and damage stage are two main compression deformation stages, the main transitional forms from inner damage to fracture are plastic deformation and stick-slip. In the process of crushing, plasticity and damage stage is the key link on energy absorption for that the specimen tends to saturate energy state approaching to the peak stress. The characteristics of specimen deformation and energy dissipation can synthetically reply the state of existed defects inner raw magnetite ore and the damage process during loading period. The fast releasing of elastic energy and the work done by the press machine commonly make raw magnetite ore thoroughly broken after peak stress. Magnetite ore fragments have statistical self-similarity and size threshold of fractal characteristics under uniaxial squeezing crushing. The larger ratio of releasable elastic energy and dissipation energy and the faster energy change rate is the better fractal properties and crushing quality magnetite ore has under uniaxial crushing.

  4. Discrete analysis of clay layer tensile strength

    International Nuclear Information System (INIS)

    Le, T.N.H.; Ple, O.; Villard, P.; Gourc, J.P.

    2010-01-01

    The Discrete Element Method is used to investigate the tensile behaviour and cracks mechanisms of a clay material submitted to bending loading. It is the case of compacted clay liners in landfill cap cover application. Such as the soil tested in this study is plastic clay, the distinct elements model was calibrated with previous data results by taking into account cohesive properties. Various contact and cohesion laws are tested to show that the numerical model is able to reproduce the failure mechanism. Numerical results are extending to simulate a landfill cap cover and comparing to experimental large scale field bending tests achieved in a real site of storage. (authors)

  5. Preliminary study on tensile properties and fractography of the recycled aluminum cast product

    International Nuclear Information System (INIS)

    Hishamuddin Hussain; Mohd Harun; Hafizal Yazid; Shaiful Rizam Shamsudin; Zaiton Selamat; Mohd Shariff Sattar

    2004-01-01

    Among many mechanical properties of materials, tensile properties are probably the most frequently considered, evaluated, and referred by the industry. This paper presents the result of preliminary study regarding the tensile properties and fractography of the recycled aluminum cast product. For this purpose, three sets of specimen were prepared for tensile testing by using permanent mold casting technique. The cast products are in durable shaped tensile specimens with the gauge length of 50mm. The tensile testing was conducted in accordance with BS EN 10002-1 and ISO 6892 standards. Fracture surface analysis was also conducted to understand materials behaviour. (Author)

  6. The tensile properties of single sugar palm (Arenga pinnata) fibre

    Science.gov (United States)

    Bachtiar, D.; Sapuan, S. M.; Zainudin, E. S.; Khalina, A.; Dahlan, K. Z. M.

    2010-05-01

    This paper presents a brief description and characterization of the sugar palm fibres, still rare in the scientific community, compared to other natural fibres employed in polymeric composites. Sugar palm fibres are cellulose-based fibres extracted from the Arenga pinnata plant. The characterization consists of tensile test and the morphological examination. The average tensile properties results of fibres such as Young's modulus is equal to 3.69 GPa, tensile strength is equal to 190.29 MPa, and strain at failure is equal to 19.6%.

  7. The tensile properties of single sugar palm (Arenga pinnata) fibre

    International Nuclear Information System (INIS)

    Bachtiar, D; Sapuan, S M; Zainudin, E S; Khalina, A; Dahlan, K Z M

    2010-01-01

    This paper presents a brief description and characterization of the sugar palm fibres, still rare in the scientific community, compared to other natural fibres employed in polymeric composites. Sugar palm fibres are cellulose-based fibres extracted from the Arenga pinnata plant. The characterization consists of tensile test and the morphological examination. The average tensile properties results of fibres such as Young's modulus is equal to 3.69 GPa, tensile strength is equal to 190.29 MPa, and strain at failure is equal to 19.6%.

  8. Sample damage investigation by laboratory testing and DDM modelling by FRACOD2D of Brazilian tests on Toki granite

    International Nuclear Information System (INIS)

    Lanaro, Flavio; Sato, Toshinori; Funato, Akio

    2008-01-01

    Numerical scooping calculations by means of FRACOD 2D had shown that Brazilian test models present a bend in the relation between the sample deformation perpendicularly to the loading direction and the load itself. The input 'direct' tensile strength of the rock could be re-obtained based on the numerical load at the bend. In this study, a similar technique is applied to specially designed Brazilian tests on Toki granite (Gifu, Japan) which also exhibits such bend for a tensile stress in the centre of the samples of about 2.6 MPa. However, the samples show a wide range of Brazilian tensile strengths that appear to be negatively correlated to the level of in-situ stress at the depth where the samples were taken. The correlation was interpreted as an effect of sample damage due to drilling in a stressed rock mass. Numerical models were designed with various preexist ent crack patterns to simulate the sample damage. The numerical results show Brazilian peak strength results ranging between 6.7 and 13.0 MPa, which are very realistic considering that the laboratory Brazilian tensile strength was observed to vary between 4.1 and 11.3 MPa. These values are all larger than the stress at the bend which is then interpreted as the tensile strength of the weakest grains in the granite. It is also shown that the occurrence of newly initiated cracks at the bend completely changes the stress distribution and failure mechanism of the samples: this explains why the Brazilian tensile strength should be higher than the 'direct' tensile strength of the rock from uniaxial tests. (author)

  9. Switching the uniaxial magnetic anisotropy by ion irradiation induced compensation

    Science.gov (United States)

    Yuan, Ye; Amarouche, Teyri; Xu, Chi; Rushforth, Andrew; Böttger, Roman; Edmonds, Kevin; Campion, Richard; Gallagher, Bryan; Helm, Manfred; Jürgen von Bardeleben, Hans; Zhou, Shengqiang

    2018-04-01

    In the present work, the uniaxial magnetic anisotropy of GaMnAsP is modified by helium ion irradiation. According to the micro-magnetic parameters, e.g. resonance fields and anisotropy constants deduced from ferromagnetic resonance measurements, a rotation of the magnetic easy axis from out-of-plane [0 0 1] to in-plane [1 0 0] direction is achieved. From the application point of view, our work presents a novel avenue in modifying the uniaxial magnetic anisotropy in GaMnAsP with the possibility of lateral patterning by using lithography or focused ion beam.

  10. Dynamic Uniaxial Compression of HSLA-65 Steel at Elevated Temperatures

    Science.gov (United States)

    Dike, Shweta; Wang, Tianxue; Zuanetti, Bryan; Prakash, Vikas

    2017-12-01

    In the present study, the dynamic response of a high-strength, low alloy Grade 65 (HSLA-65) steel, used by the United States Navy for ship hull construction, is investigated under dynamic uniaxial compression at temperatures ranging from room temperature to 1000 °C using a novel elevated temperature split-Hopkinson pressure bar. These experiments are designed to probe the dynamic response of HSLA-65 steel in its single α-ferrite phase, mixed α + γ-austenite phase, and the single γ-austenite phase, as a function of temperature. The investigation is conducted at two different average strain rates—1450 and 2100/s. The experimental results indicate that at test temperatures in the range from room temperature to lower than 600 °C, i.e. prior to the development of the mixed α + γ phase, a net softening in flow strength is observed at all levels of plastic strain with increase in test temperatures. As the test temperatures are increased, the rate of this strain softening with temperature is observed to decrease, and at 600 °C the trend reverses itself resulting in an increase in flow stress at all strains tested. This increase in flow stress is understood be due to dynamic strain aging, where solute atoms play a distinctive role in hindering dislocation motion. At 800 °C, a (sharp) drop in the flow stress, equivalent to one-half of its value at room temperature, is observed. As the test temperature are increased to 900 and 1000 °C, further drop in flow stress are observed at all plastic strain levels. In addition, strain hardening in flow stress is observed at all test temperatures up to 600 °C; beyond 800 °C the rate of strain hardening is observed to decrease, with strain softening becoming dominant at temperatures of 900 °C and higher. Moreover, comparing the high strain rate stress versus strain data gathered on HSLA 65 in the current investigation with those available in the literature at quasi-static strain rates, strain-rate hardening can be

  11. Tensile behavior of borated stainless steels

    International Nuclear Information System (INIS)

    Stephens, J.J. Jr.; Sorenson, K.B.

    1991-01-01

    Borated stainless steel tensile testing is being conducted at Sandia National Laboratories (SNL). The goal of the test program is to provide data to support a code case inquiry to the ASME Boiler and Pressure Vessel Code, Section III. The adoption by ASME facilitates a material's qualification for structural use in transport cask applications. For transport cask basket applications, the potential advantage to using borated stainless steel arises from the fact that the structural and criticality control functions can be combined into one material. This can result in a decrease in net section thickness of the basket web (increased payload capacity) and eliminates the fabrication process and cost of attaching a discrete boron poison material to the basket web. In addition, adding borate stainless steel to the inventory of acceptable structural material provides the Department of Energy (DOE) and its cask contractors an alternative to current proposed materials which have not been qualified for structural service. The test program at SNL involves procuring material, machining test specimens, and conducting the tensile tests. From test measurements obtained so far, general trends indicate that tensile properties (yield strength and ultimate strength) increase with boron content and are in all cases superior to the minimum required properties established in A-240, Type 304, a typical grade of austenitic stainless steel. Therefore, in a designed basket, web thicknesses using borated stainless steel would be comparable to or thinner tan an equivalent basket manufactured from a typical stainless steel without boron additions. General trends from test results indicate that ductilities decrease with increasing boron content

  12. Study on elastic-plastic behaviour of inclusions in cold drawn wire by using reverse analysis and nanoindentation test

    Directory of Open Access Journals (Sweden)

    Lee Kyung-Hun

    2015-01-01

    Full Text Available The purpose of this study is to investigate the elastic-plastic behavior of inclusions, i.e. SiO2 particles, in cold drawn wire using reverse analysis and nanoindentation test. First, the nanoindentation tests were performed to obtain indentation load P – penetration depth h curves. Second, the reverse analysis which is consisted of various dimensionless functions including change in E∗/σr, Wp/Wt and n was used to extract the elastic-plastic properties of the indented inclusions and metals from indentation responses. To verify the accuracy of calculated properties, uniaxial tensile tests were performed for different materials which are AISI 1045 and AISI 1080. Results (E, σy, n of tensile tests for each material were also compared with those of nanoindentation tests.

  13. Two new tensile devices for X-ray diffraction experiments

    International Nuclear Information System (INIS)

    Freri, N.; Tintori, A.; Depero, L.E.; Sangaletti, L.; Cernuschi, F.; Ghia, S.

    1995-12-01

    Two tensile devices were designed to be used with parallel beam and parafocusing-geometry diffractometers. In the first case the device was designed to be attached to a strainflex diffractometer by Rigaku Inc., dedicated to stress analysis and commonly used in metallurgical industry. Since the sample does not move during the measurement, the tensile device can be kept fixed on the experimental table. The device design takes into account the steric hindrance by moving parts of diffractometer. The maximun load that can be applied to the sample is 60.000 N. An attachement to a Siemens D5000 diffractometer with Eulerian cradle has also benn designed for applying a load up tp 6000 N to a sample in the parafocusing-geometry. The installation does not require a re-alignment of the diffractometer. In both cases strain gages were applied to both sides of the specimen for the simultaneous determination of the macroscopic strains. Experiments based on the use of these devices are planned to determine the crystallographic elastic constants and study the influence of the microstructure on the mechanical behaviour of residual stresses in the zone of almost static stresses as well as the influence of residual stresses on uniaxially loaded samples. In addition, by using these devices, it is possible to measure the unstressed d-0 spacings providing useful information in the neutron diffraction study fo stress fields in steel samples

  14. Two new tensile devices for X-ray diffraction experiments

    Energy Technology Data Exchange (ETDEWEB)

    Freri, N.; Tintori, A.; Depero, L.E.; Sangaletti, L. [Brescia Univ. (Italy); Cernuschi, F.; Ghia, S. [Ente Nazionale per l`Energia Elettrica, Milan (Italy)

    1995-12-01

    Two tensile devices were designed to be used with parallel beam and parafocusing-geometry diffractometers. In thefirst case the device was designed to be attached to a strainflex diffractometer by Rigaku Inc., dedicated to stress analysis and commonly used in metallurgical industry. Since the sample does not move during the measurement, the tensile device can be kept fixed on the experimental table. The device design takes into account the steric hindrance by moving parts of diffractometer. The maximun load that can be applied to the sample is 60.000 N. An attachement to a Siemens D5000 diffractometer with Eulerian cradle has also benn designed for applying a load up tp 6000 N to a sample in the parafocusing-geometry. The installation does not require a re-alignment of the diffractometer. In both cases strain gages were applied to both sides of the specimen for the simultaneous determination of the macroscopic strains. Experiments based on the use of these devices are planned to determine the crystallographic elastic constants and study the influence of the microstructure on the mechanical behaviour of residual stresses in the zone of almost static stresses as well as the influence of residual stresses on uniaxially loaded samples. In addition, by using these devices, it is possible to measure the unstressed d-0 spacings providing useful information in the neutron diffraction study fo stress fields in steel samples.

  15. Laboratory testing of gneissic rocks in Olkiluoto borehole OL-KR24

    International Nuclear Information System (INIS)

    Eloranta, P.

    2006-10-01

    The stress-strain behaviour of anisotropic gneissic rocks from Olkiluoto, Finland, was studied for a total of 25 rock mechanics tests. Samples were selected from borehole OLKR24 at a depth level of 417-442 m. Tests included 15 uniaxial compression tests, 10 indirect tensile strength tests and 6 triaxial compression tests. Strain gauges were installed in five samples to evaluate the anisotropic properties, and acoustic emission sensors were installed in ten samples to estimate the stress damage levels. The specimen preparation and tests were carried out at the Laboratory of Rock Engineering, Helsinki University of Technology, Finland. Specimens were tested under laboratory-air-dry conditions and were photographed before and after the tests. The values obtained for the uniaxial compressive strength were in the range 56.5 - 165.9 MPa and for the indirect tensile strength 7.7 - 12.1 MPa. The anisotropic ratio of Young's modulus, E/E', was of the order of 1.1. (orig.)

  16. The prediction of creep damage in type 347 weld metal. Part I: the determination of material properties from creep and tensile tests

    International Nuclear Information System (INIS)

    Spindler, M.W.

    2005-01-01

    Calculations of creep damage under conditions of strain control are often carried out using either a time fraction approach or a ductility exhaustion approach. In the case of the time fraction approach the rupture strength is used to calculate creep damage, whereas creep ductility is used in the ductility exhaustion approach. In part I of this paper the methods that are used to determine these material properties are applied to some creep and constant strain rate tests on a Type 347 weld metal. In addition, new developments to the ductility exhaustion approach are described which give improved predictions of creep damage at failure in these tests. These developments use reverse modelling to determine the most appropriate creep damage model as a function of strain rate, stress and temperature. Hence, the new approach is no longer a ductility exhaustion approach but is a true creep damage model

  17. Evaluation of tensile strength of tissue adhesives and sutures for clear corneal incisions using porcine and bovine eyes, with a novel standardized testing platform

    Directory of Open Access Journals (Sweden)

    Kaja S

    2012-02-01

    Full Text Available Simon Kaja, Daryl L Goad, Fatima Ali, Ashley Abraham, R Luke Rebenitsch, Savak Teymoorian, Rohit Krishna, Peter KoulenVision Research Center and Department of Ophthalmology, University of Missouri-Kansas City, School of Medicine, Kansas City, MO, USABackground: Tissue adhesives for ophthalmologic applications were proposed almost 50 years ago, yet to date no adequate tissue glues have been identified that combine strong sealing properties with adequate safety and absence of postsurgical side effects. In recent years, cataract surgeries and Descemet's stripping with endothelial keratoplasty procedures have significantly increased the number of clear corneal incisions performed. One of the obstacles to discovery and development of novel tissue adhesives has been the result of nonstandardized testing of potential tissue glues.Methods: We developed an instrument capable of controlling intraocular pressure in explanted porcine and bovine eyes in order to evaluate sealants, adhesives, and surgical closure methods used in ophthalmic surgery in a controlled, repeatable, and validated fashion. We herein developed and validated our instrument by testing the adhesive properties of cyanoacrylate glue in both porcine and bovine explant eyes.Results: The instrument applied and maintained intraocular pressure through a broad range of physiological intraocular pressures. Cyanoacrylate-based glues showed significantly enhanced sealing properties of clear corneal incisions compared with sutured wounds.Conclusion: This study shows the feasibility of our instrument for reliable and standardized testing of tissue adhesive for ophthalmological surgery.Keywords: manometer, intraocular pressure, applanation tonometry, clear corneal incision, tissue adhesive, ocular surgery

  18. PDS 1-5. Divertor heat sink materials pre- and post-neutron irradiation. Tensile and fatigue tests of brazed joints of molybdenum alloys and 316L stainless steel

    International Nuclear Information System (INIS)

    Lind, Anders.

    1994-01-01

    Tensile specimens from brazed joints of molybdenum alloys (TZM or Mo-5%Re) and Type 316L austenitic stainless steel tubes have been tested at ambient temperature and 127 degrees C before and after neutron irradiation at about 40 degrees C to approximately 0.2 dpa. The unirradiated specimens showed generally ductile behaviour, but the irradiated specimens were notch sensitive and failed in a brittle manner with zero elongation; in all cases the fracture occurred in the molybdenum alloy. The brittle behaviour is consistent with previously published data and results from the increase in strength (radiation hardening) and the associated increase in the ductile-brittle transition temperature (radiation embrittlement) induced in the body-centered-cubic (BCC) molybdenum alloys by irradiation to relatively low displacement doses. The same type of irradiated specimens were also used in fatigue tests. However, the results from the fatigue tests are too limited and complementary studies are needed. During exposure to water locally up to 25% of the wall thickness of the Mo-alloys has corroded away. These observations cast serious doubts on the viability of the molybdenum alloys for divertor applications in fusion systems. 8 refs, 29 figs

  19. Tensile and fracture behavior of polymer foams

    International Nuclear Information System (INIS)

    Kabir, Md. E.; Saha, M.C.; Jeelani, S.

