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Sample records for plastic bending analysis

  1. Simplified inelastic (plastic and creep) analysis of pipe elbows subjected to inplane and out-of-plane bending

    International Nuclear Information System (INIS)

    Mello, R.M.; Scheller, J.D.

    1975-01-01

    The inelastic analysis of elbows typical of use in Liquid Metal Fast Reactor piping systems is described. Detailed information on stresses, plastic and creep strains, and deformations throughout the elbow bodies resulting from elastic/plastic, elastic/plastic/creep, and elastic/plastic-creep/relaxation material behavior was obtained for the cases of applied inplane and out-of-plane moment loading on the elbows. Some conclusions are made concerning the nature of the resulting stresses in the elbows. The simplified pipe-bend element in the MARC nonlinear finite element program is used as the analytical tool. This element permits nonlinear analysis of piping elbows and pipeline systems at realistic cost. 16 refs

  2. Plastic fracture instability analysis of wall breakthrough in a circumferentially cracked pipe subjected to bending loads

    International Nuclear Information System (INIS)

    Zahoor, A.; Kanninen, M.F.

    1981-01-01

    A method of analyzing internal surface circumferential cracks in ductile reactor piping is presented. The method utilizes an alternate but equivalent definition of the J-integral based on nonlinear structural compliance. The analysis is valid for situations where the cross section containing the crack is fully yielded. Results are obtained for radial and circumferential crack growth for pipes subjected to bending. The stability of radial crack growth (wall breakthrough) is assessed using the J-integral-based tearing modulus approach. The analysis is shown to be in agreement with experimental results on the stability of surface crack growth in Type 304 stainless stee pipes. Example quantitative results for fracture instability assessments for nuclear piping are presented. 23 refs

  3. Plastic fracture instability analysis of wall breakthrough in a circumferentially cracked pipe subjected to bending loads

    Energy Technology Data Exchange (ETDEWEB)

    Zahoor, A.; Kanninen, M.F.

    1981-07-01

    A method of analyzing internal surface circumferential cracks in ductile reactor piping is presented. The method utilizes an alternate but equivalent definition of the J-integral based on nonlinear structural compliance. The analysis is valid for situations where the cross section containing the crack is fully yielded. Results are obtained for radial and circumferential crack growth for pipes subjected to bending. The stability of radial crack growth (wall breakthrough) is assessed using the J-integral-based tearing modulus approach. The analysis is shown to be in agreement with experimental results on the stability of surface crack growth in Type 304 stainless stee pipes. Example quantitative results for fracture instability assessments for nuclear piping are presented. 23 refs.

  4. Plastic loads of pipe bends under combined pressure and out-of-plane bending

    International Nuclear Information System (INIS)

    Lee, Kuk Hee; Kim, Yun Jae; Park, Chi Yong; Lee, Sung Ho; Kim, Tae Ryong

    2007-01-01

    Based on three-Dimensional (3-D) FE limit analyses, this paper provides plastic limit and TES(Twice- Elastic-Slope) loads for pipe bends under combined pressure and out-of-plane bending. The plastic limit loads are determined from FE limit analyses based on elastic.perfectly-plastic materials using the small geometry change option, and the FE limit analyses using the large geometry change option provide TES plastic loads. A wide range of parameters related to the bend geometry is considered. Based on the FE results, closed-form approximations of plastic limit and TES plastic load solutions for pipe bends under out-of-plane bending are proposed

  5. Plastic fracture mechanics prediction of fracture instability in a circumferentially cracked pipe in bending--1. J-integral analysis

    International Nuclear Information System (INIS)

    Zahoor, A.; Kanninen, M.F.

    1980-01-01

    A method of evaluating the J-integral for a circumferentially cracked pipe in bending is proposed. The method allows a J-resistance curve to be evaluated directly from the load-displacement record obtained in a pipe fracture experiment. This method also permits an analysis for fracture instability in a circumferential crack growth using a J-resistance curve and the tearing modulus parameter. The importance of using a J-resistance curve that is consistent with the type of constraint for a given application is emphasized. 18 refs

  6. Plastic fracture mechanics prediction of fracture instability in a circumferentially cracked pipe in bending - 1. J-integral analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zahoor, A.; Kanninen, M.F.

    1981-11-01

    A method of evaluating the J-integral for a circumferentially cracked pipe in bending is proposed. The method allows a J-resistance curve to be evaluated directly from the load-displacement record obtained in a pipe fracture experiment. It permits an analysis for fracture instability in a circumferential crack growth using a J-resistance curve and the tearing modulus parameter. The influence of the system compliance on fracture instability is discussed in conjunction with the latter application. The importance of using a J-resistance curve that is consistent with the type of constraint for a given application is emphasized. The possibility of a pipe fracture emanating from a stress corrosion crack in the heat-affected zones of girth-welds in Type 304 stainless steel pipes was investigated. The J-resistance curve was employed. A pipe fracture experiment was performed using a spring-loaded four-point bending system that simulated an 8.8-m long section of unsupported 102-mm-dia pipe. An initial through-wall crack of length equal to 104 mm was used. Fracture instability was predicted to occur between 15.2 and 22.1 mm of stable crack growth at each tip. In the actual experiment, the onset of fracture instability occurred beyond maximum load at an average stable crack growth of 11.7 to 19 mm at each tip. 24 refs.

  7. Plastic fracture mechanics prediction of fracture instability in a circumferentially cracked pipe in bending - 1. J-integral analysis

    International Nuclear Information System (INIS)

    Zahoor, A.; Kanninen, M.F.

    1981-01-01

    A method of evaluating the J-integral for a circumferentially cracked pipe in bending is proposed. The method allows a J-resistance curve to be evaluated directly from the load-displacement record obtained in a pipe fracture experiment. It permits an analysis for fracture instability in a circumferential crack growth using a J-resistance curve and the tearing modulus parameter. The influence of the system compliance on fracture instability is discussed in conjunction with the latter application. The importance of using a J-resistance curve that is consistent with the type of constraint for a given application is emphasized. The possibility of a pipe fracture emanating from a stress corrosion crack in the heat-affected zones of girth-welds in Type 304 stainless steel pipes was investigated. The J-resistance curve was employed. A pipe fracture experiment was performed using a spring-loaded four-point bending system that simulated an 8.8-m long section of unsupported 102-mm-dia pipe. An initial through-wall crack of length equal to 104 mm was used. Fracture instability was predicted to occur between 15.2 and 22.1 mm of stable crack growth at each tip. In the actual experiment, the onset of fracture instability occurred beyond maximum load at an average stable crack growth of 11.7 to 19 mm at each tip. 24 refs

  8. Determination of post-shakedown quantities of a pipe bend via the simplified theory of plastic zones compared with load history dependent incremental analysis

    Science.gov (United States)

    Vollrath, Bastian; Hübel, Hartwig

    2018-01-01

    The Simplified Theory of Plastic Zones (STPZ) may be used to determine post-shakedown quantities such as strain ranges and accumulated strains at plastic or elastic shakedown. The principles of the method are summarized. Its practical applicability is shown by the example of a pipe bend subjected to constant internal pressure along with cyclic in-plane bending or/and cyclic radial temperature gradient. The results are compared with incremental analyses performed step-by-step throughout the entire load history until the state of plastic shakedown is achieved.

  9. Conversion of fracture toughness testing values from small scale three point bending test specimens to small scale yielding state (SSY) by elastic-plastic stress analysis

    International Nuclear Information System (INIS)

    Ikonen, K.

    1993-07-01

    The report describes the work performed for achieving readiness to calculate fracture toughness dependence on dimension effects and loading conditions in fracture test specimens and real structures. In the report two- and three-dimensional computer codes developed and calculational methods applied are described. One of the main goals is to converse fracture toughness from small scale three point bending test specimens to case of a depth crack in plane strain i.e. to small scale yielding state (SSY) by numerical elastic-plastic stress analysis. Thickness effect of a test specimens and effect of a crack depth are separately investigated. Tests of three point bending specimens with and without sidegrooves and curved crack front are numerically simulated and experimental and computed results are compared. J-integral is calculated along crack front and also from force-deflection dependence of the beam. For the analyses the computing system was thoroughly automatized. Measuring capacity of three point bending test specimens was tried to evaluate. (orig.) (7 refs., 54 figs.)