    2006-01-01

    Tensile and mode-I fracture behavior of cross-linked polyvinyl chloride (PVC) and rigid polyurethane (PUR) foams are examined. Tension tests are performed using prismatic bar specimens and mode-I fracture tests are performed using single edge notched bend (SENB) specimens under three-point bending. Test specimens are prepared from PVC foams with three densities and two different levels of cross-linking, and PUR foam with one density. Tension and quasi-static fracture tests are performed using a Zwick/Rowell test machine. Dynamic fracture tests are performed using a DYNATUP model 8210 instrumented drop-tower test set up at three different impact energy levels. Various parameters such as specimen size, loading rate, foam density, cross-linking, crack length, cell orientation (flow and rise-direction) and solid polymer material are studied. It is found that foam density and solid polymer material have a significant effect on tensile strength, modulus, and fracture toughness of polymer foams. Level of polymer cross-linking is also found to have a significant effect on fracture toughness. The presence of cracks in the rise- and flow direction as well as loading rate has minimal effect. Dynamic fracture behavior is found to be different as compared to quasi-static fracture behavior. Dynamic fracture toughness (K d ) increases with impact energy. Examination of fracture surfaces reveals that the fracture occurs in fairly brittle manner for all foam materials

  20. Microstructural evolution and tensile behavior of Ti{sub 2}AlNb alloys based α{sub 2}-phase decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei, E-mail: gackmol@163.com [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Zeng, Weidong, E-mail: zengwd@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Li, Dong; Zhu, Bin; Zheng, Youping [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Liang, Xiaobo [Beijing Iron & Steel Research Institute, Beijing 100081 (China)

    2016-04-26

    The formation mechanism of the fine plate-like O-phases within α{sub 2}-phases and tensile behavior of an isothermally forged Ti–22Al–25Nb (at%) orthorhombic alloy at 1040 °C during heat treatment were investigated. The investigation indicated that the alloys were heat-treated in O+B2 phase region after α{sub 2}+B2 phase region isothermally forging, the equiaxed α{sub 2}-phase was not stable and decomposed into O+α{sub 2} phases. The α{sub 2} phases formed during isothermal forging process have higher concentration of Nb and begun to decompose during O+B2 phase region heat treatment. And then the α{sub 2} phases separated into Niobium-lean and Niobium-rich regions through the Niobium diffusion: α{sub 2}→α{sub 2} (Nb-lean)+O (Nb-rich). Nb-rich regions with composition similar to Ti{sub 2}AlNb transformed to the O-phase, while the Nb-lean regions remained untransformed and retained the α{sub 2}-phase. The deformation behavior and fracture mechanism of Ti–22Al–25Nb alloy at room temperature were discussed. The deformation behavior and microstructural evolution of this alloy at different temperatures and stain rates were also investigated using uniaxial tensile test.

  1. Magnetic phase transitions and hydrostatic pressure or uniaxial stress experiments

    International Nuclear Information System (INIS)

    Bloch, D.

    1980-01-01

    Crystals submitted to high hydrostatic pressure or uniaxial stress have been investigated by means of neutron scattering. The techniques used are described and applications to pressure or stress induced T = 0 magnetic to nonmagnetic transitions (Pr,PrSb) and continuous to discontinuous order-disorder transitions (MnO) are given. (orig.)

  2. Functional possibilities of nonlinear crystals for frequency conversion: uniaxial crystals

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, Yu M [Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch of the Russian Academy of Sciences, Tomsk (Russian Federation); Arapov, Yu D; Kasyanov, I V [E.I. Zababakhin All-Russian Scientific-Research Institute of Technical Physics, Russian Federal Nuclear Centre, Snezhinsk, Chelyabinsk region (Russian Federation); Grechin, S G; Nikolaev, P P [N.E. Bauman Moscow State Technical University, Moscow (Russian Federation)

    2016-01-31

    The method and results of the analysis of phase-matching and nonlinear properties for all point groups of symmetry of uniaxial crystals that determine their functional possibilities for solving various problems of nonlinear frequency conversion of laser radiation are presented. (nonlinear optical phenomena)

  3. Technique for measurements of plane waves of uniaxial strain

    International Nuclear Information System (INIS)

    Graham, R.A.

    1977-01-01

    The measurement of plane waves in uniaxial strain, in which large surface areas are loaded and the measurements are restricted to a central region that is not influenced by lateral boundaries, is discussed. Measuring techniques are covered and instruments are discussed

  4. Chamber for uniaxial pressure application at low temperatures

    International Nuclear Information System (INIS)

    Grillo, M.L.N.; Carmo, L.C.S. do; Picon, A.P.

    1984-08-01

    A chamber for alignment of low temperature ferroelastic domains in crystals by the use of uniaxial stress was built. The system allows the use of EPR and optical techniques, as well as X-ray irradiation at temperatures as low as 77K. (Author) [pt

  5. Microwave holography in a uniaxial anial anisotropic plasma

    International Nuclear Information System (INIS)

    Nagai, Keinosuke; Suzuki, Michio

    1974-01-01

    Properties of a hologram constructed in a uniaxial anisotropic medium, namely in a gyro-plasma were investigated theoretically. We considered the interference patterns of ordinary waves and extraordinary waves from a source such as a hologram. An element of permitivity tensor can be measured by the reconstruction process from this hologram. (auth.)

  6. Effect of hexane treatment and uniaxial stretching on bending ...

    African Journals Online (AJOL)

    PVDF) film was studied. The quantity, β31, defined as the bending piezoelectric stress constant, was calculated. After hexane treatment and uniaxial stretching of the PVDF film, the value of β31 was 5.75 mV/m and 8.00 mV/m for draw ratio of ...

  7. Acoustic emission analysis on tensile failure of steam-side oxide scales formed on T22 alloy superheater tubes

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jun-Lin; Zhou, Ke-Yi, E-mail: boiler@seu.edu.cn; Xu, Jian-Qun [Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu Province (China); Wang, Xin-Meng; Tu, Yi-You [School of Materials Science and Engineering, Southeast University, Nanjing 210096, Jiangsu Province (China)

    2014-07-28

    Failure of steam-side oxide scales on boiler tubes can seriously influence the safety of coal-fired power plants. Uniaxial tensile tests employing acoustic emission (AE) monitoring were performed, in this work, to investigate the failure behavior of steam-side oxide scales on T22 alloy boiler superheater tubes. The characteristic frequency spectra of the captured AE signals were obtained by performing fast Fourier transform. Three distinct peak frequency bands, 100-170, 175-250, and 280-390 kHz, encountered in different testing stages were identified in the frequency spectra, which were confirmed to, respectively, correspond to substrate plastic deformation, oxide vertical cracking, and oxide spalling with the aid of scanning electronic microscopy observations, and can thus be used for distinguishing different oxide failure mechanisms. Finally, the critical cracking strain of the oxide scale and the interfacial shear strength of the oxide/substrate interface were estimated, which are the critical parameters urgently desired for modeling the failure behavior of steam-side oxide scales on boiler tubes of coal-fired power plants.

  8. Acoustic emission analysis on tensile failure of steam-side oxide scales formed on T22 alloy superheater tubes

    Science.gov (United States)

    Huang, Jun-Lin; Zhou, Ke-Yi; Wang, Xin-Meng; Tu, Yi-You; Xu, Jian-Qun

    2014-07-01

    Failure of steam-side oxide scales on boiler tubes can seriously influence the safety of coal-fired power plants. Uniaxial tensile tests employing acoustic emission (AE) monitoring were performed, in this work, to investigate the failure behavior of steam-side oxide scales on T22 alloy boiler superheater tubes. The characteristic frequency spectra of the captured AE signals were obtained by performing fast Fourier transform. Three distinct peak frequency bands, 100-170, 175-250, and 280-390 kHz, encountered in different testing stages were identified in the frequency spectra, which were confirmed to, respectively, correspond to substrate plastic deformation, oxide vertical cracking, and oxide spalling with the aid of scanning electronic microscopy observations, and can thus be used for distinguishing different oxide failure mechanisms. Finally, the critical cracking strain of the oxide scale and the interfacial shear strength of the oxide/substrate interface were estimated, which are the critical parameters urgently desired for modeling the failure behavior of steam-side oxide scales on boiler tubes of coal-fired power plants.

  9. Acoustic emission analysis on tensile failure of steam-side oxide scales formed on T22 alloy superheater tubes

    International Nuclear Information System (INIS)

    Huang, Jun-Lin; Zhou, Ke-Yi; Xu, Jian-Qun; Wang, Xin-Meng; Tu, Yi-You

    2014-01-01

    Failure of steam-side oxide scales on boiler tubes can seriously influence the safety of coal-fired power plants. Uniaxial tensile tests employing acoustic emission (AE) monitoring were performed, in this work, to investigate the failure behavior of steam-side oxide scales on T22 alloy boiler superheater tubes. The characteristic frequency spectra of the captured AE signals were obtained by performing fast Fourier transform. Three distinct peak frequency bands, 100-170, 175-250, and 280-390 kHz, encountered in different testing stages were identified in the frequency spectra, which were confirmed to, respectively, correspond to substrate plastic deformation, oxide vertical cracking, and oxide spalling with the aid of scanning electronic microscopy observations, and can thus be used for distinguishing different oxide failure mechanisms. Finally, the critical cracking strain of the oxide scale and the interfacial shear strength of the oxide/substrate interface were estimated, which are the critical parameters urgently desired for modeling the failure behavior of steam-side oxide scales on boiler tubes of coal-fired power plants.

  10. Using hardness to model yield and tensile strength

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey A.; Dogan, Omer N.; Schrems, Karol K.

    2005-02-01

    The current direction in hardness research is towards smaller and smaller loads as nano-scale materials are developed. There remains, however, a need to investigate the mechanical behavior of complex alloys for severe environment service. In many instances this entails casting large ingots and making numerous tensile samples as the bounds of the operating environment are explored. It is possible to gain an understanding of the tensile strength of these alloys using room and elevated temperature hardness in conjunction with selected tensile tests. The approach outlined here has its roots in the work done by Tabor for metals and low alloy and carbon steels. This research seeks to extend the work to elevated temperatures for multi-phase, complex alloys. A review of the approach will be given after which the experimental data will be examined. In particular, the yield stress and tensile strength will be compared to their corresponding hardness based values.

  11. Effects of conventional welding and laser welding on the tensile strength, ultimate tensile strength and surface characteristics of two cobalt-chromium alloys: a comparative study.

    Science.gov (United States)

    Madhan Kumar, Seenivasan; Sethumadhava, Jayesh Raghavendra; Anand Kumar, Vaidyanathan; Manita, Grover

    2012-06-01

    The purpose of this study was to evaluate the efficacy of laser welding and conventional welding on the tensile strength and ultimate tensile strength of the cobalt-chromium alloy. Samples were prepared with two commercially available cobalt-chromium alloys (Wironium plus and Diadur alloy). The samples were sectioned and the broken fragments were joined using Conventional and Laser welding techniques. The welded joints were subjected to tensile and ultimate tensile strength testing; and scanning electron microscope to evaluate the surface characteristics at the welded site. Both on laser welding as well as on conventional welding technique, Diadur alloy samples showed lesser values when tested for tensile and ultimate tensile strength when compared to Wironium alloy samples. Under the scanning electron microscope, the laser welded joints show uniform welding and continuous molt pool all over the surface with less porosity than the conventionally welded joints. Laser welding is an advantageous method of connecting or repairing cast metal prosthetic frameworks.

  12. Enhanced electron-lattice coupling under uniaxial stress in layered double hydroxides intercalated with samarium complexes

    International Nuclear Information System (INIS)

    Park, Ta-Ryeong

    2004-01-01

    We have applied uniaxial stress to samarium complexes by intercalating them into the gallery of a layered material and by using a diamond-anvil cell at 28 K. Although uniaxial stress reduces symmetry and removes degeneracy, the overall number of photoluminescence (PL) peaks evidently decreased with the application of uniaxial stress. This contradictory observation is explained by an increased electron-lattice coupling strength under uniaxial stress. This behavior is also confirmed by time-resolved PL data.

  13. Study of the thickness evolution during SPT Testing

    Directory of Open Access Journals (Sweden)

    David Sánchez-Ávila

    2018-03-01

    Full Text Available The Small Punch Test (SPT is an increasingly expanding test used to obtain different mechanical data, such as strength, fracture, creep, etc…especially when there is little material available. However, the SPT test is more complicated than the uniaxial tensile test due to its non-linearity, which makes it difficult to relate the data obtained with the tensile tests. In fact, in the literature there is no clear model linking these tests and a different calibration should be used for each material. The complication of the SPT test is that the reduction of the sample thickness is not homogeneous in its gauge volume. In this work we proceeded to determine the variation of the SPT specimen thickness at several points, especially at the center and at the rupture zone, by means of the use of finite elements in COMSOL, taking a SLM AM (selective laser melting additive manufactured 316L stainless steel as the base material for modelling. For the appropriate modelling in COMSOL, the mechanical parameters of two 316L extreme thermomechanical treatments have been implemented, one annealed to a minimum hardness and another heavily work-hardened. The sample thickness variation results allow advancing in the theoretical modeling of the SPT behavior in order to obtain more accurate correlations with tensile tests data.

  14. Magnetism and Raman Spectroscopy of Pristine and Hydrogenated TaSe2 Monolayer tuned by Tensile and Pure Shear Strain

    Science.gov (United States)

    Chowdhury, Sugata; Simpson, Jeffrey; Einstein, T. L.; Walker, Angela R. Hight

    2D-materials with controllable optical, electronic and magnetic properties are desirable for novel nanodevices. Here we studied these properties for both pristine and hydrogenated TaSe2 (TaSe2-H) monolayer (ML) in the framework of DFT using the PAW method. We considered uniaxial and biaxial tensile strain, as well as shear strain along the basal planes in the range between 1% and 16%. Previous theoretical works (e.g.) considered only symmetrical biaxial tensile. Pristine ML is ferromagnetic for uniaxial tensile strain along ◯ or ŷ. For tensile strain in ŷ, the calculated magnetic moments of the Ta atoms are twice those for the same strain in ◯. Under pure shear strain (expansion along ŷ and compression along ◯), a pristine ML is ferromagnetic, but becomes non-magnetic when the strain directions are interchanged. Due to carrier-mediated double-exchange, the pristine ML is ferromagnetic when the Se-Ta-Se bond angle is < 82° and the ML thickness is < 3.25Å. We find that all Raman-active phonon modes show obvious red-shifting due to bond elongation and the E2 modes degeneracy is lifted as strain increases. For a TaSe2-H ML, the same trends were observed. Results show the ability to tune the properties of 2D-materials.

  15. Study on Relaxation Damage Properties of High Viscosity Asphalt Sand under Uniaxial Compression

    Directory of Open Access Journals (Sweden)

    Yazhen Sun

    2018-01-01

    Full Text Available Laboratory investigations of relaxation damage properties of high viscosity asphalt sand (HVAS by uniaxial compression tests and modified generalized Maxwell model (GMM to simulate viscoelastic characteristics coupling damage were carried out. A series of uniaxial compression relaxation tests were performed on HVAS specimens at different temperatures, loading rates, and constant levels of input strain. The results of the tests show that the peak point of relaxation modulus is highly influenced by the loading rate in the first half of an L-shaped curve, while the relaxation modulus is almost constant in the second half of the curve. It is suggested that for the HVAS relaxation tests, the temperature should be no less than −15°C. The GMM is used to determine the viscoelastic responses, the Weibull distribution function is used to characterize the damage of the HVAS and its evolution, and the modified GMM is a coupling of the two models. In this paper, the modified GMM is implemented through a secondary development with the USDFLD subroutine to analyze the relaxation damage process and improve the linear viscoelastic model in ABAQUS. Results show that the numerical method of coupling damage provides a better approximation of the test curve over almost the whole range. The results also show that the USDFLD subroutine can effectively predict the relaxation damage process of HVAS and can provide a theoretical support for crack control of asphalt pavements.

  16. Analysis of Symmetric Reinforcement of Quasi-Isotropic Graphite-Epoxy Plates with a Circular Cutout under Uniaxial Tensile Loading.

    Science.gov (United States)

    1983-12-01

    DISTRIBUTION LIST ............... 111 . •6 a’. . .’. ’’. ’’2"-;’,".".,:’..."-’’:’ .-.-. .-;.: ś " - "." "-" - ,".-",’-’-"...--..’%° -,’:’, LISr OF...Locations anld Szrain a 10,000 psi (Par Field) ... .. ..... . ... 96 W, :- .% .... 7 ".’ , .9. LISr OF FIGURES 2.1 Reinforcement Configuration, Iype 1

  17. Final report on in-reactor uniaxial tensile deformation of pure iron and Fe-Cr alloy

    DEFF Research Database (Denmark)

    Singh, Bachu Narain; Huang, X.; Tähtinen, S.

    , the in-reactor deformation leads to accumulation of dislocations in a homogeneous fashion and only to a modest density. No dislocation cells are formed during the in-reactor or post-irradiation deformation of Fe-Cr and pure iron. Furthermore, in both cases, the slip systems even in the planes with Schmid...... factor value of almost zero get activated during the in-reactor as well as post-irradiation deformation. The main implications of these results are briefly discussed....

  18. Understanding the effect of uniaxial tensile strain on the early stages of sensitization in AISI 304 austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, P.S., E-mail: psc0126@gmail.com [Techno India Agartala, Maheshkhola, Agartala, West Tripura PIN – 799004 (India); Guchhait, S.K.; Mitra, P.K. [Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700032 (India); Mukherjee, P.; Gayathri, N. [Variable Energy Cyclotron Centre (VECC), 1/AF Bidhan Nagar, Kolkata 700064 (India); Mitra, M.K. [Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700032 (India)

    2015-04-01

    In the present study, an attempt has been made to understand the effect of different competing mechanisms controlling the overall degree of sensitization (DOS) of deformed austenitic stainless steel at the early stage of sensitization. The Double Loop Electrochemical Potentiokinetic Reactivation (DL-EPR) studies were performed to characterize the Degree of Sensitization (DOS) as a function of both pre-defined strain and sensitization temperature. X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were used to explain the phenomena qualitatively. A non monotonous behaviour in the variation of DOS has been observed with deformation and sensitization temperature. The presence of Deformation Induced Martensites (DIM) and their transformation into tempered martensites (α + M{sub 23}C{sub 6}) at higher temperatures was found to play major roles in controlling the overall sensitization and desensitization processes. - Highlights: • Interplay of various dynamic processes (four) in the early sensitization. • Deformation induced martensite (α′) playing major role at low temperature. • α (Tempered martensite) induced processes plays a vital role at higher temperatures. • Results in non monotonous variation in degree of sensitisation (DOS)

  19. Cyclic tensile response of Mo-27 at% Re and Mo-0.3 at% Si solid solution alloys

    Energy Technology Data Exchange (ETDEWEB)

    Yu, X.J.; Kumar, K.S., E-mail: Sharvan_Kumar@brown.edu

    2016-10-31

    Stress-controlled uniaxial cyclic tensile tests were conducted on binary Mo-27 at% Re and Mo-0.3 at% Si solid solutions as a function of temperature and compared against the previously reported cyclic response of pure Mo. The Mo-27 at% Re alloy with a recrystallized grain size of ~30 µm was evaluated in the temperature range 25 °C–800 °C at R=0.1 and stress range that was 80% of the ultimate tensile strength (UTS); a peak in fatigue life was observed between 300 °C and 500 °C. The decrease in fatigue life at the higher temperatures of 700 °C and 800 °C is attributed to dynamic strain aging. Transmission electron microscopy of the cyclically-deformed alloy revealed parallel bands of dislocation at room temperature that transitioned to a uniform cell structure at 500 °C and back to orthogonal planar arrays at 800 °C. The as-extruded Mo-0.3 at% Si alloy was evaluated from 25 °C to 1200 °C and showed superior fatigue life and ratcheting strain resistance as compared to pure Mo and the Mo-27 at% Re alloy (within the temperature range where data were available for comparison). The superior resistance is attributed to the high density of dislocations within the material in this mostly unrecrystallized state rather than Si in solid solution. Above 800 °C, the ratcheting strain increases and fatigue life decreases rapidly with increasing temperature and is associated with dynamic recovery.

  20. Strength and stiffness of uniaxially tensioned reinforced concrete panels subjected to membrane shear. Technical report

    International Nuclear Information System (INIS)

    Hilmy, S.I.; White, R.N.; Gergely, P.

    1982-06-01

    This report presents experimental and analytical results on internal pressurization effects and seismic shear effects in a concrete containment vessel that is cracked by tension in one direction only. The experimental program, which was restricted to 6 in. thick flat specimens with two-way reinforcement, included establishment of (a) extensional stiffness for uniaxially tensioned specimens stressed to 0.6fy, and (b) shear strength and stiffness of these cracked specimens with tension levels ranging from 0 to 0.9fy; values were about 10 to 15 percent higher than in similar biaxially tensioned specimens. Eleven (11) specimens were tested (6 in monotonic shear and 5 in reversing cyclic shear)

  1. In-situ white beam microdiffraction study of the deformation behavior in polycrystalline magnesium alloy during uniaxial loading

    International Nuclear Information System (INIS)

    Advanced Light Source; Tamura, Nobumichi; Lynch, P.A.; Stevenson, A.W.; Liang, D.; Parry, D.; Wilkins, S.; Madsen, I.C.; Bettles, C.; Tamura, N.; Geandier, G.

    2007-01-01

    Scanning white beam X-ray microdiffraction has been used to study the heterogeneous grain deformation in a polycrystalline Mg alloy (MgAZ31). The high spatial resolution achieved on beamline 7.3.3 at the Advanced Light Source provides a unique method to measure the elastic strain and orientation of single grains as a function of applied load. To carry out in-situ measurements a light weight (∼0.5kg) tensile stage, capable of providing uniaxial loads of up to 600kg, was designed to collect diffraction data on the loading and unloading cycle. In-situ observation of the deformation process provides insight about the crystallographic deformation mode via twinning and dislocation slip

  2. Development of a new ultrafine grained dual phase steel and examination of the effect of grain size on tensile deformation behavior

    Energy Technology Data Exchange (ETDEWEB)

    Saeidi, N., E-mail: navidsae@gmail.com; Ashrafizadeh, F.; Niroumand, B.

    2014-04-01

    Ultrafine grained dual phase (DP) steels are among the newest grades of DP steels that incorporate the uniform distribution of fine martensite particles (in the order of 1–2 μm) within a ferrite matrix. These new grades of steels have been developed in response to the world's demand for decreasing the fuel consumption in automobiles by increasing the strength to weight ratio. In the present research, a new kind of ultrafine grained DP (UFG-DP) steel with an average grain size of about 2 μm as well as a coarse grained DP (CG-DP) steel with an average grain size of about 5.4 μm was produced by consecutive intercritical annealing and cold rolling of low carbon AISI 8620 steel. The martensite volume fraction for both microstructures was the same and about 50 percent. Scanning electron microscopy (SEM) microstructural examination and room temperature tensile deformation analyses were performed on both UFG-DP and CG-DP steels and their deformation behavior in terms of strength, elongation and strain hardening was studied and compared. Room-temperature uniaxial tensile tests revealed that for a given martensite volume fraction, yield and tensile strengths were not very sensitive to martensite morphology. However, uniform and total elongation values were noticeably affected by refining martensite particles. The higher plasticity of fine martensite particles as well as the more uniform strain distribution within the UFG-DP microstructure resulted in higher strain hardenability and, finally, the higher ductility of the UFG-DP steel.

  3. The tensile strength of mechanical joint prototype of lontar fiber composite

    Science.gov (United States)

    Bale, Jefri; Adoe, Dominggus G. H.; Boimau, Kristomus; Sakera, Thomas

    2018-03-01

    In the present study, an experimental activity has been programmed to investigate the effect of joint prototype configuration on tensile strength of lontar (Borassus Flabellifer) fiber composite. To do so, a series of tests were conducted to establish the tensile strength of different joint prototype configuration specimen of lontar fiber composite. In addition, post observation of macroscope was used to map damage behavior. The analysis of lontar fiber composite is a challenge since the material has limited information than others natural fiber composites materials. The results shown that, under static tensile loading, the tensile strength of 13 MPa produced by single lap joint of lontar fiber composite is highest compare to 11 MPa of tensile strength generated by step lap joint and double lap joint where produced the lowest tensile strength of 6 MPa. It is concluded that the differences of tensile strength depend on the geometric dimensions of the cross-sectional area and stress distribution of each joint prototype configuration.

  4. Thermal and tensile properties of alumina filled PET nanocomposites

    Science.gov (United States)

    Nikam, Pravin N.; Deshpande, Vineeta D.

    2018-05-01

    In the present investigation, nanocomposites of poly(ethylene terephathalate)(PET) with different content (0 to 5 wt.%) of alumina nanoparticles (n-Al2O3) were prepared by melt-extrusion technique. Morphological characterization of samples was examined by transmission electron microscopy (TEM). Morphological analysis revealed that degree of dispersion of alumina nanoparticles (ANPs) was increased at lower content (i.e. upto 2 wt.%), which observed by TEM. Thermal and tensile measurements were carried out using and differential scanning calorimetry (DSC) and universal testing machine (UTM). The thermal analysis showed that the glass transition termperature (Tg), melting temperature (Tm), crystallization temperature (Tc) of PET/alumina nanocomposites (PNCs) were higher than neat PET (PET0). The heat enthalpy (ΔHm) of crystallization for PNCs was increased compared to PET0, which indicates that degree of crystallinity of PNCs also increased compared to PET0. The half-time (t0.5) of crystallization of PNCs were decreased compared to PET0 which indicates that the incorporation of ANPs nucleate the PET molecular chains and allowing the easily crystallization during nonisothermal process. The tensile analysis revealed that the tensile elastic modulus (i.e. Young's modulus) of PNCs increased almost linearly with increasing the content of ANPs while tensile elongation at break decreased nonlinearly. The tensile strength of PNCs increased with a 1 wt.% of ANPs whereas the higher content of ANPs decreased the tensile strength.

  5. Rheological-dynamical continuum damage model for concrete under uniaxial compression and its experimental verification

    Directory of Open Access Journals (Sweden)

    Milašinović Dragan D.

    2015-01-01

    Full Text Available A new analytical model for the prediction of concrete response under uniaxial compression and its experimental verification is presented in this paper. The proposed approach, referred to as the rheological-dynamical continuum damage model, combines rheological-dynamical analogy and damage mechanics. Within the framework of this approach the key continuum parameters such as the creep coefficient, Poisson’s ratio and damage variable are functionally related. The critical values of the creep coefficient and damage variable under peak stress are used to describe the failure mode of the concrete cylinder. The ultimate strain is determined in the post-peak regime only, using the secant stress-strain relation from damage mechanics. The post-peak branch is used for the energy analysis. Experimental data for five concrete compositions were obtained during the examination presented herein. The principal difference between compressive failure and tensile fracture is that there is a residual stress in the specimens, which is a consequence of uniformly accelerated motion of load during the examination of compressive strength. The critical interpenetration displacements and crushing energy are obtained theoretically based on the concept of global failure analysis. [Projekat Ministarstva nauke Republike Srbije, br. ON 174027: Computational Mechanics in Structural Engineering i br. TR 36017: Utilization of by-products and recycled waste materials in concrete composites for sustainable construction development in Serbia: Investigation and environmental assessment of possible applications

  6. Mechanical Property Measurements and Fracture Propagation Analysis of Longmaxi Shale by Micro-CT Uniaxial Compression

    Directory of Open Access Journals (Sweden)

    Minyue Zhou

    2018-05-01

    Full Text Available The mechanical properties and fracture propagation of Longmaxi shale loading under uniaxial compression were measured using eight cylindrical shale specimens (4 mm in diameter and 8 mm in height, with the bedding plane oriented at 0° and 90° to the axial loading direction, respectively, by micro computed tomography (micro-CT. Based on the reconstructed three-dimensional (3-D CT images of cracks, different stages of the crack growth process in the 0° and 90° orientation specimen were revealed. The initial crack generally occurred at relatively smaller loading force in the 0° bedding direction specimen, mainly in the form of tensile splitting along weak bedding planes. Shear sliding fractures were dominant in the specimens oriented at 90°, with a small number of parallel cracks occurring on the bedding plane. The average thickness and volume of cracks in the 90° specimen is higher than those for the specimen oriented at 0°. The geometrical characterization of fractures segmented from CT scan binary images shows that a specific surface area correlates with tortuosity at the different load stages of each specimen. The 3-D box-counting dimension (BCD calculations can accurately reflect crack evolution law in the shale. The results indicate that the cracks have a more complex pattern and rough surface at an orientation of 90°, due to crossed secondary cracks and shear failure.

  7. Diffraction Plane Dependence of Micro Residual Stresses in Uniaxially Extended Carbon Steels

    Directory of Open Access Journals (Sweden)

    T. Hanabusa

    2010-12-01

    Full Text Available In the stress measurement using X-ray or neutron diffraction, an elastic anisotropy as well as a plastic anisotropy of crystal must be carefully considered. In the X-ray and neutron diffraction stress measurement for polycrystalline materials, a particular {hkl} plane is used in measuring lattice strains. The dependence of an X-ray elastic constant on a diffraction plane is a typical example caused by an elastic anisotropy of the crystal. The yield strength and the work hardening rate of a single crystal depend on a crystallographic direction of the crystal. The difference in the yield strength and the work hardening rate relating to the crystallographic direction develops different residual stresses measured on each {hkl} diffraction after plastic deformation of a polycrystalline material. The present paper describes the result of the neutron stress measurement on uniaxially extended low and middle carbon steels. A tri-axial residual stress state developed in the extended specimens was measured on different kind of {hkl} diffraction plane. The measurement on the {110}, {200} and {211} diffraction showed that residual stresses increased with increasing the plastic elongation and the residual stresses on {110} were compressive, {200} were tensile and those on {211} were the middle of the former two planes.

  8. Largely Tunable Band Structures of Few-Layer InSe by Uniaxial Strain.

    Science.gov (United States)

    Song, Chaoyu; Fan, Fengren; Xuan, Ningning; Huang, Shenyang; Zhang, Guowei; Wang, Chong; Sun, Zhengzong; Wu, Hua; Yan, Hugen

    2018-01-31

    Because of the strong quantum confinement effect, few-layer γ-InSe exhibits a layer-dependent band gap, spanning the visible and near infrared regions, and thus recently has been drawing tremendous attention. As a two-dimensional material, the mechanical flexibility provides an additional tuning knob for the electronic structures. Here, for the first time, we engineer the band structures of few-layer and bulk-like InSe by uniaxial tensile strain and observe a salient shift of photoluminescence peaks. The shift rate of the optical gap is approximately 90-100 meV per 1% strain for four- to eight-layer samples, which is much larger than that for the widely studied MoS 2 monolayer. Density functional theory calculations well reproduce the observed layer-dependent band gaps and the strain effect and reveal that the shift rate decreases with the increasing layer number for few-layer InSe. Our study demonstrates that InSe is a very versatile two-dimensional electronic and optoelectronic material, which is suitable for tunable light emitters, photodetectors, and other optoelectronic devices.

  9. Thermal effects on the enhanced ductility in non-monotonic uniaxial tension of DP780 steel sheet

    Science.gov (United States)

    Majidi, Omid; Barlat, Frederic; Korkolis, Yannis P.; Fu, Jiawei; Lee, Myoung-Gyu

    2016-11-01

    To understand the material behavior during non-monotonic loading, uniaxial tension tests were conducted in three modes, namely, the monotonic loading, loading with periodic relaxation and periodic loading-unloadingreloading, at different strain rates (0.001/s to 0.01/s). In this study, the temperature gradient developing during each test and its contribution to increasing the apparent ductility of DP780 steel sheets were considered. In order to assess the influence of temperature, isothermal uniaxial tension tests were also performed at three temperatures (298 K, 313 K and 328 K (25 °C, 40 °C and 55 °C)). A digital image correlation system coupled with an infrared thermography was used in the experiments. The results show that the non-monotonic loading modes increased the apparent ductility of the specimens. It was observed that compared with the monotonic loading, the temperature gradient became more uniform when a non-monotonic loading was applied.

  10. Influence of an uniaxial stress on point defects

    International Nuclear Information System (INIS)

    Beuneu, B.

    1984-03-01

    We study two effects of an elastic external uniaxial stress on point defects (created by electron irradiation): 1.- We measure the linear variation of their resistivity rhosub(D) under the elastic strain epsilon in Copper. It gives the specific elastoresistivity (E.R.S.) chisub(D)=delta rhosub(D)/epsilon. With the help of the results of VON STEBUT (fast neutrons) we show that the E.R.S. is characteristic of a defect and of its configuration. 2.- By means of resistivity measurements in molybdenum, we observe a paraelastic phenomenon. It is thermally activated (νsub(0) approximately= 10 12 s -1 and E approximately= 72 meV) and we attribute it to the reorientation of a dumbell interstitial under the uniaxial stress. The resistivity of this dumbbell is higher along its axis than perpendicularly to it. We have completed these results with some configuration energy calculations for the dumbbell and with a simple kinetic model [fr

  11. Uniaxially stressed Ge:Ga and Ge:Be

    Energy Technology Data Exchange (ETDEWEB)

    Dubon, Jr., Oscar Danilo [Univ. of California, Berkeley, CA (United States)

    1992-12-01

    The application of a large uniaxial stress to p-type Ge single crystals changes the character of both the valence band and the energy levels associated with the acceptors. Changes include the splitting of the fourfold degeneracy of the valence band top and the reduction of the ionization energy of shallow acceptors. In order to study the effect of uniaxial stress on transport properties of photoexcited holes, a variable temperature photo-Hall effect system was built in which stressed Ge:Ga and Ge:Be could be characterized. Results indicate that stress increases the lifetime and Hall mobility of photoexcited holes. These observations may help further the understanding of fundamental physical processes that affect the performance of stressed Ge photoconductors including the capture of holes by shallow acceptors.

  12. Crystallinity of polyethylene in uni-axial extensional flow

    DEFF Research Database (Denmark)

    Wingstrand, Sara Lindeblad; van Drongelen, Martin; Mortensen, Kell

    Flow history of polymer melts in processing greatly influences the crystallinity and hence the solid properties of the final material. A wide range of polymer processes involve extensional flows e.g. fiber spinning, blow moulding etc. However, due to instrumental difficulties, experimental studies...... on polymer crystallization in controlled uniaxial extension are quite rare compared to studies of crystallization in shear. Inherently uniaxial extensional flows are strong and simple relative to shear flows, in the sense that chain stretch is easily obtained and that the molecules experience no tumbling...... such that crystallization from a stretched state can take place. In this work we explore this feature in the attempt to link the nonlinear extensional rheology to the final morphology. We investigate polyethylenes (PE) of various chain architectures and observe that, even for complex architectures like long chain branched...

  13. General multimode polarization splitter design in uniaxial media

    Science.gov (United States)

    Teixeira, Poliane A.; Silva, Daniely G.; Gabrielli, Lucas H.; Spadoti, Danilo H.; Junqueira, Mateus A. F. C.

    2018-03-01

    Quasiconformal transformation optics is used to design two-dimensional polarization beam splitters. The resulting media present inhomogeneous uniaxial permittivity and nonmagnetic response. The compact devices are theoretically designed and investigated for symmetrical and asymmetrical geometries, with footprint of 64 and 110 μm2, respectively. The polarization splitter performance is evaluated for the fundamental mode and third mode, exhibiting an insertion loss closer to 0 dB and extinction ratio above 40 dB over a broad wavelength range.