  10. A comparison of plastic collapse and limit loads for single mitred pipe bends under in-plane bending

    International Nuclear Information System (INIS)

    Neilson, R.; Wood, J.; Hamilton, R.; Li, H.

    2010-01-01

    This paper presents a comparison of the plastic collapse loads from experimental in-plane bending tests on three 90 o single un-reinforced mitred pipe bends, with the results from various 3D solid finite element models. The bending load applied reduced the bend angle and in turn, the resulting cross-sectional ovalisation led to a recognised weakening mechanism. In addition, at maximum load there was a reversal in stiffness, characteristic of buckling. This reversal in stiffness was accompanied by significant ovalisation and plasticity at the mitre intersection. Both the weakening mechanism and the post-buckling behaviour are only observable by testing or by including large displacement effects in the plastic finite element solution. A small displacement limit solution with an elastic-perfectly plastic material model overestimated the collapse load by more than 40% and could not reproduce the buckling behaviour. The plastic collapse finite element solution, with large displacements, produced excellent agreement with the experiment. Sufficient experimental detail is presented for these results to be used as a benchmark for analysts in this area. Given the robustness of non-linear solutions in commercial finite element codes and the ready availability of computing resources, it is argued that pressure vessel code developers should now be recommending large displacement analysis as the default position for limit and plastic collapse analyses, rather than expecting engineers to anticipate weakening mechanisms and related non-linear phenomena.

  11. Estimates of plastic loads for pipe bends under combined in-plane and out-of-plane bending moment

    International Nuclear Information System (INIS)

    Kim, Nak Hyun; Oh, Chang Sik; Kim, Yun Jae

    2008-01-01

    This paper provides a method to estimate plastic loads (defined by twice-elastic-slope) for pipe bends under combined in-plane and out-of-plane bending moment, based on detailed 3-D FE limit analyses using elastic-perfectly plastic materials. Because closing bending moment is always lower than opening bending moment, the combination of in-plane closing bending and out-of-plane bending moment becomes the most significant case. Due to conservatism of each bending moments, the resultant moment provided by ASME B and PV code is unduly conservative. However, the concept of the resultant moment is still valid. In this paper, FE results show that the accurate solutions of bending moments provide better estimates of plastic loads of pipe bend under combined in-plane bending and out-of-plane bending moment

  12. Closed-form plastic collapse loads of pipe bends under combined pressure and in-plane bending

    International Nuclear Information System (INIS)

    Oh, Chang Sik; Kim, Yun Jae

    2006-01-01

    Based on three-dimensional (3-D) FE limit analyses, this paper provides plastic limit, collapse and instability load solutions for pipe bends under combined pressure and in-plane bending. The plastic limit loads are determined from FE limit analyses based on elastic-perfectly plastic materials using the small geometry change option, and the FE limit analyses using the large geometry change option provide plastic collapse loads (using the twice-elastic-slope method) and instability loads. For the bending mode, both closing bending and opening bending are considered, and a wide range of parameters related to the bend geometry is considered. Based on the FE results, closed-form approximations of plastic limit and collapse load solutions for pipe bends under combined pressure and bending are proposed

  13. On the bending of structural materials with plastic anisotropic effect

    Science.gov (United States)

    Lachugin, D. V.; Pavilaynen, G. V.

    2018-05-01

    The study of a deformation features of metal alloys which are sensitive to tension or compression loading is an important technical challenge in the design and creation of a new shipbuilding and aircraft constructions. We use a mathematical model for the elastic-plastic bending of such material where SD(strength-different) parameter is taken into account. The problem is solved analytically and numerically. As an example of the material with the SD-effect the steel alloy is considered.

  14. Dynamic elastic-plastic behaviour of a frame including coupled bending and torsion

    International Nuclear Information System (INIS)

    Messmer, S.; Sayir, M.

    1989-01-01

    The full time response of a space frame under impact loading perpendicular to the frame plane is discussed. Theoretical solutions and experimental results are presented and compared. A space frame clamped at its two ends is loaded by a 0.22 lead bullet that hits a mass in the middle of the transversal beam of the frame. The loading time is about 40 to 60 μs and the resulting linear momentum of the impact in the experiment is 0.5 to 1 N s. The time response of this frame can be divided in four phases where different physical effects are dominant: (a) The loading phase where elastic wave motion dominates the time response. Because of the high impact forces, plastic deformation occurs in the vicinity of the mass and must be included in a theoretical model. The influence of reflections at the corners on the time response is shown in theory and experiment. (b) The evolution phase. Within this phase, a plastic collapse mechanism develops. Most of this phase is dominated by elastic deformation but local plastic deformations beside the mass are also present. Because many reflections at corners, clamps and the mass occur within this phase, a modal analysis method is used to predict time histories. (c) The plastic phase with plastic zones at the clamps. The phase sets in after the bending wave reaches the clamps. It is characterized by plastic deformation near the clamps and elastic deformation of the other parts of the frame. We used a modal analysis including plastic 'modes' to get accurate results. (d) The elastic vibration phase

  15. Elasto-plastic behavior of pipe subjected to steady axial load and cyclic bending

    International Nuclear Information System (INIS)

    Yao Yanping; Lu Mingwan; Zhang Xiong

    2004-01-01

    The elasto-plastic behavior of a pipe subjected to a steady axial force and a cyclic bending moment is studied. By using two parameters c and d, which describe the elasto-plastic interfaces of beam cross-section, the boundary curve equations between various types of elasto-plastic behavior, such as shakedown, plastic fatigue, ratcheting, and plastic collapse, are derived. The results are applicable for beams of any cross-section with two orthogonal axes of symmetry. As a result, the load regime diagram for a pipe is obtained, which gives an intuitive picture of the elasto-plastic behavior of the pipe under a given combination of constant axial load and cyclic bending moment

  16. Modelling Elasto-Plastic Behaviour of Human Single Trabecula-Comparison with Bending Test

    Czech Academy of Sciences Publication Activity Database

    Zlamal, P.; Jiroušek, Ondřej; Doktor, Tomáš; Kytýř, Daniel

    2012-01-01

    Roč. 45, S1 (2012), s. 479-479 ISSN 0021-9290 R&D Projects: GA ČR(CZ) GAP105/10/2305 Institutional support: RVO:68378297 Keywords : digital image correlation * elasto-plastic material model * FEM * three-point bending * trabecular bone Subject RIV: FI - Traumatology, Orthopedics Impact factor: 2.716, year: 2012

  17. Thermal Analysis of Bending Under Tension Test

    DEFF Research Database (Denmark)

    Ceron, Ermanno; Martins, Paulo A.F.; Bay, Niels

    2014-01-01

    during testing is similar to the one in the production tool. A universal sheet tribo-tester has been developed, which can run multiple tests automatically from coil. This allows emulating the temperature increase as in production. The present work performs finite element analysis of the evolution......The tribological conditions in deep drawing can be simulated in the Bending Under Tension test to evaluate the performance of new lubricants, tool materials, etc. Deep drawing production with automatic handling runs normally at high rate. This implies considerable heating of the tools, which...... sometimes can cause lubricant film breakdown and galling. In order to replicate the production conditions in bending under tension testing it is thus important to control the tool/workpiece interface temperature. This can be done by pre-heating the tool, but it is essential that the interface temperature...

  18. A new approach for elasto-plastic finite strain analysis of cantilever ...

    Indian Academy of Sciences (India)

    A new approach for elasto-plastic finite strain analysis of cantilever beams subjected to uniform bending moment ... Curvature; deflection curve; cantilever beam; elasto-plastic analysis; tapered beam subjected to tipmoment; ... Sadhana | News.