  14. Field-Induced Rheology in Uniaxial and Biaxial Fields

    International Nuclear Information System (INIS)

    MARTIN, JAMES E.

    1999-01-01

    Steady and oscillatory shear 3-D simulations of electro- and magnetorheology in uniaxial and biaxial fields are presented, and compared to the predictions of the chain model. These large scale simulations are three dimensional, and include the effect of Brownian motion. In the absence of thermal fluctuations, the expected shear thinning viscosity is observed in steady shear, and a striped phase is seen to rapidly form in a uniaxial field, with a shear slip zone in each sheet. However, as the influence of Brownian motion increases, the fluid stress decreases, especially at lower Mason numbers, and the striped phase eventually disappears, even when the fluid stress is still high. In a biaxial field, an opposite trend is seen, where Brownian motion decreases the stress most significantly at higher Mason numbers. to account for the uniaxial steady shear data they propose a microscopic chain model of the role played by thermal fluctuations on the rheology of ER and MR fluids that delineates the regimes where an applied field can impact the fluid viscosity, and gives an analytical prediction for the thermal effect. In oscillatory shear, a striped phase again appears in uniaxial field, at strain amplitudes greater than(approx) 0.15, and the presence of a shear slip zone creates strong stress nonlinearities at low strain amplitudes. In a biaxial field, a shear slip zone is not created, and so the stress nonlinearities develop only at expected strain amplitudes. The nonlinear dynamics of these systems is shown to be in good agreement with the Kinetic Chain Model

  15. Ultrasonic detection of cracks in uniaxial glass fibre rods

    CSIR Research Space (South Africa)

    Loveday, PW

    2006-01-01

    Full Text Available Conference on Computational and Applied Mechanics SACAM06 Cape Town, 16-18 January 2006 �SACAM ULTRASONIC DETECTION OF CRACKS IN UNIAXIAL GLASS FIBRE RODS Derren Wood and Philip Loveday Sensor Science and Technology, CSIR Materials Science... means of detecting internal and/or surface damage in composites which is safe, quick and relatively cost effective. Various ultrasonic techniques have been applied in the past to detect defects in composite media, the most well known being perhaps...

  16. Strength of SiCf-SiCm composite tube under uniaxial and multiaxial loading

    Science.gov (United States)

    Shapovalov, Kirill; Jacobsen, George M.; Alva, Luis; Truesdale, Nathaniel; Deck, Christian P.; Huang, Xinyu

    2018-03-01

    The authors report mechanical strength of nuclear grade silicon carbide fiber reinforced silicon carbide matrix composite (SiCf-SiCm) tubing under several different stress states. The composite tubing was fabricated via a Chemical Vapor Infiltration (CVI) process, and is being evaluated for accident tolerant nuclear fuel cladding. Several experimental techniques were applied including uniaxial tension, elastomer insert burst test, open and closed end hydraulic bladder burst test, and torsion test. These tests provided critical stress and strain values at proportional limit and at ultimate failure points. Full field strain measurements using digital image correlation (DIC) were obtained in order to acquire quantitative information on localized deformation during application of stress. Based on the test results, a failure map was constructed for the SiCf-SiCm composites.

  17. Tensile strained gray tin: Dirac semimetal for observing negative magnetoresistance with Shubnikov-de Haas oscillations

    Science.gov (United States)

    Huang, Huaqing; Liu, Feng

    2017-05-01

    The extremely stringent requirement on material quality has hindered the investigation and potential applications of exotic chiral magnetic effect in Dirac semimetals. Here, we propose that gray tin is a perfect candidate for observing the chiral anomaly effect and Shubnikov-de-Haas (SdH) oscillation at relatively low magnetic field. Based on effective k .p analysis and first-principles calculations, we discover that gray tin becomes a Dirac semimetal under tensile uniaxial strain, in contrast to a topological insulator under compressive uniaxial strain as known before. In this newly found Dirac semimetal state, two Dirac points which are tunable by tensile [001] strains lie in the kz axis and Fermi arcs appear in the (010) surface. Due to the low carrier concentration and high mobility of gray tin, a large chiral anomaly induced negative magnetoresistance and a strong SdH oscillation are anticipated in this half of the strain spectrum. Comparing to other Dirac semimetals, the proposed Dirac semimetal state in the nontoxic elemental gray tin can be more easily manipulated and accurately controlled. We envision that gray tin provides a perfect platform for strain engineering of chiral magnetic effects by sweeping through the strain spectrum from positive to negative and vice versa.

  18. Analysis of the Mechanical Behavior, Creep Resistance and Uniaxial Fatigue Strength of Martensitic Steel X46Cr13

    Science.gov (United States)

    Brnic, Josip; Krscanski, Sanjin; Lanc, Domagoj; Brcic, Marino; Turkalj, Goran; Canadija, Marko; Niu, Jitai

    2017-01-01

    The article deals with the analysis of the mechanical behavior at different temperatures, uniaxial creep and uniaxial fatigue of martensitic steel X46Cr13 (1.4034, AISI 420). For the purpose of considering the aforementioned mechanical behavior, as well as determining the appropriate resistance to creep and fatigue strength levels, numerous uniaxial tests were carried out. Tests related to mechanical properties performed at different temperatures are presented in the form of engineering stress-strain diagrams. Short-time creep tests performed at different temperatures and different stress levels are presented in the form of creep curves. Fatigue tests carried out at stress ratios R=0.25 and R=−1 are shown in the form of S–N (fatigue) diagrams. The finite fatigue regime for each of the mentioned stress ratios is modeled by an inclined log line, while the infinite fatigue regime is modeled by a horizontal line, which represents the fatigue limit of the material and previously was calculated by the modified staircase method. Finally, the fracture toughness has been calculated based on the Charpy V-notch impact energy. PMID:28772749

  19. An Investigation of the Uniaxial Compressive Strength of a Cemented Hydraulic Backfill Made of Alluvial Sand

    Directory of Open Access Journals (Sweden)

    Guangsheng Liu

    2017-01-01

    Full Text Available Backfill is commonly used in underground mines. The quality control of the backfill is a key step to ensure it meets the designed strength requirement. This is done through sample collection from the underground environment, followed by uniaxial compression tests to obtain the Uniaxial Compressive Strength (UCS in the laboratory. When the cylindrical cemented backfill samples are axially loaded to failure, several failure modes can be observed and mainly classified into diagonal shear failure and axial split failure. To date, the UCS obtained by these two failure modes are considered to be the same with no distinction between them. In this paper, an analysis of the UCS results obtained on a cemented hydraulic backfill made of alluvial sand at a Canadian underground mine over the course of more than three years is presented. The results show that the UCS values obtained by diagonal shear failure are generally higher than those obtained by axial split failure for samples with the same recipe and curing time. This highlights the importance of making a distinction between the UCS values obtained by the two different modes of failure. Their difference in failure mechanism is explained. Further investigations on the sources of the data dispersion tend to indicate that the UCS obtained by laboratory tests following the current practice may not be representative of the in-situ strength distribution in the underground stopes due to segregation in cemented hydraulic backfill.

  20. A uniaxial cyclic elastoplastic constitutive law with a discrete memory variable

    International Nuclear Information System (INIS)

    Taheri, S.

    1991-01-01

    At present, the study on cyclic elastoplastic constitutive laws is focused on nonproportional loading, but for uniaxial loading, some problems still exist. For example, the possibility for a law to describe simultaneously the ratcheting in nonsymmetrical load-controlled test, elastic and plastic shakedown in symmetrical and nonsymmetrical ones. Here a law is presented, which in addition to previous phenomena, describes the cyclic hardening in a pushpull test, the cyclic softening after overloading and also the dependence of cyclic strain-stress curves on the history of loading. These are the usual properties of 316 stainless steel at room temperature. This law uses an internal discrete memory variable: the plastic strain at the last unloading. On the other hand, the choice of all macroscopic variables is justified by a microscopic analysis. This law has been also extended to a three-dimensional case. Regarding the microstructure under cyclic loading, plastic shakedown and ratcheting are discussed. The definition of macroscopic variables taking account of microstructure and uniaxial constitutive law are described. (K.I.)

  1. Tensile Mechanical Property of Oil Palm Empty Fruit Bunch Fiber Reinforced Epoxy Composites

    Science.gov (United States)

    Ghazilan, A. L. Ahmad; Mokhtar, H.; Shaik Dawood, M. S. I.; Aminanda, Y.; Ali, J. S. Mohamed

    2017-03-01

    Natural, short, untreated and randomly oriented oil palm empty fruit bunch fiber reinforced epoxy composites were manufactured using vacuum bagging technique with 20% fiber volume composition. The performance of the composite was evaluated as an alternative to synthetic or conventional reinforced composites. Tensile properties such as tensile strength, modulus of elasticity and Poisson’s ratio were compared to the tensile properties of pure epoxy obtained via tensile tests as per ASTM D 638 specifications using Universal Testing Machine INSTRON 5582. The tensile properties of oil palm empty fruit bunch fiber reinforced epoxy composites were lower compared to plain epoxy structure with the decrement in performances of 38% for modulus of elasticity and 61% for tensile strength.

  2. Experimental Investigation of the Influence of Joint Geometric Configurations on the Mechanical Properties of Intermittent Jointed Rock Models Under Cyclic Uniaxial Compression

    Science.gov (United States)

    Liu, Yi; Dai, Feng; Fan, Pengxian; Xu, Nuwen; Dong, Lu

    2017-06-01

    Intermittent joints in rock mass are quite sensitive to cyclic loading conditions. Understanding the fatigue mechanical properties of jointed rocks is beneficial for rational design and stability analysis of rock engineering projects. This study experimentally investigated the influences of joint geometry (i.e., dip angle, persistency, density and spacing) on the fatigue mechanism of synthetic jointed rock models. Our results revealed that the stress-strain curve of jointed rock under cyclic loadings is dominated by its curve under monotonic uniaxial loadings; the terminal strain in fatigue curve is equal to the post-peak strain corresponding to the maximum cyclic stress in the monotonic stress-strain curve. The four joint geometrical parameters studied significantly affect the fatigue properties of jointed rocks, including the irreversible strains, the fatigue deformation modulus, the energy evolution, the damage variable and the crack coalescence patterns. The higher the values of the geometrical parameters, the lower the elastic energy stores in this jointed rock, the higher the fatigue damage accumulates in the first few cycles, and the lower the fatigue life. The elastic energy has certain storage limitation, at which the fatigue failure occurs. Two basic micro-cracks, i.e., tensile wing crack and shear crack, are observed in cyclic loading and unloading tests, which are controlled principally by joint dip angle and persistency. In general, shear cracks only occur in the jointed rock with higher dip angle or higher persistency, and the jointed rock is characterized by lower fatigue strength, larger damage variable and lower fatigue life.

  3. A comparative study on the uniaxial mechanical properties of the umbilical vein and umbilical artery using different stress-strain definitions.

    Science.gov (United States)

    Karimi, Alireza; Navidbakhsh, Mahdi

    2014-12-01

    The umbilical cord is part of the fetus and generally includes one umbilical vein (UV) and two umbilical arteries (UAs). As the saphenous vein and UV are the most commonly used veins for the coronary artery disease treatment as a coronary artery bypass graft (CABG), understating the mechanical properties of UV has a key asset in its performance for CABG. However, there is not only a lack of knowledge on the mechanical properties of UV and UA but there is no agreement as to which stress-strain definition should be implemented to measure their mechanical properties. In this study, the UV and UA samples were removed after caesarean from eight individuals and subjected to a series of tensile testing. Three stress definitions (second Piola-Kichhoff stress, engineering stress, and true stress) and four strain definitions (Almansi-Hamel strain, Green-St. Venant strain, engineering strain, and true strain) were employed to determine the linear mechanical properties of UVs and UAs. The nonlinear mechanical behavior of UV/UA was computationally investigated using hyperelastic material models, such as Ogden and Mooney-Rivlin. The results showed that the effect of varying the stress definition on the maximum stress measurements of the UV/UA is significant but not when calculating the elastic modulus. In the true stress-strain diagram, the maximum strain of UV was 92 % higher, while the elastic modulus and maximum stress were 162 and 42 % lower than that of UA. The Mooney-Rivlin material model was designated to represent the nonlinear mechanical behavior of the UV and UA under uniaxial loading.

  4. Tensile strength of glulam laminations of Nordic spruce

    DEFF Research Database (Denmark)

    Hoffmeyer, Preben; Bräuner, Lise; Boström, Lars

    1999-01-01

    Design of glulam according to the European timber code Eurocode 5 is based on the standard document prEN1194 , according to which glulam beam strength is to be established either by full scale testing or by calculation. The calculation must be based on a knowledge of lamination tensile strength....... This knowledge may be obtained either by adopting a general rule that the characteristic tensile strength is sixty percent of the characteristic bending strength, or by performing tensile tests on an adequate number of laminations representative of the whole population. The present paper presents...... an investigation aimed at establishing such an adequate experimental background for the assignment of strength classes for glulam made of visually strength graded laminations from Nordic sawmills. The investigation includes more than 1800 boards (laminations) of Norway spruce (Picea abies) sampled from eight...

  5. Handbook for tensile properties of austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. W.; Ryu, W. S.; Jang, J. S.; Kim, S. H.; Kim, W. G.; Chung, M. K.; Han, C. H. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-03-01

    Database system of nuclear materials has not been developed and the physical and mechanical properties of materials used in nuclear power plant are not summarized systematically in Korea. Although Korea designs nuclear power plant, many materials used in nuclear power plant are imported because we do not have database system of nuclear material yet and it was hard to select a proper material for the structural materials of nuclear power plant. To develop database system of nuclear materials, data of mechanical, corrosion, irradiation properties are needed. Of theses properties, tensile properties are tested and summarized in this report. Tensile properties of stainless steel used in nuclear reactor internal were investigated. Data between Korea Atomic Energy Research Institute and foreign laboratory were compared to determine the precision of the result. To develope database system, materials, chemical composition, heat treatment, manufacturing process, and grain size were classified. Tensile properties were tested and summarized to use input data of database system. 9 figs., 9 tabs. (Author)

  6. Postirradiation tensile properties of Mo and Mo alloys irradiated with 600 MeV protons

    International Nuclear Information System (INIS)

    Mueller, G.V.; Gavillet, D.; Victoria, M.; Martin, J.L.

    1994-01-01

    Tensile specimens of pure Mo and Mo-5 Re, Mo-41 Re and TZM alloys have been irradiated with 600 MeV protons in the PIREX facility at 300 and 660 K to 0.5 dpa. Results of the postirradiation tensile testing show a strong radiation hardening and a severe loss of ductility for all the materials tested at room temperature. ((orig.))

  7. In vitro tensile strength of luting cements on metallic substrate.

    Science.gov (United States)

    Orsi, Iara A; Varoli, Fernando K; Pieroni, Carlos H P; Ferreira, Marly C C G; Borie, Eduardo

    2014-01-01

    The aim of this study was to determine the tensile strength of crowns cemented on metallic substrate with four different types of luting agents. Twenty human maxillary molars with similar diameters were selected and prepared to receive metallic core castings (Cu-Al). After cementation and preparation the cores were measured and the area of crown's portion was calculated. The teeth were divided into four groups based on the luting agent used to cement the crowns: zinc phosphate cement; glass ionomer cement; resin cement Rely X; and resin cement Panavia F. The teeth with the crowns cemented were subjected to thermocycling and later to the tensile strength test using universal testing machine with a load cell of 200 kgf and a crosshead speed of 0.5 mm/min. The load required to dislodge the crowns was recorded and converted to MPa/mm(2). Data were subjected to Kruskal-Wallis analysis with a significance level of 1%. Panavia F showed significantly higher retention in core casts (3.067 MPa/mm(2)), when compared with the other cements. Rely X showed a mean retention value of 1.877 MPa/mm(2) and the zinc phosphate cement with 1.155 MPa/mm(2). Glass ionomer cement (0.884 MPa/mm(2)) exhibited the lowest tensile strength value. Crowns cemented with Panavia F on cast metallic posts and cores presented higher tensile strength. The glass ionomer cement showed the lowest tensile strength among all the cements studied.

  8. EXPERIMENTAL INVESTIGATION ON TENSILE STRENGTH OF JACQUARD KNITTED FABRICS

    Directory of Open Access Journals (Sweden)

    BRAD Raluca

    2015-05-01

    Full Text Available An objective approach to select the best fabric for technical and home textiles consists in mechanical properties evaluation. The goal of this study is to analyze the behavior of knitted fabrics undergoing stretch stress. In this respect, three types of 2 colors Rib structure (backstripes jacquard, twillback jacquard and double-layered 3x3 rib fabric have been presented and tested for tensile strength and elongation on three directions. First, the elasticity and the behavior of knitted Rib fabrics were described The fabrics were knitted using 100% PAN yarns with Nm 1/15x2 on a E5 CMS 330 Stoll V-bed knitting machine, and have been tested using INSTROM 5587 Tensile Testing Machine in respect of standards conditions. After a relaxation period, 15 specimens were prepared, being disposed at 0°, 45 and 90 angles to the wale direction on the flat knitted panel. The tensile strength and the elongation values were recorded and mean values were computed. After strength and tensile elongation testing for 3 types of rib based knitted fabrics, one can see that the double layer knit presents the best mechanical behavior, followed by birds-eyebacking 2 colors Jacquard and then back striped Jacquard. For tensile stress in bias direction, the twillbacking Jacquard has a good breakage resistance value due to the higher number of rib sinker loops in structure that are positioned on the same direction with the tensile force. The twillbacking Jacquard structure could be considered as an alternative for the base material for decorative and home textile products.

  9. Comparison of uniaxial and triaxial accelerometry in the assessment of physical activity among adolescents under free-living conditions: the HELENA study

    Directory of Open Access Journals (Sweden)

    Vanhelst Jérémy

    2012-03-01

    Full Text Available Abstract Background Different types of devices are available and the choice about which to use depends on various factors: cost, physical characteristics, performance, and the validity and intra- and interinstrument reliability. Given the large number of studies that have used uniaxial or triaxial devices, it is of interest to know whether the different devices give similar information about PA levels and patterns. The aim of this study was to compare physical activity (PA levels and patterns obtained simultaneously by triaxial accelerometry and uniaxial accelerometry in adolescents in free-living conditions. Methods Sixty-two participants, aged 13-16 years, were recruited in this ancillary study, which is a part of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA. All participants wore a uniaxial accelerometer (ActiGraph GT1M®, Pensacola, FL and a triaxial accelerometer (RT3®, Stayhealthy, Monrovia, CA simultaneously for 7 days. The patterns were calculated by converting accelerometer data output as a percentage of time spent at sedentary, light, moderate, and vigorous PA per day. Analysis of output data from the two accelerometers were assessed by two different tests: Equivalence Test and Bland & Altman method. Results The concordance correlation coefficient between the data from the triaxial accelerometer and uniaxial accelerometer at each intensity level was superior to 0.95. The ANOVA test showed a significant difference for the first three lower intensities while no significant difference was found for vigorous intensity. The difference between data obtained with the triaxial accelerometer and the uniaxial monitor never exceeded 2.1% and decreased as PA level increased. The Bland & Altman method showed good agreement between data obtained between the both accelerometers (p Conclusions Uniaxial and triaxial accelerometers do not differ in their measurement of PA in population studies, and either could be used in such

  10. Volume growth during uniaxial tension of particle-filled elastomers at various temperatures - Experiments and modelling

    Science.gov (United States)

    Ilseng, Arne; Skallerud, Bjørn H.; Clausen, Arild H.

    2017-10-01

    A common presumption for elastomeric material behaviour is incompressibility, however, the inclusion of filler particles might give rise to matrix-particle decohesion and subsequent volume growth. In this article, the volumetric deformation accompanying uniaxial tension of particle-filled elastomeric materials at low temperatures is studied. An experimental set-up enabling full-field deformation measurements is outlined and novel data are reported on the significant volume growth accompanying uniaxial tension of two HNBR and one FKM compounds at temperatures of - 18 , 0, and 23 °C. The volumetric deformation was found to increase with reduced temperature for all compounds. To explain the observed dilatation, in situ scanning electron microscopy was used to inspect matrix-particle debonding occurring at the surface of the materials. A new constitutive model, combining the Bergström-Boyce visco-hyperelastic formulation with a Gurson flow potential function is outlined to account for the observed debonding effects in a numerical framework. The proposed model is shown to provide a good correspondence to the experimental data, including the volumetric response, for the tested FKM compound at all temperature levels.

  11. Atomistic simulations of the effect of embedded hydrogen and helium on the tensile properties of monocrystalline and nanocrystalline tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhe [Department of Physics, Beihang University, Beijing 100191 (China); Department of Mechanical Engineering, University of North Carolina at Charlotte, Charlotte, NC 28223-0001 (United States); Kecskes, Laszlo J. [US Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, MD 21005 (United States); Zhu, Kaigui, E-mail: kgzhu@buaa.edu.cn [Department of Physics, Beihang University, Beijing 100191 (China); Beijing Key Laboratory of Advanced Nuclear Energy Materials and Physics, Beihang University, Beijing 100191 (China); Wei, Qiuming, E-mail: qwei@uncc.edu [Department of Mechanical Engineering, University of North Carolina at Charlotte, Charlotte, NC 28223-0001 (United States)

    2016-12-01

    Uniaxial tensile properties of monocrystalline tungsten (MC-W) and nanocrystalline tungsten (NC-W) with embedded hydrogen and helium atoms have been investigated using molecular dynamics (MD) simulations in the context of radiation damage evolution. Different strain rates have been imposed to investigate the strain rate sensitivity (SRS) of the samples. Results show that the plastic deformation processes of MC-W and NC-W are dominated by different mechanisms, namely dislocation-based for MC-W and grain boundary-based activities for NC-W, respectively. For MC-W, the SRS increases and a transition appears in the deformation mechanism with increasing embedded atom concentration. However, no obvious embedded atom concentration dependence of the SRS has been observed for NC-W. Instead, in the latter case, the embedded atoms facilitate GB sliding and intergranular fracture. Additionally, a strong strain enhanced He cluster growth has been observed. The corresponding underlying mechanisms are discussed. - Highlights: • Uniaxial tensile behavior of monocrystal tungsten (C-W) and nanocrystalline W (NC-W) have been investigated. • Dislocation-based activities dominate the plastic deformation of MC-W. • Grain boundary-based activities dominate the plastic deformation of NC-W. • H/He atoms have significant impacts on the tensile behavior of MC-W and NC-W. • Strong strain enhanced He cluster growth has been revealed.

  12. Domain shape instabilities and dendrite domain growth in uniaxial ferroelectrics

    Science.gov (United States)

    Shur, Vladimir Ya.; Akhmatkhanov, Andrey R.

    2018-01-01

    The effects of domain wall shape instabilities and the formation of nanodomains in front of moving walls obtained in various uniaxial ferroelectrics are discussed. Special attention is paid to the formation of self-assembled nanoscale and dendrite domain structures under highly non-equilibrium switching conditions. All obtained results are considered in the framework of the unified kinetic approach to domain structure evolution based on the analogy with first-order phase transformation. This article is part of the theme issue `From atomistic interfaces to dendritic patterns'.

  13. Self-assembly of heterogeneous supramolecular structures with uniaxial anisotropy.

    Science.gov (United States)

    Ruiz-Osés, M; Gonzalez-Lakunza, N; Silanes, I; Gourdon, A; Arnau, A; Ortega, J E

    2006-12-28

    Uniaxial anisotropy in two-dimensional self-assembled supramolecular structures is achieved by the coadsorption of two different linear molecules with complementary amine and imide functionalization. The two-dimensional monolayer is defined by a one-dimensional stack of binary chains, which can be forced to line up along steps in vicinal surfaces. The competing driving forces in the self-organization process are discussed in light of the structures observed during single molecule adsorption and coadsorption on flat and vicinal surfaces and the corresponding theoretical calculations.

  14. Time Dependent and Steady Uni-axial Elongational Viscosity

    DEFF Research Database (Denmark)

    Nielsen, Jens K.; Rasmussen, Henrik Koblitz; Hassager, Ole

    2005-01-01

    Here we present measurements of transient and steady uni-axial elongational viscosity, using the Filament Stretching Rheometer1 or FSR1 (see Fig. 1) of the following melts: Four narrow MMD polystyrene (PS) samples with weight-average molar mass Mw in the range of 50k to 390k. Three different bi......-disperse samples, mixed from the narrow MMD PS. Two low-density polyethylene (LDPE) melts (Lupolen 1840D and 3020D). A steady-state viscosity was kept for 1-2.5 Hencky strain units in all measurements....

  15. Theoretical study of Cherenkov radiation emission in anisotropic uniaxial crystals

    Energy Technology Data Exchange (ETDEWEB)

    Delbart, A; Derre, J

    1996-04-01

    A theoretical review of the Cherenkov radiation emission in uniaxial crystals is presented. The formalism of C. Muzicar in terms of energetic properties of the emitted waves are corrected. This formalism is used to simulate the Cherenkov radiation emission in a strongly birefringent sodium nitrate crystal (NaNO{sub 3}) and to investigate the consequences of the slight anisotropy of sapphire (Al{sub 2}O{sub 3}) on the design of the Optical Trigger. (author). 12 refs. Submitted to Physical Review, D (US).

  16. Tensile and shear methods for measuring strength of bilayer tablets.

    Science.gov (United States)

    Chang, Shao-Yu; Li, Jian-Xin; Sun, Changquan Calvin

    2017-05-15

    Both shear and tensile measurement methods have been used to quantify interfacial bonding strength of bilayer tablets. The shear method is more convenient to perform, but reproducible strength data requires careful control of the placement of tablet and contact point for shear force application. Moreover, data obtained from the shear method depend on the orientation of the bilayer tablet. Although more time-consuming to perform, the tensile method yields data that are straightforward to interpret. Thus, the tensile method is preferred in fundamental bilayer tableting research to minimize ambiguity in data interpretation. Using both shear and tensile methods, we measured the mechanical strength of bilayer tablets made of several different layer combinations of lactose and microcrystalline cellulose. We observed a good correlation between strength obtained by the tensile method and carefully conducted shear method. This suggests that the shear method may be used for routine quality test of bilayer tablets during manufacturing because of its speed and convenience, provided a protocol for careful control of the placement of the tablet interface, tablet orientation, and blade is implemented. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. A Prediction Method of Tensile Young's Modulus of Concrete at Early Age

    Directory of Open Access Journals (Sweden)

    Isamu Yoshitake

    2012-01-01

    Full Text Available Knowledge of the tensile Young's modulus of concrete at early ages is important for estimating the risk of cracking due to restrained shrinkage and thermal contraction. However, most often, the tensile modulus is considered equal to the compressive modulus and is estimated empirically based on the measurements of compressive strength. To evaluate the validity of this approach, the tensile Young's moduli of 6 concrete and mortar mixtures are measured using a direct tension test. The results show that the tensile moduli are approximately 1.0–1.3-times larger than the compressive moduli within the material's first week of age. To enable a direct estimation of the tensile modulus of concrete, a simple three-phase composite model is developed based on random distributions of coarse aggregate, mortar, and air void phases. The model predictions show good agreement with experimental measurements of tensile modulus at early age.

  18. Analysis/design of tensile property database system

    International Nuclear Information System (INIS)

    Park, S. J.; Kim, D. H.; Jeon, I.; Lyu, W. S.

    2001-01-01

    The data base construction using the data produced from tensile experiment can increase the application of test results. Also, we can get the basic data ease from database when we prepare the new experiment and can produce high quality result by compare the previous data. The development part must be analysis and design more specific to construct the database and after that, we can offer the best quality to customers various requirements. In this thesis, the analysis and design was performed to develop the database for tensile extension property

  19. Tensile, swelling and morphological properties of bentonite-filled acrylonitrile butadiene rubber composites

    Science.gov (United States)

    Lotfi, Muhamad Nadhli Amin; Ismail, Hanafi; Othman, Nadras

    2017-10-01

    Tensile, swelling and morphological properties of bentonite filled acrylonitrile butadiene rubber (NBR/Bt) composites were studied. The experiments were conducted at room temperature by using two rolled mill, universal testing machine (INSTRON), and American Standard Testing Method (ASTM) D471 for compounding, tensile testing, and swelling test, respectively. Results obtained indicated that a better tensile strength, elongation at break and tensile modulus were recorded as compared to the pure NBR particularly up to 90 phr of Bt loading. However, swelling (%) exhibited the opposite trend where the liquid uptake by the composites was indirectly proportional with the increasing of Bt loading. Scanning electron microscopy (SEM) used on the tensile fractured surface of the NBR/Bt composites have shown that the fillers were well embedded in the NBR matrix, for Bt loading up to 90 phr. The agglomeration of fillers occurred for Bt loading exceeding 90 phr.

  20. Tensile Strength of Finger Joints at Elevated Temperatures

    DEFF Research Database (Denmark)

    Nielsen, Peter C.; Olesen, Frits Bolonius

    A series of test s aimed a t establishing the effect of temperature upon the tensile strength parallel-to-grain of finger jointed laminae for glulam has been conducted in the Fire Research Laboratory at Aalborg University Centre. The objective of this report is to present the background...

  1. Micro-tensile strength of a welded turbine disc superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Oluwasegun, K.M.; Cooper, C.; Chiu, Y.L.; Jones, I.P. [School of Metallurgy and Materials, University of Birmingham, B15 2TT (United Kingdom); Li, H.Y., E-mail: h.y.li.1@bham.ac.uk [School of Metallurgy and Materials, University of Birmingham, B15 2TT (United Kingdom); Baxter, G. [Rolls-Royce plc., P.O. Box 31, Derby DE24 8BJ (United Kingdom)

    2014-02-24

    A micro-tensile testing system coupled with focussed ion beam (FIB) machining was used to characterise the micro-mechanical properties of the weld from a turbine disc alloy. The strength variations between the weld and the base alloy are rationalised via the microstructure obtained.

  2. Strain distribution during tensile deformation of nanostructured aluminum samples

    DEFF Research Database (Denmark)

    Kidmose, Jacob; Lu, L.; Winther, Grethe

    2012-01-01

    To optimize the mechanical properties, especially formability, post-process deformation by cold rolling in the range 5–50 % reduction was applied to aluminum sheets produced by accumulative roll bonding to an equivalent strain of 4.8. During tensile testing high resolution maps of the strain...

  3. Statistical behavior of the tensile property of heated cotton fiber

    Science.gov (United States)

    The temperature dependence of the tensile property of single cotton fiber was studied in the range of 160-300°C using Favimat test, and its statistical behavior was interpreted in terms of structural changes. The tenacity of control cotton fiber was well described by the single Weibull distribution,...

  4. Tensile and creep data on type 316 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V. K.; Booker, B. L.P.; Booker, M. K.; McEnerney, J. W.

    1980-01-01

    This report summarizes tensile and creep data on 13 heats of type 316 stainless steel. It includes ten different product forms (three plates, four pipes, and three bars) of the reference heat tested at ORNL. Tensile data are presented in tabular form and analyzed as a function of temperature by the heat centering method. This method yielded a measure of variations within a single heat as well as among different heats. The upper and lower scatter bands developed by this method were wider at the lower temperatures than at the high temperatures (for strength properties), a trend reflected by the experimental data. The creep data on both unaged and aged specimens are presented in tabular form along with creep curves for each test. The rupture time data are compared with the ASME Code Case minimum curve at each test temperature in the range from 538 to 704{sup 0}C. The experimental rupture time data are also compared with the values predicted by using the rupture model based on elevated-temperature ultimate tensile strength. A creep ductility trend curve was developed on the basis of the reference heat data and those published in the literature on nitrogen effects. To characterize the data fully, information was also supplied on vendor, product form, fabrication method, material condition (mill-annealed vs laboratory annealed and aged), grain size, and chemical composition for various heats. Test procedures used for tensile and creep results are also discussed.

  5. High-temperature mechanical properties of a uniaxially reinforced zircon-silicon carbide composite

    International Nuclear Information System (INIS)

    Singh, R.N.

    1990-01-01

    This paper reports that mechanical properties of a monolithic zircon ceramic and zircon-matrix composites uniaxially reinforced with either uncoated or BN-coated silicon carbide monofilaments were measured in flexure between 25 degrees and 1477 degrees C. Monolithic zircon ceramics were weak and exhibited a brittle failure up to abut 1300 degrees C. An increasing amount of the plastic deformation was observed before failure above about 1300 degrees C. In contrast, composites reinforced with either uncoated or BN-coated Sic filaments were stronger and tougher than the monolithic zircon at all test temperatures between 25 degrees and 1477 degrees. The ultimate strength and work-of-fracture of composite samples decreased with increasing temperature. A transgranular matrix fracture was shown by the monolithic and composite samples tested up to about 1200 degrees C, whereas an increasing amount of the intergranular matrix fracture was displayed above 1200 degrees C

  6. Raman study of lead zirconate titanate under uniaxial stress

    International Nuclear Information System (INIS)

    Tallant, David R.; Simpson, Regina L.; Grazier, J. Mark; Zeuch, David H.; Olson, Walter R.; Tuttle, Bruce A.

    2000-01-01

    The authors used micro-Raman spectroscopy to monitor the ferroelectric (FE) to antiferroelectric (AFE) phase transition in PZT ceramic bars during the application of uniaxial stress. They designed and constructed a simple loading device, which can apply sufficient uniaxial force to transform reasonably large ceramic bars while being small enough to fit on the mechanical stage of the microscope used for Raman analysis. Raman spectra of individual grains in ceramic PZT bars were obtained as the stress on the bar was increased in increments. At the same time gauges attached to the PZT bar recorded axial and lateral strains induced by the applied stress. The Raman spectra were used to calculate an FE coordinate, which is related to the fraction of FE phase present. The authors present data showing changes in the FE coordinates of individual PZT grains and correlate these changes to stress-strain data, which plot the macroscopic evolution of the FE-to-AFE transformation. Their data indicates that the FE-to-AFE transformation does not occur simultaneously for all PZT grains but that grains react individually to local conditions

  7. Effect of Second Phase Particles on the Tensile Instability of a Nanostructured Al-1%Si Alloy

    DEFF Research Database (Denmark)

    Huang, Tian Lin; Wu, Gui Lin; Liu, Qing

    2014-01-01

    A nanostructured Al-1%Si alloy containing dispersed Si particles was produced by heavily cold-rolling to study the effect of second phase particles on the tensile instability of nanostructured metals. Tensile tests were conducted on the as-deformed sample and the samples after recovery annealing ...

  8. LPTR irradiation of LLL vanadium tensile specimens and LLL Nb--1Zr tensile specimens

    International Nuclear Information System (INIS)

    MacLean, S.C.; Rowe, C.L.