  19. Plastic deformation behavior and bonding strength of an EBW joint between 9Cr-ODS and JLF-1 estimated by symmetric four-point bend tests combined with FEM analysis

    International Nuclear Information System (INIS)

    Fu, Haiying; Nagasaka, Takuya; Muroga, Takeo; Guan, Wenhai; Nogami, Shuhei; Serizawa, Hisashi; Geng, Shaofei; Yabuuchi, Kiyohiro; Kimura, Akihiko

    2016-01-01

    The joint between 9Cr-ODS and JLF-1 made by electron beam welding (EBW) fractured at the JLF-1 base metal (BM) during uniaxial tensile tests. Thus, the bonding strength of the joint was not determined and was estimated as more than the ultimate tensile strength of the BM in this case. Symmetric four-point bend tests which concentrate the stress inside the inner span including the weld metal (WM) were carried out at room temperature (RT) and 550 °C to investigate how the bonding strength is more than the ultimate tensile strength of the BM. The normal stress at the center of the weld bead can be calculated with elastic theory up to only 0.25% in strain, though the joint showed more than 10% in strain due to plastic deformation. Thus, finite element method (FEM) was utilized to simulate the plastic deformation behavior of the joint during bend tests. According to the fitting of the FEM output, such as load and displacement of the upper jig contacting the specimens, to the experimental results, the bonding strength of the joint at RT and 550 °C were estimated as 854 MPa and 505 MPa, respectively.

  20. Plastic deformation behavior and bonding strength of an EBW joint between 9Cr-ODS and JLF-1 estimated by symmetric four-point bend tests combined with FEM analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Haiying [SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi-cho, Toki 509-5292 (Japan); Nagasaka, Takuya; Muroga, Takeo [SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi-cho, Toki 509-5292 (Japan); National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Guan, Wenhai; Nogami, Shuhei [Tohoku University, 6-6-01-2 Aramaki-aza-Aoba, Aoba-ku, Sendai 980-8578 (Japan); Serizawa, Hisashi [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki 567-0047 (Japan); Geng, Shaofei [SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi-cho, Toki 509-5292 (Japan); Yabuuchi, Kiyohiro; Kimura, Akihiko [Institute of Advanced Energy, Kyoto University, Uji 611-0011 (Japan)

    2016-01-15

    The joint between 9Cr-ODS and JLF-1 made by electron beam welding (EBW) fractured at the JLF-1 base metal (BM) during uniaxial tensile tests. Thus, the bonding strength of the joint was not determined and was estimated as more than the ultimate tensile strength of the BM in this case. Symmetric four-point bend tests which concentrate the stress inside the inner span including the weld metal (WM) were carried out at room temperature (RT) and 550 °C to investigate how the bonding strength is more than the ultimate tensile strength of the BM. The normal stress at the center of the weld bead can be calculated with elastic theory up to only 0.25% in strain, though the joint showed more than 10% in strain due to plastic deformation. Thus, finite element method (FEM) was utilized to simulate the plastic deformation behavior of the joint during bend tests. According to the fitting of the FEM output, such as load and displacement of the upper jig contacting the specimens, to the experimental results, the bonding strength of the joint at RT and 550 °C were estimated as 854 MPa and 505 MPa, respectively.

  1. Measurements of the Minimum Bending Radius of Small Diameter Scintillating Plastic Fibres

    CERN Document Server

    Gruber, Lukas; Vaananen, Mika Petteri; Gavardi, Laura

    2018-01-01

    The minimum bending radius of plastic fibres is an important parameter as it determines the geometrical flexibility of the fibres during long-term storage or installation and usage inside detectors. The following document describes measurements of the minimum bending radius of round scintillating plastic fibres with small diameter performed in the context of the LHCb SciFi Tracker project. The experimental set-up is based on measuring the light output of a bent fibre in response to 1 MeV electrons over several days. The results suggest that the 250 μm diameter fibres can be bent to a radius of about 10 mm without damaging and losing light.

  2. Limit loads for pipe bends under combined pressure and in-plane bending based on finite element limit analysis

    International Nuclear Information System (INIS)

    Oh, Chang Sik; Kim, Yun Jae

    2006-01-01

    In the present paper, approximate plastic limit load solutions for pipe bends under combined internal pressure and bending are obtained from detailed three-dimensional (3-D) FE limit analyses based on elastic-perfectly plastic materials with the small geometry change option. The present FE results show that existing limit load solutions for pipe bends are lower bounds but can be very different from the present FE results in some cases, particularly for bending. Accordingly closed-form approximations are proposed for pipe bends under combined pressure and in-plane bending based on the present FE results. The proposed limit load solutions would be a basis of defective pipe bends and be useful to estimate non-linear fracture mechanics parameters based on the reference stress approach

  3. Evaluation Model for Restraint Effect of Pressure Induced Bending on the Plastic Crack Opening of Circumferential Through-Wall-Crack

    International Nuclear Information System (INIS)

    Kim, Jin-Weon

    2006-01-01

    Most of the pipe crack evaluation procedures, including leak-before-break (LBB) analysis, assume that the cracked pipe subjected to remote bending or internal pressure is free to rotate. In this case, the pressure induced bending (PIB) enhances crack opening of a through-wall-crack (TWC) in a pipe. In a real piping system, however, the PIB will be restrained because the ends of the pipe are constrained by the rest of the piping system. Hence, the amount of restraint affects the crack opening of a TWC in a pipe, and the restraint effect on crack opening directly affects the results of LBB evaluation. Therefore, it is necessary to investigate the restraint effect of PIB on crack opening displacement (COD) to quantify the uncertainties in current analysis procedures and to ensure the application of LBB concepts to nuclear piping systems. Recently, several researches were conducted to investigate the restraint effect of PIB on COD, and they proposed a simplified model to evaluate COD under restrained conditions. However, these results are quite limited because the restraint effect was evaluated only in terms of linear-elastic crack opening. In practice, the TWC in a pipe behaves plastically under normal operating loads, and the current LBB analysis methodologies require elastic-plastic crack opening evaluation. Therefore, this study evaluates the restraint effect of PIB on the plastic crack opening of a TWC in a pipe using finite element analysis under various influencing parameters. Based on these results, a closed-from model to be able to estimate the restraint effect of PIB on plastic crack opening is proposed

  4. Global plastic models for computerized structural analysis

    International Nuclear Information System (INIS)

    Roche, R.L.; Hoffmann, A.

    1977-01-01

    In many types of structures, it is possible to use generalized stresses (like membrane forces, bending moment, torsion moment...) to define a yield surface for a part of the structure. Analysis can be achieved by using the HILL's principle and a hardening rule. The whole formulation is said 'Global Plastic Model'. Two different global models are used in the CEASEMT system for structural analysis, one for shell analysis and the other for piping analysis (in plastic or creep field). In shell analysis the generalized stresses chosen are the membrane forces and bending (including torsion) moments. There is only one yield condition for a normal to the middle surface and no integration along the thickness is required. In piping analysis, the choice of generalized stresses is bending moments, torsional moment, hoop stress and tension stress. There is only a set of stresses for a cross section and no integration over the cross section area is needed. Connected strains are axis curvature, torsion, uniform strains. The definition of the yield surface is the most important item. A practical way is to use a diagonal quadratic function of the stress components. But the coefficients are depending of the shape of the pipe element, especially for curved segments. Indications will be given on the yield functions used. Some examples of applications in structural analysis are added to the text

  5. Finite Element Analysis for Bending Process of U-Bending Specimens

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Dong; Bahn, Chi Bum [Pusan National University, Busan (Korea, Republic of)

    2015-10-15

    ASTM G30 suggests that the applied strain can be calculated by dividing thickness by a bend radius. It should be noted, however, that the formula is reliable under an assumption that the ratio of thickness to bend radius is less than 0.2. Typically, to increase the applied stress/strain, the ratio of thickness to bend radius becomes larger than 0.2. This suggests that the estimated strain values by ASTM G30 are not reliable to predict the actual residual strain state of the highly deformed U-bend specimen. For this reason, finite element analysis (FEA) for the bending process of Ubend specimens was conducted by using a commercial finite element analysis software ABAQUS. ver.6.14- 2;2014. From the results of FEA, PWSCC initiation time and U-bend specimen size can be determined exactly. Since local stress and strain have a significant effect on the initiation of PWSCC, it was inappropriate to apply results of ASTM G30 to the PWSCC test directly. According to results of finite element analysis (FEA), elastic relaxation can cause inaccuracy in intended final residual stress. To modify this inaccuracy, additional process reducing the spring back is required. However this additional process also may cause uncertainty of stress/strain state. Therefore, the U-bending specimen size which is not creating uncertainty should be optimized and selected. With the bending radius of 8.3 mm, the thickness of 3 mm and the roller distance of 32.6 mm, calculated maximum stress and strain were 670 MPa and 0.21, respectively.