    1977-01-01

    The LPTR irradiation of 14 LLL vanadium tensile specimens and 14 LLL Nb-1Zr tensile specimens is described. Sample packaging, the irradiation schedule and neutron fluences for three energy ranges are given

  9. Effect of Root Moisture Content and Diameter on Root Tensile Properties

    Science.gov (United States)

    Yang, Yuanjun; Chen, Lihua; Li, Ning; Zhang, Qiufen

    2016-01-01

    The stabilization of slopes by vegetation has been a topical issue for many years. Root mechanical characteristics significantly influence soil reinforcement; therefore it is necessary to research into the indicators of root tensile properties. In this study, we explored the influence of root moisture content on tensile resistance and strength with different root diameters and for different tree species. Betula platyphylla, Quercus mongolica, Pinus tabulaeformis, and Larix gmelinii, the most popular tree species used for slope stabilization in the rocky mountainous areas of northern China, were used in this study. A tensile test was conducted after root samples were grouped by diameter and moisture content. The results showedthat:1) root moisture content had a significant influence on tensile properties; 2) slightly loss of root moisture content could enhance tensile strength, but too much loss of water resulted in weaker capacity for root elongation, and consequently reduced tensile strength; 3) root diameter had a strong positive correlation with tensile resistance; and4) the roots of Betula platyphylla had the best tensile properties when both diameter and moisture content being controlled. These findings improve our understanding of root tensile properties with root size and moisture, and could be useful for slope stabilization using vegetation. PMID:27003872

  10. Dynamic rock tensile strengths of Laurentian granite: Experimental observation and micromechanical model

    Directory of Open Access Journals (Sweden)

    Kaiwen Xia

    2017-02-01

    Full Text Available Tensile strength is an important material property for rocks. In applications where rocks are subjected to dynamic loads, the dynamic tensile strength is the controlling parameter. Similar to the study of static tensile strength, there are various methods proposed to measure the dynamic tensile strength of rocks. Here we examine dynamic tensile strength values of Laurentian granite (LG measured from three methods: dynamic direct tension, dynamic Brazilian disc (BD test, and dynamic semi-circular bending (SCB. We found that the dynamic tensile strength from direct tension has the lowest value, and the dynamic SCB gives the highest strength at a given loading rate. Because the dynamic direct tension measures the intrinsic rock tensile strength, it is thus necessary to reconcile the differences in strength values between the direct tension and the other two methods. We attribute the difference between the dynamic BD results and the direct tension results to the overload and internal friction in BD tests. The difference between the dynamic SCB results and the direct tension results can be understood by invoking the non-local failure theory. It is shown that, after appropriate corrections, the dynamic tensile strengths from the two other tests can be reduced to those from direct tension.

  11. Tensile characterisation of the aorta across quasi-static to blast loading strain rates

    Science.gov (United States)

    Magnus, Danyal; Proud, William; Haller, Antoine; Jouffroy, Apolline

    2017-06-01

    The dynamic tensile failure mechanisms of the aorta during Traumatic Aortic Injury (TAI) are poorly understood. In automotive incidents, where the aorta may be under strains of the order of 100/s, TAI is the second largest cause of mortality. In these studies, the proximal descending aorta is the most common site where rupture is observed. In particular, the transverse direction is most commonly affected due to the circumferential orientation of elastin, and hence the literature generally concentrates upon axial samples. This project extends these dynamic studies to the blast loading regime where strain-rates are of the order of 1000/s. A campaign of uniaxial tensile experiments are conducted at quasi-static, intermediate (drop-weight) and high (tensile Split-Hopkinson Pressure Bar) strain rates. In each case, murine and porcine aorta models are considered and the extent of damage assessed post-loading using histology. Experimental data will be compared against current viscoelastic models of the aorta under axial stress. Their applicability across strain rates will be discussed. Using a multi-disciplinary approach, the conditions applied to the samples replicate in vivo conditions, employing a blood simulant-filled tubular specimen surrounded by a physiological solution.

  12. Effect of chain extension on rheology and tensile properties of PHB and PHB-PLA blends

    Science.gov (United States)

    Bousfield, Glenn

    blend continued to degrade, and the PLLA did not in these cases significantly increase complex viscosity. By contrast, the 25/75 PHB/PLLA blend had a complex viscosity equal to the neat PLLA blend, and both of the blends remained stable. All five blends were also produced with 1% Joncryl to observe the effect of Joncryl on the blends. In the 50/50 blend and the blends in which PLLA was the major component, complex viscosity increased by at least an order of magnitude, while in the 75/25 PHB/PLLA blend and the neat PHB blend, the effect of Joncryl was to increase complex viscosity only by a factor of 2. The effect of blending and of Joncryl on PHB-PLA blends was further investigated through uniaxial tensile stress testing of compression moulded samples of the blends, neat and with 1% Joncryl. The results showed an increase in tensile stress at yield and tensile strain at break for blends with the addition of Joncryl, although Young's modulus was somewhat diminished for these blends. In conclusion, chain extenders were not effective in reversing the effect of thermomechanical degradation, possibly because they do not change the resistance to bond rotation in PHB chains, or because they are not reactive with acrylates, although the exact cause has not been determined.

  13. Porosity Defect Remodeling and Tensile Analysis of Cast Steel

    Directory of Open Access Journals (Sweden)

    Linfeng Sun

    2016-02-01

    Full Text Available Tensile properties on ASTM A216 WCB cast steel with centerline porosity defect were studied with radiographic mapping and finite element remodeling technique. Non-linear elastic and plastic behaviors dependent on porosity were mathematically described by relevant equation sets. According to the ASTM E8 tensile test standard, matrix and defect specimens were machined into two categories by two types of height. After applying radiographic inspection, defect morphologies were mapped to the mid-sections of the finite element models and the porosity fraction fields had been generated with interpolation method. ABAQUS input parameters were confirmed by trial simulations to the matrix specimen and comparison with experimental outcomes. Fine agreements of the result curves between simulations and experiments could be observed, and predicted positions of the tensile fracture were found to be in accordance with the tests. Chord modulus was used to obtain the equivalent elastic stiffness because of the non-linear features. The results showed that elongation was the most influenced term to the defect cast steel, compared with elastic stiffness and yield stress. Additional visual explanations on the tensile fracture caused by void propagation were also given by the result contours at different mechanical stages, including distributions of Mises stress and plastic strain.

  14. Tensile Strength of GFRP Reinforcing Bars with Hollow Section

    Directory of Open Access Journals (Sweden)

    Young-Jun You

    2015-01-01

    Full Text Available Fiber reinforced polymer (FRP has been proposed to replace steel as a reinforcing bar (rebar due to its high tensile strength and noncorrosive material properties. One obstacle in using FRP rebars is high price. Generally FRP is more expensive than conventional steel rebar. There are mainly two ways to reduce the cost. For example, one is making the price of each composition cost of FRP rebar (e.g., fibers, resin, etc. lower than steel rebar. Another is making an optimized design for cross section and reducing the material cost. The former approach is not easy because the steel price is very low in comparison with component materials of FRP. For the latter approach, the cost could be cut down by reducing the material cost. Therefore, an idea of making hollow section over the cross section of FRP rebar was proposed in this study by optimizing the cross section design with acceptable tensile performance in comparison with steel rebar. In this study, glass reinforced polymer (GFRP rebars with hollow section and 19 mm of outer diameter were manufactured and tested to evaluate the tensile performance in accordance with the hollowness ratio. From the test results, it was observed that the tensile strength decreased almost linearly with increase of hollowness ratio and the elastic modulus decreased nonlinearly.

  15. Tensile Characterization of FRP Rods for Reinforced Concrete Structures

    Science.gov (United States)

    Micelli, F.; Nanni, A.

    2003-07-01

    The application of FRP rods as an internal or external reinforcement in new or damaged concrete structures is based on the development of design equations that take into account the mechanical properties of FRP material systems.The measurement of mechanical characteristics of FRP requires a special anchoring and protocol, since it is well known that these characteristics depend on the direction and content of fibers. In this study, an effective tensile test method is described for the mechanical characterization of FRP rods. Twelve types of glass and carbon FRP specimens with different sizes and surface characteristics were tested to validate the procedure proposed. In all, 79 tensile tests were performed, and the results obtained are discussed in this paper. Recommendations are given for specimen preparation and test setup in order to facilitate the further investigation and standardization of the FRP rods used in civil engineering.

  16. Ultimate uniaxial compressive strength of stiffened panel with opening under lateral pressure

    Directory of Open Access Journals (Sweden)

    Chang-Li Yu

    2015-03-01

    Full Text Available This paper concentrated on the ultimate uniaxial compressive strength of stiffened panel with opening under lateral load and also studied the design-oriented formulae. For this purpose, three series of well executed experiments on longitudinal stiffened panel with rectangular opening subjected to the combined load have been selected as test models. The finite element analysis package, ABAQUS, is used for simulation with considering the large elasticplastic deflection behavior of stiffened panels. The feasibility of the numerical procedure is verified by a good agreement of experimental results and numerical results. More cases studies are executed employing nonlinear finite element method to analyze the influence of design variables on the ultimate strength of stiffened panel with opening under combined pressure. Based on data, two design formulae corresponding to different opening types are fitted, and accuracy of them is illustrated to demonstrate that they could be applied to basic design of practical engineering structure.

  17. Compressive Properties of PTFE/Al/Ni Composite Under Uniaxial Loading

    Science.gov (United States)

    Wang, Huai-xi; Li, Yu-chun; Feng, Bin; Huang, Jun-yi; Zhang, Sheng; Fang, Xiang

    2017-05-01

    To investigate the mechanical properties of pressed and sintered PTFE/Al/Ni (polytetrafluoroethylene/aluminum/nickel) composite, uniaxial quasi-static and dynamic compression experiments were conducted at strain rates from 10-2 to 3 × 103/s. The prepared samples were tested by an electrohydraulic press with 300 kN loading capacity and a split Hopkinson pressure bar (SHPB) device at room temperature. Experimental results show that PTFE/Al/Ni composite exhibits evident strain hardening and strain rate hardening. Additionally, a bilinear relationship between stress and {{log(}}\\dot{ɛ} ) is observed. The experimental data were fit to Johnson-Cook constitutive model, and the results are in well agreement with measured data.

  18. Effect of uniaxially pressing ordinary Portland cement pastes containing metal hydroxides on porosity, density, and leaching

    International Nuclear Information System (INIS)

    Cheeseman, C.R.; Asavapisit, S.; Knight, J.

    1998-01-01

    Synthetic metal hydroxide wastes containing Zn and Pb have been mixed with partially hydrated cement and uniaxially pressed. The effect on porosity, pore size distribution, and bulk and skeletal densities has been characterized using mercury intrusion porosimetry. Ca(OH) 2 formation has been determined using differential thermal analysis and metal leaching has been assessed in a series of static leach tests completed on monolithic samples. Pressed solidified materials have increased density, reduced porosity, and reduced Ca(OH) 2 . They exhibit increased resistance to acid attack in terms of sample weight loss during leaching due to reduced release of alkalis. Leaching of Zn and Pb is primarily determined by pH. A peak observed in Zn leaching from pressed samples is due to the effect of changing leachate pH on the dominant Zn species present

  19. Tensile behavior of humid aged advanced composites for helicopter external fuel tank development

    Directory of Open Access Journals (Sweden)

    Condruz Mihaela

    2018-01-01

    Full Text Available Influence of humid aging on tensile properties of two polymeric composites was studied. The purpose of the study was to evaluate the suitability of the materials for a naval helicopter external fuel tank. Due to the application, the humid environment was kerosene and saline solution to evaluate the sea water effect on the composite tensile strength. The composite samples were immersed in kerosene for 168 hours, respective 1752 hours and in saline solution for 168 hours. Tensile tests were performed after the immersion. The composite sample tensile tests showed that kerosene and saline solution had no influence on the elastic modulus of the materials, but it was observed a slight improvement of the tensile strength of the two polymeric composites.

  20. A combined experimental and FE analysis procedure to evaluate tensile behavior of zircaloy pressure tubes

    International Nuclear Information System (INIS)

    Samal, M.K.; Vaze, K.K.; Balakrishnan, K.S.; Anantharaman, S.

    2012-01-01

    Determination of transverse mechanical properties from the ring type of specimens directly machined from the nuclear reactor pressure tubes is not straightforward because of the presence of combined membrane as well as bending stresses arising in the loaded condition. In this work, we have performed ring-tensile tests on the un-irradiated ring tensile specimen using two split semi-cylindrical mandrels as the loading device. A 3-D finite element (FE) analysis was performed in order to determine the material true stress-strain curve by comparing experimental load-displacement data with those predicted by FE analysis. In order to validate the methodology, miniaturized tensile specimens were machined from these tubes and tested. It was observed that the stress-strain data as obtained from ring tensile specimen could describe the load displacement curve of the miniaturized flat tensile specimen very well. (author)

  1. Tensile properties of interwoven hemp/PET (Polyethylene Terephthalate) epoxy hybrid composites

    Science.gov (United States)

    Ahmad, M. A. A.; Majid, M. S. A.; Ridzuan, M. J. M.; Firdaus, A. Z. A.; Amin, N. A. M.

    2017-10-01

    This paper describes the experimental investigation of the tensile properties of interwoven Hemp/PET hybrid composites. The effect of hybridization of hemp (warp) with PET fibres (weft) on tensile properties was of interest. Hemp and PET fibres were selected as the reinforcing material while epoxy resin was chosen as the matrix. The interwoven Hemp/PET fabric was used to produce hybrid composite using a vacuum infusion process. The tensile test was conducted using Universal Testing Machine in accordance to the ASTM D638. The tensile properties of the interwoven Hemp/PET hybrid composite were then compared with the neat woven hemp/epoxy composite. The results show that the strength of hemp/PET with the warp direction was increased by 8% compared to the neat woven hemp composite. This enhancement of tensile strength was due to the improved interlocking structure of interwoven Hemp/PET hybrid fabric.

  2. The Statistical Analysis of Relation between Compressive and Tensile/Flexural Strength of High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Kępniak M.

    2016-12-01

    Full Text Available This paper addresses the tensile and flexural strength of HPC (high performance concrete. The aim of the paper is to analyse the efficiency of models proposed in different codes. In particular, three design procedures from: the ACI 318 [1], Eurocode 2 [2] and the Model Code 2010 [3] are considered. The associations between design tensile strength of concrete obtained from these three codes and compressive strength are compared with experimental results of tensile strength and flexural strength by statistical tools. Experimental results of tensile strength were obtained in the splitting test. Based on this comparison, conclusions are drawn according to the fit between the design methods and the test data. The comparison shows that tensile strength and flexural strength of HPC depend on more influential factors and not only compressive strength.

  3. Ultra-high temperature tensile properties of ODS steel claddings under severe accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Y., E-mail: yano.yasuhide@jaea.go.jp [Japan Atomic Energy Agency, 4002, Narita-cho, Oarai-machi, Ibaraki, 311-1393 (Japan); Tanno, T.; Oka, H.; Ohtsuka, S.; Inoue, T.; Kato, S.; Furukawa, T.; Uwaba, T.; Kaito, T. [Japan Atomic Energy Agency, 4002, Narita-cho, Oarai-machi, Ibaraki, 311-1393 (Japan); Ukai, S.; Oono, N. [Materials Science and Engineering, Faculty of Engineering, Hokkaido University, N13, W-8, Kita-ku, Sapporo, Hokkaido, 060-8628 (Japan); Kimura, A. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Hayashi, S. [Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Torimaru, T. [Nippon Nuclear Fuel Development Co., Ltd., 2163, Narita-cho, Oarai-machi, Ibaraki, 311-1313 (Japan)

    2017-04-15

    Ultra-high temperature ring tensile tests were performed to investigate the tensile behavior of oxide dispersion strengthened (ODS) steel claddings and wrapper materials under severe accident conditions with temperatures ranging from room temperature to 1400 °C which is close to the melting point of core materials. The experimental results showed that the tensile strength of 9Cr-ODS steel claddings was highest in the core materials at ultra-high temperatures of 900–1200 °C, but there was significant degradation in the tensile strength of 9Cr-ODS steel claddings above 1200 °C. This degradation was attributed to grain boundary sliding deformation with γ/δ transformation, which is associated with reduced ductility. By contrast, the tensile strength of recrystallized 12Cr-ODS and FeCrAl-ODS steel claddings retained its high value above 1200 °C, unlike the other tested materials.

  4. Ultra-high temperature tensile properties of ODS steel claddings under severe accident conditions

    Science.gov (United States)

    Yano, Y.; Tanno, T.; Oka, H.; Ohtsuka, S.; Inoue, T.; Kato, S.; Furukawa, T.; Uwaba, T.; Kaito, T.; Ukai, S.; Oono, N.; Kimura, A.; Hayashi, S.; Torimaru, T.

    2017-04-01

    Ultra-high temperature ring tensile tests were performed to investigate the tensile behavior of oxide dispersion strengthened (ODS) steel claddings and wrapper materials under severe accident conditions with temperatures ranging from room temperature to 1400 °C which is close to the melting point of core materials. The experimental results showed that the tensile strength of 9Cr-ODS steel claddings was highest in the core materials at ultra-high temperatures of 900-1200 °C, but there was significant degradation in the tensile strength of 9Cr-ODS steel claddings above 1200 °C. This degradation was attributed to grain boundary sliding deformation with γ/δ transformation, which is associated with reduced ductility. By contrast, the tensile strength of recrystallized 12Cr-ODS and FeCrAl-ODS steel claddings retained its high value above 1200 °C, unlike the other tested materials.

  5. Fabrication and morphology of uniaxially aligned perylenediimide nanowires

    Science.gov (United States)

    Machida, Shinjiro; Tanikatsu, Makoto; Itaya, Akira; Ikeda, Noriaki

    2017-06-01

    Uniaxial alignment of crystalline nanowires consisting of N,N‧-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) was achieved on poly(tetrafluoroethylene) (PTFE) layers prepared by friction transfer method on a glass substrate. The nanowires were formed by spin-coating a trifluoroacetic acid (TFA) solution of PTCDI-C8 on the PTFE layers and were further grown under TFA vapor atmosphere. The morphology of the PTCDI-C8 nanowires were characterized using atomic force microscope (AFM) and fluorescence optical microscope with changing the dye concentration in the spin coating solution, annealing time in the TFA vapor, and substrate materials. The nanowires prepared on the PTFE layer on a silica-coated silicon or a mica substrate did not grow so well as those on the glass substrate. This result suggests that the surface roughness would affect the PTFE layer and the growth of the PTCDI nanowires.