  6. RELIABILITY ANALYSIS OF BENDING ELIABILITY ANALYSIS OF ...

    African Journals Online (AJOL)

    eobe

    Reliability analysis of the safety levels of the criteria slabs, have been .... was also noted [2] that if the risk level or β < 3.1), the ... reliability analysis. A study [6] has shown that all geometric variables, ..... Germany, 1988. 12. Hasofer, A. M and ...

  7. Structural analysis of suerconducting bending magnets

    International Nuclear Information System (INIS)

    Meuser, R.B.

    1980-05-01

    Mechanical stresses, displacements, and the effects of displacements upon aberrations of the magnetic field in the aperture have been calculated for a class of superconducting bending-magnet configurations. The analytical model employed for the coil is one in which elements are free to slide without restraint upon each other, and upon the surrounding structure. Coil configurations considered range from an idealized one in which the current density varies as cosine theta to more realistic ones consisting of regions of uniform current density. With few exceptions, the results for the more realistic coils closely match those of the cos theta coil

  8. Design Analysis of the Mixed Mode Bending Sandwich Specimen

    DEFF Research Database (Denmark)

    Quispitupa, Amilcar; Berggreen, Christian; Carlsson, Leif A.

    2010-01-01

    A design analysis of the mixed mode bending (MMB) sandwich specimen for face–core interface fracture characterization is presented. An analysis of the competing failure modes in the foam cored sandwich specimens is performed in order to achieve face–core debond fracture prior to other failure modes...... for the chosen geometries and mixed mode loading conditions....

  9. Global plastic models for computerized structural analysis

    International Nuclear Information System (INIS)

    Roche, R.; Hoffmann, A.

    1977-01-01

    Two different global models are used in the CEASEMT system for structural analysis, one for the shells analysis and the other for piping analysis (in plastic or creep field). In shell analysis the generalized stresses choosed are the membrane forces Nsub(ij) and bending (including torsion) moments Msub(ij). There is only one yield condition for a normal (to the middle surface) and no integration along the thickness is required. In piping analysis, the choice of generalized stresses is: bending moments, torsional moments, Hoop stress and tension stress. There is only a set of stresses for a cross section and non integration over the cross section area is needed. Connected strains are axis curvature, torsion, uniform strains. The definition of the yield surface is the most important item. A practical way is to use a diagonal quadratic fonction of the stress components. But the coefficients are depending of the shape of the pipe element, especially for curved segments. Indications will be given on the yield fonctions used. Some examples of applications in structural analysis are added to the text [fr

  10. Elastic-plastic fracture analysis of carbon steel piping using the latest CEGB R6 approach

    International Nuclear Information System (INIS)

    Kanno, S.; Hasegawa, K.; Shimizu, T.; Kobayashi, H.

    1991-01-01

    The elastic-plastic fracture of carbon steel piping having various pipe diameters and circumferential crack angles and subjected to a bending moment is analyzed using the latest United Kingdom Central Electricity Generating Board R6 approach. The elastic-plastic fracture criterion must be applied instead of the plastic collapse criterion with increase of the pipe diameter and the crack angle. A simplified elastic-plastic fracture analysis procedure based on the R6 approach is proposed. (author)

  11. Photoelastic stress analysis in mitred bend under internal pressure

    International Nuclear Information System (INIS)

    Sawa, Yoshiaki

    1987-01-01

    The stress analysis and stress relaxation in mitred bend subjected to internal pressure have been studied by means of the photoelastic stress freezing method. The experimental results show that stress concentration occurs in the wedge tip of the intersectional plane and it is considerably influenced by the bent angle. Then, the stress relaxation was obtained by planing the wedge tip. (author)

  12. Analysis of Bending Waves in Phononic Crystal Beams with Defects

    Directory of Open Access Journals (Sweden)

    Yongqiang Guo

    2018-01-01

    Full Text Available Existing investigations on imperfect phononic crystal beams mainly concern periodic multi-span beams carrying either one or two channel waves with random or deterministic disorder in span-length. This paper studies the two channel bending waves in phononic crystal beams consisting of many phases of materials with defects introduced as one structural segment having different cross-sectional dimensions or material parameters. The method of reverberation-ray matrix (MRRM based on the Timoshenko beam theory, which can conduct high-frequency analysis, is extended for the theoretical analysis of dispersion and transmission of bending waves. The supercell technique and the Floquet–Bloch theorem are adopted for modeling the dispersion characteristics, and the whole finite structural model is used to calculate the transmission spectra. Experimental measurements and numerical calculations are provided to validate the displacement transmission obtained by the proposed MRRM, with the effect of damping on transmission spectra being concerned. The high-frequency calculation applicability of the proposed MRRM is also confirmed by comparing the present results with the corresponding ones either using the transfer matrix method (TMM or MRRM based on Euler—Bernoulli beam theory. The influences of defect size, defect form, and unit-cell number on the transmission spectra and the band structures are discussed. The drawn conclusions may be useful for designing or evaluating the defected phononic crystal beams in bending wave control. In addition, our conclusions are especially potential for identifying the defect location through bending wave signals.

  13. Crack initiation life analysis in notched pipe under cyclic bending loads

    International Nuclear Information System (INIS)

    Lee, Joon Seong; Kwak, Sang Log; Kim, Young Jin; Park, Youn Won

    2001-01-01

    In order to improve leak-before-break methodology, more precisely the crack growth evaluation, a round robin analysis was proposed by the CEA Saclay. The aim of this analysis was to evaluate the crack initiation life, penetration life and shape of through wall crack under cyclic bending loads. The proposed round robin analysis is composed of three main topic; fatigue crack initiation, crack propagation and crack penetration. This paper deals with the first topic, crack initiation in a notched pipe under four point bending. Both elastic-plastic finite element analysis and Neuber's rule were used to estimate the crack initiation life and the finite element models were verified by mesh-refinement, stress distribution and global deflection. In elastic-plastic finite element analysis, crack initiation life was determined by strain amplitude at the notch tip and strain-life curve of the material. In the analytical method, Neuber's rule with the consideration of load history and mean stress effect, was used for the life estimation. The effect of notch tip radius, strain range, cyclic hardening rule were examined in this study. When these results were compared with the experimental ones, the global deformation was a good agreement but crack initiation cycle was higher than the experimental result

  14. Crack initiation life analysis in notched pipe under cyclic bending loads

    International Nuclear Information System (INIS)

    Goak, S. R.; Kim, Y. J.; Lee, J. S.; Park, Y. W.

    2000-01-01

    In order to improve LBB(Leak-Before-Break) methodology, more precisely the crack growth evaluation, a benchmark problem was proposed by the CEA Saclay. The aim of this benchmark analysis was to evaluate the crack growth in a notched pipe under cyclic bending loads. The proposed benchmark analysis is composed of three main topic; fatigue crack initiation, crack propagation and crack penetration. This paper deals with the first topic, crack initiation in a notched pipe under four point bending. Both elastic-plastic finite element analysis and Neuber's rule were used to estimate the crack initiation life and the finite element models were verified by mesh-refinement, stress distribution and global deflection. In elastic-plastic finite element analysis, crack initiation life was determined by strain amplitude at the notch tip and strain-life curve of the material. In the analytical method, Neuber's rule with the consideration of load history and mean stress effect, was used for the life estimation. The effect of notch tip radius, strain range, cyclic hardening rule were examined in this study. When these results were compared with the experimental ones, the global deformation was a good agreement but the crack initiation cycle was higher than the experimental result

  15. Leak-before-break analysis of thermally aged nuclear pipe under different bending moments

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Xuming; Li, Shilei; Zhang, Hailong; Wang, Yanli; Wang, Xitao [University of Science and Technology Beijing, Beijing (China); Wang, Zhaoxi [CPI Nuclear Power Institute, Beijing (China); Xue, Fei [Suzhou Nuclear Power Research Institute, Suzhou (China)

    2015-10-15

    Cast duplex stainless steels are susceptible to thermal aging during long-term service at temperatures ranging from 280°C to 450°C. To analyze the effect of thermal aging on leak-before-break (LBB) behavior, three-dimensional finite element analysis models were built for circumferentially cracked pipes. Based on the elastic–plastic fracture mechanics theory, the detectable leakage crack length calculation and J-integral stability assessment diagram approach were carried out under different bending moments. The LBB curves and LBB assessment diagrams for unaged and thermally aged pipes were constructed. The results show that the detectable leakage crack length for thermally aged pipes increases with increasing bending moments, whereas the critical crack length decreases. The ligament instability line and critical crack length line for thermally aged pipes move downward and to the left, respectively, and unsafe LBB assessment results will be produced if thermal aging is not considered. If the applied bending moment is increased, the degree of safety decreases in the LBB assessment.

  16. Static-transmission-error vibratory-excitation contributions from plastically deformed gear teeth caused by tooth bending-fatigue damage

    Science.gov (United States)

    Mark, W. D.; Reagor, C. P.

    2007-02-01

    To assess gear health and detect gear-tooth damage, the vibratory response from meshing gear-pair excitations is commonly monitored by accelerometers. In an earlier paper, strong evidence was presented suggesting that, in the case of tooth bending-fatigue damage, the principal source of detectable damage is whole-tooth plastic deformation; i.e. yielding, rather than changes in tooth stiffness caused by tooth-root cracks. Such plastic deformations are geometric deviation contributions to the "static-transmission-error" (STE) vibratory excitation caused by meshing gear pairs. The STE contributions caused by two likely occurring forms of such plastic deformations on a single tooth are derived, and displayed in the time domain as a function of involute "roll distance." Example calculations are provided for transverse contact ratios of Qt=1.4 and 1.8, for spur gears and for helical-gear axial contact ratios ranging from Qa=1.2 to Qa=3.6. Low-pass- and band-pass-filtered versions of these same STE contributions also are computed and displayed in the time domain. Several calculations, consisting of superposition of the computed STE tooth-meshing fundamental harmonic contribution and the band-pass STE contribution caused by a plastically deformed tooth, exhibit the amplitude and frequency or phase modulation character commonly observed in accelerometer-response waveforms caused by damaged teeth. General formulas are provided that enable computation of these STE vibratory-excitation contributions for any form of plastic deformation on any number of teeth for spur and helical gears with any contact ratios.

  17. PLASTIC ANALYSIS OF STEEL FRAME STRUCTURE

    Directory of Open Access Journals (Sweden)

    M. Rogac

    2013-05-01

    Full Text Available This paper presents the plastic analysis of steel frame structure loaded by gravity loads. By applying the cinematic theorem of ultimate analysis, the ultimate load for the case of elastic - ideally plastic material is calculated. The identical structure was treated in the computer program SAP2000 where the zone of material reinforcement in the plastic area was covered. Keywords: Steel frame structure, plastic analysis, ultimate gravity load, material reinforcement.

  18. Plastic plate bending problem with friction on the boundary and uncertain input data

    Czech Academy of Sciences Publication Activity Database

    Hlaváček, Ivan

    2010-01-01

    Roč. 31, č. 4 (2010), s. 414-439 ISSN 0163-0563 R&D Projects: GA AV ČR(CZ) IAA100190803 Institutional research plan: CEZ:AV0Z10190503 Keywords : anti- optimization * deformation theory of plasticity * Kačanov method * uncertain input data * worst scenario Subject RIV: BA - General Mathematics Impact factor: 0.687, year: 2010 http://www.tandfonline.com/doi/abs/10.1080/01630563.2010.483311

  19. Development of plastic deformations in 12Kh18N10T steel under cyclic symmetrical bending of specimens of various length

    Energy Technology Data Exchange (ETDEWEB)

    Pisarenko, G.S.; Leonets, V.A.; Bega, N.D. (AN Ukrainskoj SSR, Kiev. Inst. Problem Prochnosti)

    1983-08-01

    Effect of specimen length on intensity of plastic deformation development and cyclic strength is studied for annealed 12Kh18N10T steel under cyclic symmetrical bending. The intensity of microplastic deformations and cyclic strength of annealed 12Kh18N10T steel in the considered case is due to self-heating.

  20. An analysis of a pipe bend subjected to in-plane loads

    International Nuclear Information System (INIS)

    Hellen, T.K.

    1979-01-01

    This report describes a set of finite element analyses conducted on a pipe bend subjected to in-plane loads. The pipe is thin-walled, and two types of finite element, shells and solid bricks, are compared elastically. An alternative semi-analytical technique has also been used and experimental results are available, all of which show good correlative agreement. The use of suitable mesh refinement and order of numerical integration is examined. Finally, the solid elements are used to follow a loading sequence incorporating elasto-plastic behaviour as conducted by experiment. This work is an updated version of that used for the CEC benchmark calculations for the Fast Reactor Codes and Standards Working Group, Activity No 2, on Structural Analysis. (author)

  1. kantorovich-euler lagrange-galerkin's method for bending analysis

    African Journals Online (AJOL)

    user

    OF CIVIL ENGINEERING, ENUGU STATE UNIVERSITY OF SCIENCE & TECHNOLOGY, ... In this work, the Kantorovich method is applied to solve the bending problem of thin ... Lagrange differential equation is determined for this functional.

  2. Numerical analysis and optimization of 3D magnetohydrodynamic flows in rectangular U-bend

    Energy Technology Data Exchange (ETDEWEB)

    He, Qingyun, E-mail: hqingyun@mail.ustc.edu.cn; Feng, Jingchao; Chen, Hongli, E-mail: hlchen1@ustc.edu.cn

    2016-11-01

    Highlights: • MHD flows in rectangular U bends have been investigated under specific magnetic field. • U bends analyzed with different aspect ratio, distance of U bends and the wall conductance ratio. • Pressure optimization of rectangular U bends at corner region. • Studying different inclination of magnetic field cases according to original MHD flows. - Abstract: Liquid metal flow in rectangular bends is a common phenomenon of fusion liquid metal blanket operation, in which the velocity distributions and magnetohydrodynamic (MHD) pressure drop are considered as critical issues. Previous studies mainly aimed at specific fixed geometry for bend flows in LM blanket. The present investigation focuses on numerical analysis of MHD flow in 3D rectangular bends at laminar conditions, which is aimed to reduce MHD pressure drop caused by electromagnetic coupling in conductive flow, especially in bend corner region. The used code has been developed by University of Science and Technology of China (USTC) and validated by recommended benchmark cases such as Shercliff, ALEX experiments and KIT experiment cases, etc. In order to search the optimal duct bending, certain parameters such as different aspect ratio of the duct corner area cross-section, distance of import and export from the elbow and wall conductance ratio have been considered to investigate the pressure drop of MHD flow. Moreover, the effects of different magnetic field direction relative to flow distribution between bends have also been analyzed.