  6. Surface Wave Velocity-Stress Relationship in Uniaxially Loaded Concrete

    DEFF Research Database (Denmark)

    Shokouhi, Parisa; Zoëga, Andreas; Wiggenhauser, Herbert

    2012-01-01

    The sonic surface wave (or Rayleigh wave) velocity measured on prismatic concrete specimens under uniaxial compression was found to be highly stress-dependent. At low stress levels, the acoustoelastic effect and the closure of existing microcracks results in a gradual increase in surface wave...... velocities. At higher stress levels, concrete suffers irrecoverable damage: the existing microcracks widen and coalesce and new microcracks form. This progressive damage process leads first to the flattening and eventually the drop in the velocity-stress curves. Measurements on specimens undergoing several...... loading cycles revealed that the velocities show a stress-memory effect in good agreement with the Kaiser effect. Comparing the velocities measured during loading and unloading, the effects of stress and damage on the measured velocities could be differentiated. Moreover, the stress dependency of surface...

  7. Uniaxially aligned ceramic nanofibers obtained by chemical mechanical processing

    Energy Technology Data Exchange (ETDEWEB)

    Tararam, R. [Univ Estadual Paulista – UNESP – Instituto de Química, Rua Prof. Francisco Degni n° 55, CEP 14800-900 Araraquara, SP (Brazil); Foschini, C.R. [Univ Estadual Paulista – UNESP – Faculdade de Engenharia de Bauru, Dept. de Eng. Mecanica, Av. Eng. Luiz Edmundo C. Coube 14-01, CEP 17033-360 Bauru, SP (Brazil); Destro, F.B. [Univ Estadual Paulista – UNESP – Faculdade de Engenharia de Guaratinguetá, Guaratinguetá 12516-410, SP (Brazil); Simões, A.Z., E-mail: alezipo@yahoo.com [Univ Estadual Paulista – UNESP – Faculdade de Engenharia de Guaratinguetá, Guaratinguetá 12516-410, SP (Brazil); Longo, E.; Varela, J.A. [Univ Estadual Paulista – UNESP – Instituto de Química, Rua Prof. Francisco Degni n° 55, CEP 14800-900 Araraquara, SP (Brazil)

    2014-08-01

    For this study, we investigated a simple method to generate well aligned nanofibers over large areas using an organic polymer stretched over the substrate surface With this method, ZnO and CuO 3D parallel nanowire arrays were successfully prepared by calcinations of the polymer fibers. X-ray diffraction (XRD) analysis revealed that the copper oxide has a monoclinic structure while the zinc oxide has a hexagonal structure. Scanning electron microscopy (SEM) analysis showed ceramic nanofibers with an average diameter of 120 nm which were composed of small nanoparticles which are 10 nm in diameter. The ability to obtain uniaxially aligned nanofibers reveals a range of interesting properties with potential applications for sensors, catalysts and energy technologies.

  8. Dynamic hysteresis of a uniaxial superparamagnet: Semi-adiabatic approximation

    International Nuclear Information System (INIS)

    Poperechny, I.S.; Raikher, Yu.L.; Stepanov, V.I.

    2014-01-01

    The semi-adiabatic theory of magnetic response of a uniaxial single-domain ferromagnetic particle is presented. The approach is developed in the context of the kinetic theory and allows for any orientation of the external field. Within this approximation, the dynamic magnetic hysteresis loops in an ac field are calculated. It is demonstrated that they very closely resemble those obtained by the full kinetic theory. The behavior of the effective coercive force is analyzed in detail, and for it a simple formula is proposed. This relation accounts not only for the temperature behavior of the coercive force, as the previous ones do, but also yields the dependence on the frequency and amplitude of the applied field

  9. Uniaxial Compressive Strengths of Rocks Drilled at Gale Crater, Mars

    Science.gov (United States)

    Peters, G. H.; Carey, E. M.; Anderson, R. C.; Abbey, W. J.; Kinnett, R.; Watkins, J. A.; Schemel, M.; Lashore, M. O.; Chasek, M. D.; Green, W.; Beegle, L. W.; Vasavada, A. R.

    2018-01-01

    Measuring the physical properties of geological materials is important for understanding geologic history. Yet there has never been an instrument with the purpose of measuring mechanical properties of rocks sent to another planet. The Mars Science Laboratory (MSL) rover employs the Powder Acquisition Drill System (PADS), which provides direct mechanical interaction with Martian outcrops. While the objective of the drill system is not to make scientific measurements, the drill's performance is directly influenced by the mechanical properties of the rocks it drills into. We have developed a methodology that uses the drill to indicate the uniaxial compressive strengths of rocks through comparison with performance of an identically assembled drill system in terrestrial samples of comparable sedimentary class. During this investigation, we utilize engineering data collected on Mars to calculate the percussive energy needed to maintain a prescribed rate of penetration and correlate that to rock strength.

  10. Nonparaxial propagation of Lorentz-Gauss beams in uniaxial crystal orthogonal to the optical axis.

    Science.gov (United States)

    Wang, Xun; Liu, Zhirong; Zhao, Daomu

    2014-04-01

    Analytical expressions for the three components of nonparaxial propagation of a polarized Lorentz-Gauss beam in uniaxial crystal orthogonal to the optical axis are derived and used to investigate its propagation properties in uniaxial crystal. The influences of the initial beam parameters and the parameters of the uniaxial crystal on the evolution of the beam-intensity distribution in the uniaxial crystal are examined in detail. Results show that the statistical properties of a nonparaxial Lorentz-Gauss beam in a uniaxial crystal orthogonal to the optical axis are closely determined by the initial beam's parameters and the parameters of the crystal: the beam waist sizes-w(0), w(0x), and w(0y)-not only affect the size and shape of the beam profile in uniaxial crystal but also determine the nonparaxial effect of a Lorentz-Gauss beam; the beam profile of a Lorentz-Gauss beam in uniaxial crystal is elongated in the x or y direction, which is determined by the ratio of the extraordinary refractive index to the ordinary refractive index; with increasing deviation of the ratio from unity, the extension of the beam profile augments. The results indicate that uniaxial crystal provides an effective and convenient method for modulating the Lorentz-Gauss beams. Our results may be valuable in some fields, such as optical trapping and nonlinear optics, where a light beam with a special profile and polarization is required.

  11. An atomic resolution scanning tunneling microscope that applies external tensile stress and strain in an ultrahigh vacuum

    International Nuclear Information System (INIS)

    Fujita, D; Kitahara, M; Onishi, K; Sagisaka, K

    2008-01-01

    We have developed an ultrahigh vacuum scanning tunneling microscope with an in situ external stress application capability in order to determine the effects of stress and strain on surface atomistic structures. It is necessary to understand these effects because controlling them will be a key technology that will very likely be used in future nanometer-scale fabrication processes. We used our microscope to demonstrate atomic resolution imaging under external tensile stress and strain on the surfaces of wafers of Si(111) and Si(001). We also successfully observed domain redistribution induced by applying uniaxial stress at an elevated temperature on the surface of a wafer of vicinal Si(100). We confirmed that domains for which an applied tensile stress is directed along the dimer bond become less stable and shrink. This suggests that it may be feasible to fabricate single domain surfaces in a process that controls surface stress and strain

  12. Effect of N+Cr alloying on the microstructures and tensile properties of Hadfield steel

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Zhang, F.C., E-mail: zfc@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); National Engineering Research Center for Equipment and Technology of Cold Strip Rolling, Yanshan University, Qinhuangdao 066004 (China); Wang, F. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Liu, H.; Yu, B.D. [China Railway Shanhaiguan Bridge Group Co. LTD, Qinhuangdao 066205 (China)

    2017-01-02

    The microstructures and tensile behaviors of traditional Hadfield steel, named Mn12 steel, and Hadfield steel alloyed with N+Cr, named Mn12CrN steel were studied through optical microscopy, transmission electron microscopy, and scanning electron microscopy, among others. Three different tensile strain rates of 5×10{sup −4}, 5×10{sup −3}, and 5×10{sup −2} s{sup −1} were selected in the tensile test. The deformation microstructures and fracture morphologies of the two steels after fracture in the tensile test were observed to analyze the tensile deformation response to different tensile strain rates. Results showed that the grain size of Mn12CrN steel was evidently refined after alloying with N+Cr. The grain would not become abnormally coarse even with increasing austenitizing temperature. During tensile deformation, the strength and plasticity of Mn12CrN steel were superior to those of Mn12 steel at the same strain rate. With increasing the strain rate, the changes in strength and plasticity of Mn12CrN steel were less sensitive to tensile strain rate compared with Mn12 steel. The effects of grain refinement and N+Cr alloying on dynamic strain aging and deformation twining behaviors were responsible for this lack of sensitivity to strain rate.

  13. Effect of N+Cr alloying on the microstructures and tensile properties of Hadfield steel

    International Nuclear Information System (INIS)

    Chen, C.; Zhang, F.C.; Wang, F.; Liu, H.; Yu, B.D.

    2017-01-01

    The microstructures and tensile behaviors of traditional Hadfield steel, named Mn12 steel, and Hadfield steel alloyed with N+Cr, named Mn12CrN steel were studied through optical microscopy, transmission electron microscopy, and scanning electron microscopy, among others. Three different tensile strain rates of 5×10 −4 , 5×10 −3 , and 5×10 −2 s −1 were selected in the tensile test. The deformation microstructures and fracture morphologies of the two steels after fracture in the tensile test were observed to analyze the tensile deformation response to different tensile strain rates. Results showed that the grain size of Mn12CrN steel was evidently refined after alloying with N+Cr. The grain would not become abnormally coarse even with increasing austenitizing temperature. During tensile deformation, the strength and plasticity of Mn12CrN steel were superior to those of Mn12 steel at the same strain rate. With increasing the strain rate, the changes in strength and plasticity of Mn12CrN steel were less sensitive to tensile strain rate compared with Mn12 steel. The effects of grain refinement and N+Cr alloying on dynamic strain aging and deformation twining behaviors were responsible for this lack of sensitivity to strain rate.

  14. A Modified Constitutive Model for Tensile Flow Behaviors of BR1500HS Ultra-High-Strength Steel at Medium and Low Temperature Regions

    Science.gov (United States)

    Zhao, Jun; Quan, Guo-Zheng; Pan, Jia; Wang, Xuan; Wu, Dong-Sen; Xia, Yu-Feng

    2018-01-01

    Constitutive model of materials is one of the most requisite mathematical model in the finite element analysis, which describes the relationships of flow behaviors with strain, strain rate and temperature. In order to construct such constitutive relationships of ultra-high-strength BR1500HS steel at medium and low temperature regions, the true stress-strain data over a wide temperature range of 293-873 K and strain rate range of 0.01-10 s-1 were collected from a series of isothermal uniaxial tensile tests. The experimental results show that stress-strain relationships are highly non-linear and susceptible to three parameters involving temperature, strain and strain rate. By considering the impacts of strain rate and temperature on strain hardening, a modified constitutive model based on Johnson-Cook model was proposed to characterize flow behaviors in medium and low temperature ranges. The predictability of the improved model was also evaluated by the relative error (W(%)), correlation coefficient (R) and average absolute relative error (AARE). The R-value and AARE-value for modified constitutive model at medium and low temperature regions are 0.9915 & 1.56 % and 0.9570 & 5.39 %, respectively, which indicates that the modified constitutive model can precisely estimate the flow behaviors for BR1500HS steel in the medium and low temperature regions.

  15. Tensile strength and durability characteristics of high-performance fiber reinforced concrete

    International Nuclear Information System (INIS)

    Ramadoss, P.; Nagamani, K.

    2008-01-01

    This paper presents investigations towards developing a better understanding of the contribution of steel fibers to the tensile strength of high-performance fiber reinforced concrete (HPFRC). For 32 series of mixes, flexural and splitting tensile strengths were determined at 28 days. The variables investigated were fiber volume fraction (0%, 0.5%, 1% and 1.5% with an aspect of 80), silica fume replacement level (SF/CM=0.05 and 0.10) and matrix composition (w/cm ratios ranging from 0.25 t 0.40). The influence of fiber content in terms of fiber reinforcing index on the flexural and splitting tensile strengths of HPFRC is presented. Comparative studies were performed on the tensile behavior of SFRC measured by two different loading tests: flexural test and splitting test. Based on the test results, using the least square method, empirical expressions were developed to predict 28-day tensile strength of HPFRC in terms of fiber reinforcing index. Durability tests were carried out to examine the performance of the SFRC. Relationship between flexural and splitting tensile strengths has been developed using regression analysis. The experimental values of previous researchers were compared with the values predicted by the empirical equations and the absolute variation obtained was within 6% and 5% for flexural and splitting tensile strengths respectively. (author)

  16. Nonlinear Fracture Mechanics and Plasticity of the Split Cylinder Test

    DEFF Research Database (Denmark)

    Olesen, John Forbes; Østergaard, Lennart; Stang, Henrik

    2006-01-01

    properties. This implies that the linear elastic interpretation of the ultimate splitting force in term of the uniaxial tensile strength of the material is only valid for special situations, e.g. for very large cylinders. Furthermore, the numerical analysis suggests that the split cylinder test is not well...... models are presented, a simple semi-analytical model based on analytical solutions for the crack propagation in a rectangular prismatic body, and a finite element model including plasticity in bulk material as well as crack propagation in interface elements. A numerical study applying these models...... demonstrates the influence of varying geometry or constitutive properties. For a split cylinder test in load control it is shown how the ultimate load is either plasticity dominated or fracture mechanics dominated. The transition between the two modes is related to changes in geometry or constitutive...

  17. Surface, structural and tensile properties of proton beam irradiated zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Rafique, Mohsin; Chae, San; Kim, Yong-Soo, E-mail: yongskim@hanyang.ac.kr

    2016-02-01

    This paper reports the surface, structural and tensile properties of proton beam irradiated pure zirconium (99.8%). The Zr samples were irradiated by 3.5 MeV protons using MC-50 cyclotron accelerator at different doses ranging from 1 × 10{sup 13} to 1 × 10{sup 16} protons/cm{sup 2}. Both un-irradiated and irradiated samples were characterized using Field Emission Scanning Electron Microscope (FESEM), X-ray Diffraction (XRD) and Universal Testing Machine (UTM). The average surface roughness of the specimens was determined by using Nanotech WSxM 5.0 develop 7.0 software. The FESEM results revealed the formation of bubbles, cracks and black spots on the samples’ surface at different doses whereas the XRD results indicated the presence of residual stresses in the irradiated specimens. Williamson–Hall analysis of the diffraction peaks was carried out to investigate changes in crystallite size and lattice strain in the irradiated specimens. The tensile properties such as the yield stress, ultimate tensile stress and percentage elongation exhibited a decreasing trend after irradiation in general, however, an inconsistent behavior was observed in their dependence on proton dose. The changes in tensile properties of Zr were associated with the production of radiation-induced defects including bubbles, cracks, precipitates and simultaneous recovery by the thermal energy generated with the increase of irradiation dose.

  18. Surface, structural and tensile properties of proton beam irradiated zirconium

    Science.gov (United States)

    Rafique, Mohsin; Chae, San; Kim, Yong-Soo

    2016-02-01

    This paper reports the surface, structural and tensile properties of proton beam irradiated pure zirconium (99.8%). The Zr samples were irradiated by 3.5 MeV protons using MC-50 cyclotron accelerator at different doses ranging from 1 × 1013 to 1 × 1016 protons/cm2. Both un-irradiated and irradiated samples were characterized using Field Emission Scanning Electron Microscope (FESEM), X-ray Diffraction (XRD) and Universal Testing Machine (UTM). The average surface roughness of the specimens was determined by using Nanotech WSxM 5.0 develop 7.0 software. The FESEM results revealed the formation of bubbles, cracks and black spots on the samples' surface at different doses whereas the XRD results indicated the presence of residual stresses in the irradiated specimens. Williamson-Hall analysis of the diffraction peaks was carried out to investigate changes in crystallite size and lattice strain in the irradiated specimens. The tensile properties such as the yield stress, ultimate tensile stress and percentage elongation exhibited a decreasing trend after irradiation in general, however, an inconsistent behavior was observed in their dependence on proton dose. The changes in tensile properties of Zr were associated with the production of radiation-induced defects including bubbles, cracks, precipitates and simultaneous recovery by the thermal energy generated with the increase of irradiation dose.

  19. Effects of liquid lead on 316l tensile properties

    International Nuclear Information System (INIS)

    Ionescu, V.; Pitigoi, V.; Nitu, A.; Hororoi, M.; Voicu, F.; Cojocaru, V.

    2016-01-01

    The lead-cooled fast reactor (LFR) is one of the concepts of the Generation IV reactor systems. Compatibility of the candidate structural materials with the liquid lead is known to be one of the critical issues to allow development of the LFR reactors. In contact with the liquid metal, the mechanical integrity of the structural materials can be affected. The steel.s mechanical properties are assessed by tensile testing as a function of temperature in heavy liquid metal and in an air environment. RATEN ICN is involved in several European projects aimed to Generation IV research activities. In a first stage an Experimental Facility for Tensile Tests in Liquid Lead environment has been set up. This installation is adapted on the Instron testing machine, already existing in institute. 316L alloy is one of a candidate structural material for this type of reactor. This document presents the effect of liquid lead on tensile properties of 316L material tested in liquid lead (in static conditions) and in air environment at 500°C, without oxygen monitoring system. When solid metals are placed in contact to liquid metals and stress is applied, they may undergo abrupt brittle failure. Stress-strain curves of slow strain rate tests have been obtained in conformity with ASTM, E-8. Mechanical characteristics determined are in accordance with literature. (authors)

  20. Monitoring tensile damage evolution in Nextel 312/BlackglasTM composites

    International Nuclear Information System (INIS)

    Kim, Jeongguk; Liaw, Peter K.