  3. Numerical analysis and optimization of 3D magnetohydrodynamic flows in rectangular U-bend

    International Nuclear Information System (INIS)

    He, Qingyun; Feng, Jingchao; Chen, Hongli

    2016-01-01

    Highlights: • MHD flows in rectangular U bends have been investigated under specific magnetic field. • U bends analyzed with different aspect ratio, distance of U bends and the wall conductance ratio. • Pressure optimization of rectangular U bends at corner region. • Studying different inclination of magnetic field cases according to original MHD flows. - Abstract: Liquid metal flow in rectangular bends is a common phenomenon of fusion liquid metal blanket operation, in which the velocity distributions and magnetohydrodynamic (MHD) pressure drop are considered as critical issues. Previous studies mainly aimed at specific fixed geometry for bend flows in LM blanket. The present investigation focuses on numerical analysis of MHD flow in 3D rectangular bends at laminar conditions, which is aimed to reduce MHD pressure drop caused by electromagnetic coupling in conductive flow, especially in bend corner region. The used code has been developed by University of Science and Technology of China (USTC) and validated by recommended benchmark cases such as Shercliff, ALEX experiments and KIT experiment cases, etc. In order to search the optimal duct bending, certain parameters such as different aspect ratio of the duct corner area cross-section, distance of import and export from the elbow and wall conductance ratio have been considered to investigate the pressure drop of MHD flow. Moreover, the effects of different magnetic field direction relative to flow distribution between bends have also been analyzed.

  4. Analysis of critical current-bend strain relationships in composite Nb3Sn superconducting wires

    International Nuclear Information System (INIS)

    Luhman, T.; Welch, D.O.

    1979-01-01

    In order to be used successfully in fusion magnets, Nb 3 Sn conductors must meet several mechanical strain criteria, including tolerance to bending strains encountered during magnet construction. Since Nb 3 Sn is extremely brittle much information has been generated regarding the sensitivity of these conductros to tensile strain. A recent comparison of critical current-bend and tensile test data indicates that the strain required to initiate compound cracking during bending is significantly less than the strain required to do so by tensile of critical current on bending strains in monofilamentary Nb 3 Sn wires is calculated and compared with experimental data. The calculation takes into account a shift in the composite's neutral axis which occurs during bending. The analysis correctly predicts the observed depdndence of the critical current on bending strains

  5. Failure analysis of re-bars during bending operations

    Directory of Open Access Journals (Sweden)

    Souvik Das

    2014-10-01

    Full Text Available Thermo-mechanical treated (TMT rebar is suitable material for reinforcing concrete structures on accounts of similarity in thermal expansion, ability to bond well with concrete and, above all the ability to shoulder most of the tensile stress acting on the structure and also steel manufacturing industry has successfully developed a corrosion-resistant variety of rebar for the construction industry. As the TMT is the finish product thus proper control of rolling parameters and water box is needed to achieve adequate property. Water box plays an important role for achieving the final structure and property of the rebars. Water box is responsible for outer rim formation and which helps to achieve the yield strength of the material. The present paper highlights failure investigation of a failed rebar during bending operations. From fractography and microstructural analysis it is confirmed that the rebar sample failed in brittle manner due to through harden martensitic structure and which indicates that there is some anomaly in water box resulting in these premature failures.

  6. Study of failure criterion applicable to elastic-plastic finite element analyses of wall-thinned pipes subjected to multi-axial loading. Case for groove type flaw under combined internal pressure and bending loading

    International Nuclear Information System (INIS)

    Mori, Kosuke; Meshii, Toshiyuki

    2015-01-01

    In this paper, a failure criterion applicable to large-strain finite element analysis (FEA) results was studied to predict the limit bending load M_c of the groove shaped wall-thinned pipes, under combined internal pressure and bending load, that experienced cracking. In our previous studies, Meshii and Ito (2012) considered cracking of pipes with groove shaped flaw (small axial length δ_z in Fig. 1) was due to the plastic instability at the wall-thinned section and proposed the Domain Collapse Criterion (DCC). The DCC could predict M_c of cracking for small δ_z by comparing the von Mises stress σ_M_i_s_e_s with the true tensile strength σ_B. Because the discrepancy in prediction of the M_c in the case of cracking was within 15%, it was considered that the predictability was could be improved further. Thus, in this work, attempt was made to improve the accuracy of M_c prediction with a perspective that multi-axial stress state might affect this plastic instability at the wall-thinned section. As a result of examination of the various failure criteria based on multi-axial stress, it was confirmed that the limit bending load of the groove flawed pipe that experienced cracking in experiment (Hereafter, it was expressed 'flawed pipe that experienced cracking') could be predicted within 5% accuracy by applying Hill's plastic instability onset criterion (Hill, 1952) to the outer surface of the crack penetration section. The accuracy of the predicted limit bending load was improved from DCC's within 15% to within 5%. (author)

  7. Flexibility analysis in adolescent idiopathic scoliosis on side-bending images using the EOS imaging system.

    Science.gov (United States)

    Hirsch, C; Ilharreborde, B; Mazda, K

    2016-06-01

    Analysis of preoperative flexibility in adolescent idiopathic scoliosis (AIS) is essential to classify the curves, determine their structurality, and select the fusion levels during preoperative planning. Side-bending x-rays are the gold standard for the analysis of preoperative flexibility. The objective of this study was to examine the feasibility and performance of side-bending images taken in the standing position using the EOS imaging system. All patients who underwent preoperative assessment between April 2012 and January 2013 for AIS were prospectively included in the study. The work-up included standing AP and lateral EOS x-rays of the spine, standard side-bending x-rays in the supine position, and standing bending x-rays in the EOS booth. The irradiation dose was measured for each of the tests. Two-dimensional reducibility of the Cobb angle was measured on both types of bending x-rays. The results were based on the 50 patients in the study. No significant difference was demonstrated for reducibility of the Cobb angle between the standing side-bending images with the EOS imaging system and those in the supine position for all types of Lenke deformation. The irradiation dose was five times lower during the EOS bending imaging. The standing side-bending images in the EOS device contributed the same results as the supine images, with five times less irradiation. They should therefore be used in clinical routine. 2. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  8. A Numerical Study of the Spring-Back Phenomenon in Bending with a Rebar Bending Machine

    Directory of Open Access Journals (Sweden)

    Chang Hwan Choi

    2014-10-01

    Full Text Available Recently, the rebar bending methodology started to change from field processing to utilizing rebar bending machines at plant sites prior to transport to the construction locations. Computerized control of rebar plant bending machines provides more accurate and faster bending of rebars than the low quality inefficient field processing alternative. The bending process involves plastic deformation of rebars, where bending stress beyond the yield point of the material is applied. When the bending stress is removed, spring back is caused by the elastic restoring stress. Therefore, an accurate numerical analysis of the spring-back process is required to reduce the bending process errors. The most sensitive factors affecting the spring-back process are the bending radius, the bending angle, the diameter of the rebar, the friction coefficient, and the yielding strength of material. In this paper, we suggest a numerical modeling method using these factors. The finite element modeling of the dynamic mechanical behavior of the material during bending is performed using a commercial dynamic analysis program “DAFUL.” We use the least squares approach to derive the spring-back deflection as a function of the rebar bending parameters.

  9. Effect of cross section on collapse load in pipe bends subjected to in ...

    African Journals Online (AJOL)

    user

    Also various researchers have estimated the plastic loads of pipe bends with cracks (Hong et al, ... In reality, the pipe bend exists with shape imperfections namely ovality and ... C t. −. = ×. (3). 3. Finite element limit analysis. Figure 1. Pipe bend with ..... Chattopadhyay J., Natahani D. K., Dutta B. K. and Kushwaha H. S. 2000.

  10. Numerical analysis of sandwich beam with corrugated core under three-point bending

    Energy Technology Data Exchange (ETDEWEB)

    Wittenbeck, Leszek [Poznan University of Technology, Institute of Mathematics Piotrowo Street No. 5, 60-965 Poznan (Poland); Grygorowicz, Magdalena; Paczos, Piotr [Poznan University of Technology, Institute of Applied Mechanics Jana Pawla IIStreet No. 24, 60-965 Poznan (Poland)

    2015-03-10

    The strength problem of sandwich beam with corrugated core under three-point bending is presented.The beam are made of steel and formed by three mutually orthogonal corrugated layers. The finite element analysis (FEA) of the sandwich beam is performed with the use of the FEM system - ABAQUS. The relationship between the applied load and deflection in three-point bending is considered.

  11. Elastic-plastic-creep analysis of shells

    International Nuclear Information System (INIS)

    Pai, D.H.

    1979-01-01

    This paper presents the recent experience of a designer/fabricator of nuclear heat transport components in the area of elastic-plastic-creep analysis of shell-like structures. A brief historical perspective is first given to highlight the evolution leading to the present industry practice. The ASME elevated temperature design criteria will be discussed followed by examples of actual computations performed to support the design/analysis and fabrication of a breeder reactor component in which a substantial amount of elastic-plastic-creep analysis was performed. Mathematical challenges encountered by the design analyst in these problems will be highlighted. Developmental needs and future trends will then be given

  12. Constitutive modeling and structural analysis considering simultaneous phase transformation and plastic yield in shape memory alloys

    Science.gov (United States)

    Hartl, D. J.; Lagoudas, D. C.

    2009-10-01

    The new developments summarized in this work represent both theoretical and experimental investigations of the effects of plastic strain generation in shape memory alloys (SMAs). Based on the results of SMA experimental characterization described in the literature and additional testing described in this work, a new 3D constitutive model is proposed. This phenomenological model captures both the conventional shape memory effects of pseudoelasticity and thermal strain recovery, and additionally considers the initiation and evolution of plastic strains. The model is numerically implemented in a finite element framework using a return mapping algorithm to solve the constitutive equations at each material point. This combination of theory and implementation is unique in its ability to capture the simultaneous evolution of recoverable transformation strains and irrecoverable plastic strains. The consideration of isotropic and kinematic plastic hardening allows the derivation of a theoretical framework capturing the interactions between irrecoverable plastic strain and recoverable strain due to martensitic transformation. Further, the numerical integration of the constitutive equations is formulated such that objectivity is maintained for SMA structures undergoing moderate strains and large displacements. The implemented model has been used to perform 3D analysis of SMA structural components under uniaxial and bending loads, including a case of local buckling behavior. Experimentally validated results considering simultaneous transformation and plasticity in a bending member are provided, illustrating the predictive accuracy of the model and its implementation.

  13. Constitutive modeling and structural analysis considering simultaneous phase transformation and plastic yield in shape memory alloys

    International Nuclear Information System (INIS)

    Hartl, D J; Lagoudas, D C

    2009-01-01

    The new developments summarized in this work represent both theoretical and experimental investigations of the effects of plastic strain generation in shape memory alloys (SMAs). Based on the results of SMA experimental characterization described in the literature and additional testing described in this work, a new 3D constitutive model is proposed. This phenomenological model captures both the conventional shape memory effects of pseudoelasticity and thermal strain recovery, and additionally considers the initiation and evolution of plastic strains. The model is numerically implemented in a finite element framework using a return mapping algorithm to solve the constitutive equations at each material point. This combination of theory and implementation is unique in its ability to capture the simultaneous evolution of recoverable transformation strains and irrecoverable plastic strains. The consideration of isotropic and kinematic plastic hardening allows the derivation of a theoretical framework capturing the interactions between irrecoverable plastic strain and recoverable strain due to martensitic transformation. Further, the numerical integration of the constitutive equations is formulated such that objectivity is maintained for SMA structures undergoing moderate strains and large displacements. The implemented model has been used to perform 3D analysis of SMA structural components under uniaxial and bending loads, including a case of local buckling behavior. Experimentally validated results considering simultaneous transformation and plasticity in a bending member are provided, illustrating the predictive accuracy of the model and its implementation

  14. Finite element analysis of a finite-strain plasticity problem

    International Nuclear Information System (INIS)

    Crose, J.G.; Fong, H.H.

    1984-01-01

    A finite-strain plasticity analysis was performed of an engraving process in a plastic rotating band during the firing of a gun projectile. The aim was to verify a nonlinear feature of the NIFDI/RB code: plastic large deformation analysis of nearly incompressible materials using a deformation theory of plasticity approach and a total Lagrangian scheme. (orig.)

  15. A comparison of time-history elastic plastic piping analysis with measurement

    International Nuclear Information System (INIS)

    Scavuzzo, R.J.; Sansalone, K.H.

    1992-01-01

    The GE/ETEC Green piping system was subjected to high seismic inputs from hydraulic sleds at each pipe foundation. These inputs were high enough to force bending stresses into the plastic regime. Strain gages recorded the pipe response at various positions within the system. The ABAQUS finite element code was used to model this piping system and the dynamic input. Problems associated with the dynamic input are discussed. Various types of finite elements were evaluated for accurancy. Both an elastic time-history analysis and an elastic-plastic time-history analysis of the system were conducted. Results of these analyses are compared to each other and the experimental data. These comparisons indicated that elastic analysis of dynamic strains are conservative at all points of comparison and that there is good agreement between the nonlinear elastic-plastic analysis and experimental data. (orig.)

  16. Stress analysis of feeder bends using neutrons: new results and cumulative impacts

    Energy Technology Data Exchange (ETDEWEB)

    Banks, D.; Donaberger, R. [Canadian Neutron Beam Centre, Chalk River, ON (Canada); Leitch, B. [Atomic Energy of Canada Limited, Chalk River, ON (Canada); Rogge, R.B. [Canadian Neutron Beam Centre, Chalk River, ON (Canada)

    2014-07-01

    Neutron diffraction has played a vital role in stress analysis of bends in carbon steel pipes, known as feeder pipes, in CANDU reactors. Due to incidents of cracking of feeders, extensive R&D programs to manage feeder cracking have been implemented over about ten years. We review the cumulative impacts of this research from the view point of the stress analysis using neutrons, and present new results by examining a feeder bend with a partial crack both experimentally using neutron diffraction and theoretically using a finite element model. (author)

  17. Analysis of pipe mitred bends using beam models - by finite element method

    International Nuclear Information System (INIS)

    Salles, A.C.S.L. de.

    1984-01-01

    The formulation of a recently proposed displacement based straight pipe element for the analysis of pipe mitred bends is summarized in this work. The element kinematics includes axial, bending, torsional and ovalisation displacements, all varying cubically along the axis of the element. Interaction effects between angle adjoined straight pipe section are modeled including the appropriate additional strain terms in the stiffness matrix formulation and by using a penalty procedure to enforce continuity of pipe skin flexural rotations at the common helical edge. The element model capabilities are ilustrated in some sample analysis and the results are compared with other available experimental, analytical or more complex numerical models. (Author) [pt

  18. Plastic

    International Nuclear Information System (INIS)

    Jeong Gi Hyeon

    1987-04-01

    This book deals with plastic, which includes introduction for plastic, chemistry of high polymers, polymerization, speciality and structure of a high molecule property of plastic, molding, thermosetting plastic, such as polyethylene, polyether, polyamide and polyvinyl acetyl, thermal plastic like phenolic resins, xylene resins, melamine resin, epoxy resin, alkyd resin and poly urethan resin, new plastic like ionomer and PPS resin, synthetic laminated tape and synthetic wood, mixed materials in plastic, reprocessing of waste plastic, polymer blend, test method for plastic materials and auxiliary materials of plastic.

  19. Statistical Analysis of Bending Rigidity Coefficient Determined Using Fluorescence-Based Flicker-Noise Spectroscopy.

    Science.gov (United States)

    Doskocz, Joanna; Drabik, Dominik; Chodaczek, Grzegorz; Przybyło, Magdalena; Langner, Marek

    2018-06-01

    Bending rigidity coefficient describes propensity of a lipid bilayer to deform. In order to measure the parameter experimentally using flickering noise spectroscopy, the microscopic imaging is required, which necessitates the application of giant unilamellar vesicles (GUV) lipid bilayer model. The major difficulty associated with the application of the model is the statistical character of GUV population with respect to their size and the homogeneity of lipid bilayer composition, if a mixture of lipids is used. In the paper, the bending rigidity coefficient was measured using the fluorescence-enhanced flicker-noise spectroscopy. In the paper, the bending rigidity coefficient was determined for large populations of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and 1,2-dioleoyl-sn-glycero-3-phosphocholine vesicles. The quantity of obtained experimental data allows to perform statistical analysis aiming at the identification of the distribution, which is the most appropriate for the calculation of the value of the membrane bending rigidity coefficient. It has been demonstrated that the bending rigidity coefficient is characterized by an asymmetrical distribution, which is well approximated with the gamma distribution. Since there are no biophysical reasons for that we propose to use the difference between normal and gamma fits as a measure of the homogeneity of vesicle population. In addition, the effect of a fluorescent label and types of instrumental setups on determined values has been tested. Obtained results show that the value of the bending rigidity coefficient does not depend on the type of a fluorescent label nor on the type of microscope used.