    2005-01-01

    Tensile damage evolution was monitored with the aid of nondestructive evaluation (NDE) techniques. Several NDE methods, such as ultrasonic testing (UT), infrared (IR) thermography, and acoustic emission (AE) techniques, were employed to analyze damage evolution during tensile testing of Nextel 312/Blackglas TM composites. Prior to tensile testing, UT was used to characterize the initial defect distribution of the samples. During tensile testing, AE sensors and an IR camera were used for in situ monitoring of the progressive damage of the samples. AE provided the amounts of damage evolution in terms of the AE intensity and/or energy, and the IR camera was used to obtain the temperature changes during the test. Microstructural characterization using scanning electron microscopy (SEM) was performed to investigate the fracture mechanisms and modes of Nextel 312/Blackglas TM samples. Moreover, SEM characterization was used to document failure behavior, and to show comparable results with NDE signatures

  1. Uniaxial Extensional Behavior of A--B--A Thermoplastic Elastomers: Structure-Properties Relationship and Modeling

    Science.gov (United States)

    Martinetti, Luca

    At service temperatures, A--B--A thermoplastic elastomers (TPEs) behave similarly to filled (and often entangled) B-rich rubbers since B block ends are anchored on rigid A domains. Therefore, their viscoelastic behavior is largely dictated by chain mobility of the B block rather than by microstructural order. Relating the small- and large-strain response of undiluted A--B--A triblocks to molecular parameters is a prerequisite for designing associated TPE-based systems that can meet the desired linear and nonlinear rheological criteria. This dissertation was aimed at connecting the chemical and topological structure of A--B--A TPEs with their viscoelastic properties, both in the linear and in the nonlinear regime. Since extensional deformations are relevant for the processing and often the end-use applications of thermoplastic elastomers, the behavior was investigated predominantly in uniaxial extension. The unperturbed size of polymer coils is one of the most fundamental properties in polymer physics, affecting both the thermodynamics of macromolecules and their viscoelastic properties. Literature results on poly(D,L-lactide) (PLA) unperturbed chain dimensions, plateau modulus, and critical molar mass for entanglement effect in viscosity were reviewed and discussed in the framework of the coil packing model. Self-consistency between experimental estimates of melt chain dimensions and viscoelastic properties was discussed, and the scaling behaviors predicted by the coil packing model were identified. Contrary to the widespread belief that amorphous polylactide must be intrinsically stiff, the coil packing model and accurate experimental measurements undoubtedly support the flexible nature of PLA. The apparent brittleness of PLA in mechanical testing was attributed to a potentially severe physical aging occurring at room temperature and to the limited extensibility of the PLA tube statistical segment. The linear viscoelastic response of A--B--A TPEs was first

  2. The influence of the tensile stress on magnetic breakdown in niobium

    International Nuclear Information System (INIS)

    Alekseevskii, N.E.; Glinski, M.; Nizhankovskii, V.I.

    1980-01-01

    It has been shown that magnetic breakdown takes place through the spin-orbital gaps between the hole octahedron of the second Brillouin zone and the open multiply connected surface of hole of the third zone, in two junctions. It is expected that even a small deformation of the sample, lowering the lattice symmetry should eliminate the magnetic breakdown by symmetry point contacts and should change the spectrum of the magnetic breakdown thermopower oscillations. Therefore, the influence of the uniaxial tensile stress on magnetic breakdown was investigated. Experimental details and results are given. The results indicate the change of the spin-orbit gap caused by stress is most probably anisotropic. (U.K.)

  3. Tensile properties of irradiated TZM and tungsten

    International Nuclear Information System (INIS)

    Steichen, J.M.

    1975-04-01

    The effect of neutron irradiation on the elevated temperature tensile properties of TZM and tungsten has been experimentally determined. Specimens were irradiated at a temperature of approximately 720 0 F to fluences of 0.4 and 0.9 x 10 22 n/cm 2 (E greater than 0.1 MeV). Test parameters for both control and irradiated specimens included strain rates from 3 x 10 -4 to 1 s -1 and temperatures from 72 to 1700 0 F. The results of these tests were correlated with a rate-temperature parameter (T ln A/epsilon) to provide a concise description of material behavior over the range of deformation conditions of this study. The yield strength of the subject materials was significantly increased by decreasing temperature, increasing strain rate, and increasing fluence. Ductility was significantly reduced at any temperature or strain rate by increasing fluence. Cleavage fractures occurred in both unirradiated and irradiated specimens when the yield strength was elevated to the effective cleavage stress by temperature and/or strain rate. Neutron irradiation for the conditions of this study increased the ductile-to-brittle transition temperature of tungsten by approximately 300 0 F and TZM by approximately 420 0 F. (U.S.)

  4. Material characterization of Inconel 718 from free bulging test at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Joon Tae; Yoon, Jong Hoon; Lee, Ho Sung [Korea Aerospace Research Institute, Daejeon (Korea, Republic of); Youn, Sung Kie [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2012-07-15

    Macroscopic superplastic behavior of metallic or non metallic materials is usually represented by the strain rate sensitivity, and it can be determined by tensile tests in uniaxial stress state and bulging tests in multi axial stress state, which is the actual hot forming process. And macroscopic behavior of Non SPF grade materials could be described in a similar way as that of superplastic materials, including strain hardening, cavity and so on. In this study, the material characterization of non SPF grade Inconel 718 has been carried out to determine the material parameters for flow stress throughout free bulging test under constant temperature. The measured height of bulged plate during the test was used for estimation of strain rate sensitivity, strain hardening index and cavity volume fraction with the help of numerical analysis. The bulged height obtained from the simulation showed good agreement with the experimental findings. The effects of strain hardening and cavity volume fraction factor for flow stress were also compared.

  5. Evolution of cleared channels in neutron-irradiated pure copper as a function of tensile strain

    DEFF Research Database (Denmark)

    Edwards, D.J.; Singh, B.N.

    2004-01-01

    Tensile specimens of pure copper were neutron irradiated at similar to323 K to a displacement dose of 0.3 dpa (displacement per atom). Five irradiated specimens were tensile tested at 300 K, but four of the specimens were stopped at specific strains -just before the yield point at similar to90......% of the macroscopic yield, at 1.5% and 5% elongation, and near the ultimate tensile strength at 14.5% elongation, with the 5th specimen tested to failure (e(T) = 22%). SEM and TEM characterization of the deformed specimens revealed that the plastic strain was confined primarily to the 'cleared' channels only...

  6. Infliximab treatment reduces tensile strength in intestinal anastomosis

    DEFF Research Database (Denmark)

    Jensen, Jonas Sanberg; Petersen, Nacie Bello; Biagini, Matteo

    2015-01-01

    :1) to receive either repeated IFX treatment or placebo. On day 15, three separate end-to-end anastomoses were performed on the jejunum. On postoperative day 5, tensile strength and bursting pressure for the anastomoses were tested and histologic changes examined. RESULTS: We found a significantly reduced...... as number of sutures in the tested anastomosis (coefficient = 0.51; P = 0.024). The general histologic score was significantly higher in the placebo group (5.00 +/- 1.26 versus 3.31 +/- 1.65, P = 0.03). CONCLUSIONS: Repeated high-dose IFX treatment reduces tensile strength significantly in rabbits...... effect on the healing process in intestinal anastomosis. The objective of this study was to examine the effect of repeated IFX treatment on anastomotic strength and degree of inflammation in the anastomotic line in the small intestine of rabbits. METHODS: Thirty-two rabbits were randomized (2...

  7. Behaviour of eggshell membranes at tensile loading

    Czech Academy of Sciences Publication Activity Database

    Strnková, M.J.; Nedomová, Š.; Trnka, Jan; Buchar, J.; Kumbár, V.

    46 B, December (2014), s. 44-48 ISSN 0324-1130 Institutional support: RVO:61388998 Keywords : eggshell membrane * tensile loading * loading rate * stress * strain strength Subject RIV: GM - Food Processing Impact factor: 0.201, year: 2014

  8. Use of miniature tensile specimen and video extensometer for measurement of mechanical properties

    International Nuclear Information System (INIS)

    Kumar, Kundan; Pooleery, Arun; Madhusoodanan, K.

    2014-08-01

    Miniaturisation of the tensile test specimen below the sub-size level poses various challenges, such as conformity of specimen to various acceptance criteria as per standard test specimen, aspect ratio, minimum number of grains required in a gauge cross-section, fabrication for uniformity in metrological values, etc. Apart from these, measurement of strain over a very limited available space on the test specimen is another practical challenge. Despite these limitations, miniature specimen testing is increasingly being used worldwide these days. The driving forces behind increasing use of miniature test techniques are new material development, assuring fitness of component after in-service-inspection, low dose of radiation exposure due to smaller dimensions of test specimens etc. However, the evaluation of mechanical properties from a miniature tensile test has a greater advantage over the other miniature novel test techniques, such as small punch test, ABI, miniature fatigue and impact tests etc., as it is a direct method of measurement of mechanical properties. This report covers various aspects of miniature tensile test methodologies, which include geometrical design of specimen having gauge length of 3-5 mm, fabrication, development of special fixtures for gripping the test specimens, and use of optical method for strain measurement. The geometrical design of the specimen and its behaviour over application of tensile load has been established using FEM analysis. A good agreement between conventional and miniature test results exemplifies the potential of the miniature tensile test technique. (author)

  9. Tensile properties of unirradiated path A PCA

    International Nuclear Information System (INIS)

    Braski, D.N.; Maziasz, P.J.

    1983-01-01

    The tensile properties of PCA in the Al (solution annealed), A3 (25%-cold worked), and B2 (aged, cold worked, and reaged) conditions were determined from room temperature to 600 0 C. The tensile behavior of PCA-A1 and -A3 was generally similar to that of titanium-modified type 316 stainless steel with similar microstructures. The PCA-B2 was weaker than PCA-A3, especially above 500 0 C, but demonstrated slightly better ducility

  10. Characteristics of Xanthosoma sagittifolium roots during cooking, using physicochemical analysis, uniaxial compression, multispectral imaging and low field NMR spectroscopy

    DEFF Research Database (Denmark)

    Boakye, Abena Achiaa; Gudjónsdóttir, María; Skytte, Jacob Lercke

    2017-01-01

    and white varieties of cocoyam roots were thus analysed by low field nuclear magnetic resonance relaxometry, multispectral imaging, uniaxial compression testing, and relevant physicochemical analysis in the current study. Both varieties had similar dry matter content, as well as physical and mechanical...... of that spectral region for rapid analysis of dry matter and water content of the roots. The small, but significant differences in the structural and gelatinization characteristics of the two varieties indicated that they may not be equally suited for further processing, e.g. to flours or starches. Processors thus...

  11. Effect of machining damage on tensile properties of beryllium

    International Nuclear Information System (INIS)

    Hanafee, J.E.

    1976-01-01

    It is well established that damage introduced at the surface of beryllium during machining operations can lower its mechanical properties. Tensile tests were conducted to illustrate this on beryllium presently being used for parts in the W79 program and similar to the new powder-processed beryllium specified for production (tentative specification MEL 76-001319). The objective of this study is to quantitatively illuminate the importance of controlling machining damage in this particular grade of powder-processed beryllium

  12. Evaluation of miniature tensile specimen fabrication techniques and performance

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, M.L. (Pacific Northwest Lab., Richland, WA (United States)); Blotter, M.A.; Edwards, D.J. (Missouri Univ., Rolla, MO (United States))

    1992-01-01

    The confident application of miniature tensile specimens requires adequate control over their fabrication and is facilitated by automated test and analysis techniques. Three fabrication processes -- punching, chemical, milling, and electrical discharge machining (EDM) -- were recently evaluated, leading to the replacement of the previously used punching technique with a wire EDM technique. The automated data acquisition system was upgraded, and an interactive data analysis program was developed.

  13. Evaluation of miniature tensile specimen fabrication techniques and performance

    International Nuclear Information System (INIS)

    Hamilton, M.L.; Blotter, M.A.; Edwards, D.J.

    1992-01-01

    The confident application of miniature tensile specimens requires adequate control over their fabrication and is facilitated by automated test and analysis techniques. Three fabrication processes -- punching, chemical, milling, and electrical discharge machining (EDM) -- were recently evaluated, leading to the replacement of the previously used punching technique with a wire EDM technique. The automated data acquisition system was upgraded, and an interactive data analysis program was developed

  14. Elastic-plastic analysis of the SS-3 tensile specimen

    International Nuclear Information System (INIS)

    Majumdar, S.

    1998-01-01

    Tensile tests of most irradiated specimens of vanadium alloys are conducted using the miniature SS-3 specimen which is not ASTM approved. Detailed elastic-plastic finite element analysis of the specimen was conducted to show that, as long as the ultimate to yield strength ratio is less than or equal to 1.25 (which is satisfied by many irradiated materials), the stress-plastic strain curve obtained by using such a specimen is representative of the true material behavior

  15. Study on Mechanical Features of Brazilian Splitting Fatigue Tests of Salt Rock

    Directory of Open Access Journals (Sweden)

    Weichao Wang

    2016-01-01

    Full Text Available The microtest, SEM, was carried out to study the fracture surface of salt rock after the Brazilian splitting test and splitting fatigue test were carried out with a servo-controlled test machine RMT-150B. The results indicate that the deviation of using the tablet splitting method is larger than that of using steel wire splitting method, in Brazilian splitting test of salt rock, when the conventional data processing method is adopted. There are similar deformation features in both the conventional splitting tests and uniaxial compression tests. The stress-strain curves include compaction, elasticity, yielding, and failure stage. Both the vertical deformation and horizontal deformation of splitting fatigue tests under constant average loading can be divided into three stages of “loosening-tightness-loosening.” The failure modes of splitting fatigue tests under the variational average loading are not controlled by the fracturing process curve of the conventional splitting tests. The deformation extent of fatigue tests under variational average loading is even greater than that of conventional splitting test. The tensile strength of salt rock has a relationship with crystallization conditions. Tensile strength of thick crystal salt rock is lower than the bonded strength of fine-grain crystals.

  16. Tensile properties of neutron irradiated 316Ti and 15-15Ti steels

    International Nuclear Information System (INIS)

    Fissolo, A.; Levy, V.; Seran, J.L.; Maillard, A.; Royer, J.; Rabouille, O.

    1992-01-01

    This paper deals with the tensile behavior of CW316Ti and CW15-15Ti Phenix fuel pin cladding. The tensile tests were conducted on defueled tubes irradiated up to 115 dpa 3 in the 400-640 deg C temperature range. Test temperature corresponds essentially to irradiation temperature. The results emphasize that although irradiation induces a reduction of ductility, failure always occurs with significant plastic deformation even for the most irradiated clads. (author). 15 refs., 12 figs., 1 tab

  17. Analysis of mechanical tensile properties of irradiated and annealed RPV weld overlay cladding

    Energy Technology Data Exchange (ETDEWEB)

    Novak, J [Czech Nuclear Society, Prague (Czech Republic)

    1994-12-31

    Mechanical tensile properties of irradiated and annealed outer layer of reactor pressure vessel weld overlay cladding, composed of Cr19Ni10Nb alloy, have been experimentally determined by conventional tensile testing and indentation testing. The constitutive properties of weld overlay cladding are then modelled with two homogenization models of the constitutive properties of elastic-plastic matrix-inclusion composites; numerical and experimental results are then compared. 10 refs., 4 figs., 4 tabs.

  18. Analysis of mechanical tensile properties of irradiated and annealed RPV weld overlay cladding

    International Nuclear Information System (INIS)

    Novak, J.

    1993-01-01

    Mechanical tensile properties of irradiated and annealed outer layer of reactor pressure vessel weld overlay cladding, composed of Cr19Ni10Nb alloy, have been experimentally determined by conventional tensile testing and indentation testing. The constitutive properties of weld overlay cladding are then modelled with two homogenization models of the constitutive properties of elastic-plastic matrix-inclusion composites; numerical and experimental results are then compared. 10 refs., 4 figs., 4 tabs

  19. Research on Al-alloy sheet forming formability during warm/hot sheet hydroforming based on elliptical warm bulging test

    Science.gov (United States)

    Cai, Gaoshen; Wu, Chuanyu; Gao, Zepu; Lang, Lihui; Alexandrov, Sergei

    2018-05-01

    An elliptical warm/hot sheet bulging test under different temperatures and pressure rates was carried out to predict Al-alloy sheet forming limit during warm/hot sheet hydroforming. Using relevant formulas of ultimate strain to calculate and dispose experimental data, forming limit curves (FLCS) in tension-tension state of strain (TTSS) area are obtained. Combining with the basic experimental data obtained by uniaxial tensile test under the equivalent condition with bulging test, complete forming limit diagrams (FLDS) of Al-alloy are established. Using a quadratic polynomial curve fitting method, material constants of fitting function are calculated and a prediction model equation for sheet metal forming limit is established, by which the corresponding forming limit curves in TTSS area can be obtained. The bulging test and fitting results indicated that the sheet metal FLCS obtained were very accurate. Also, the model equation can be used to instruct warm/hot sheet bulging test.

  20. Experimental study under uniaxial cyclic behavior at room and high temperature of 316L stainless steel

    International Nuclear Information System (INIS)

    Kang Guozheng; Gao Qing; Yang Xianjie; Sun Yafang

    2001-01-01

    An experimental study was carried out of the cyclic properties of 316L stainless steel subjected to uniaxial strain and stress at room and high temperature. The effects of cyclic strain amplitude, temperature and their histories on the cyclic deformation behavior of 316L stainless steel are investigated. And, the influences of stress amplitude, mean stress, temperature and their histories on ratcheting are also analyzed. It is shown that either uniaxial cyclic property under cyclic strain or ratcheting under asymmetric uniaxial cyclic stress depends not only on the current temperature and loading state, but also on the previous temperature and loading history. Some significant results are obtained