  20. Simplified method for the transverse bending analysis of twin celled concrete box girder bridges

    Science.gov (United States)

    Chithra, J.; Nagarajan, Praveen; S, Sajith A.

    2018-03-01

    Box girder bridges are one of the best options for bridges with span more than 25 m. For the study of these bridges, three-dimensional finite element analysis is the best suited method. However, performing three-dimensional analysis for routine design is difficult as well as time consuming. Also, software used for the three-dimensional analysis are very expensive. Hence designers resort to simplified analysis for predicting longitudinal and transverse bending moments. Among the many analytical methods used to find the transverse bending moments, SFA is the simplest and widely used in design offices. Results from simplified frame analysis can be used for the preliminary analysis of the concrete box girder bridges.From the review of literatures, it is found that majority of the work done using SFA is restricted to the analysis of single cell box girder bridges. Not much work has been done on the analysis multi-cell concrete box girder bridges. In this present study, a double cell concrete box girder bridge is chosen. The bridge is modelled using three- dimensional finite element software and the results are then compared with the simplified frame analysis. The study mainly focuses on establishing correction factors for transverse bending moment values obtained from SFA.

  1. Experimental and numerical investigation on laser-assisted bending of pre-loaded metal plate

    Science.gov (United States)

    Nowak, Zdzisław; Nowak, Marcin; Widłaszewski, Jacek; Kurp, Piotr

    2018-01-01

    The laser forming technique has an important disadvantage, which is the limitation of plastic deformation generated by a single laser beam pass. To increase the plastic deformation it is possible to apply external forces in the laser forming process. In this paper, we investigate the influence of external pre-loads on the laser bending of steel plate. The pre-loads investigated generate bending towards the laser beam. The thermal, elastic-plastic analysis is performed using the commercial nonlinear finite element analysis package ABAQUS. The focus of the paper is to identify how this pattern of the pre-load influence the final bend angle of the plate.

  2. In-situ bending under tension shear fracture analysis and microstructure “earthquake” of DP780 dual phase steels

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yixi, E-mail: yxzhao@sjtu.edu.cn [State Key Laboratory of Mechanical System and Vibration, Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, Shanghai Jiao Tong University, Shanghai 200240 (China); Huang, Sheng [State Key Laboratory of Mechanical System and Vibration, Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, Shanghai Jiao Tong University, Shanghai 200240 (China); Dan, Wenjiao; Zhang, Weigang [Innovation Center for Advanced Ship and Deep-Sea Exploration, Department of Engineering Mechanics, Shanghai Jiao Tong University, Shanghai 200240 (China); Li, Shuhui [State Key Laboratory of Mechanical System and Vibration, Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2017-05-17

    Dual phase (DP) steels consist of hard brittle martensite phase and soft ductile ferrite phase. With a novel bending under tension test system, in-situ symmetrical bending under tension experiments were carried out and photomicrographs of bending surface were recorded. The microstructure “earthquake” of DP780 dual phase steels was observed in the bending under tension process. By analyzing the in-situ images serious, the initiation, coalescence of cavities and propagation of micro-cracks until final fracture were analyzed. The micro-cracks form only in the outside surface of bending radius, and mainly appear near the phase boundary of ferrite and martensite. Micro-cracks coalesce and propagate in the direction perpendicular to the stretching direction approximately, and at the phase boundary of martensite and ferrite. Furthermore, digital image correlation technology was used in this study to analysis the strain distribution between ferrite and martensite during the bending under tension deformation and fracture.

  3. Thermodynamic analysis of elastic-plastic deformation

    International Nuclear Information System (INIS)

    Lubarda, V.

    1981-01-01

    The complete set of constitutive equations which fully describes the behaviour of material in elastic-plastic deformation is derived on the basis of thermodynamic analysis of the deformation process. The analysis is done after the matrix decomposition of the deformation gradient is introduced into the structure of thermodynamics with internal state variables. The free energy function, is decomposed. Derive the expressions for the stress response, entropy and heat flux, and establish the evolution equation. Finally, we establish the thermodynamic restrictions of the deformation process. (Author) [pt

  4. Coupling between shear and bending in the analysis of beam problems: Planar case

    Science.gov (United States)

    Shabana, Ahmed A.; Patel, Mohil

    2018-04-01

    The interpretation of invariants, such as curvatures which uniquely define the bending and twist of space curves and surfaces, is fundamental in the formulation of the beam and plate elastic forces. Accurate representations of curve and surface invariants, which enter into the definition of the strain energy equations, is particularly important in the case of large displacement analysis. This paper discusses this important subject in view of the fact that shear and bending are independent modes of deformation and do not have kinematic coupling; this is despite the fact that kinetic coupling may exist. The paper shows, using simple examples, that shear without bending and bending without shear at an arbitrary point and along a certain direction are scenarios that higher-order finite elements (FE) can represent with a degree of accuracy that depends on the order of interpolation and/or mesh size. The FE representation of these two kinematically uncoupled modes of deformation is evaluated in order to examine the effect of the order of the polynomial interpolation on the accuracy of representing these two independent modes. It is also shown in this paper that not all the curvature vectors contribute to bending deformation. In view of the conclusions drawn from the analysis of simple beam problems, the material curvature used in several previous investigations is evaluated both analytically and numerically. The problems associated with the material curvature matrix, obtained using the rotation of the beam cross-section, and the fundamental differences between this material curvature matrix and the Serret-Frenet curvature matrix are discussed.

  5. Nonlinear bending and collapse analysis of a poked cylinder and other point-loaded cylinders

    International Nuclear Information System (INIS)

    Sobel, L.H.

    1983-06-01

    This paper analyzes the geometrically nonlinear bending and collapse behavior of an elastic, simply supported cylindrical shell subjected to an inward-directed point load applied at midlength. The large displacement analysis results for this thin (R/t = 638) poked cylinder were obtained from the STAGSC-1 finite element computer program. STAGSC-1 results are also presented for two other point-loaded shell problems: a pinched cylinder (R/t = 100), and a venetian blind (R/t = 250)

  6. Vesicle fluctuation analysis of the effects of sterols on membrane bending rigidity

    DEFF Research Database (Denmark)

    Henriksen, Jonas Rosager; Rowat, Amy C.; Ipsen, John H.

    2004-01-01

    Sterols are regulators of both biological function and structure. The role of cholesterol in promoting the structural and mechanical stability of membranes is widely recognized. Knowledge of how the related sterols, lanosterol and ergosterol, affect membrane mechanical properties is sparse. This ...... on vesicle behaviour are also discussed. These recent modifications render vesicle fluctuation analysis an efficient and accurate method for determining how cholesterol, lanosterol, and ergosterol increase membrane bending rigidity....

  7. A contribution for stress analysis in bend acessories of piping systems

    International Nuclear Information System (INIS)

    Melo, F.J.M.Q. de; Castro, P.M.S.T. de

    1986-01-01

    Analytical and numerical studies of the linear elastic behavior of bend pipes, with tangent pipes or flanged ends, such as used in nuclear power plants are presented. Two analytical techniques were developed; one is based on the integration of Euler equation and the other one is based on a Fourier analysis. The results obtained using these approaches are compared with results obtained by a finite element code for 'semiloof shells. (Author) [pt

  8. Study on elastic-plastic deformation analysis using a cyclic stress-strain curve

    International Nuclear Information System (INIS)

    Igari, Toshihide; Setoguchi, Katsuya; Yamauchi, Masafumi

    1983-01-01

    This paper presents the results of the elastic-plastic deformation analysis using a cyclic stress-strain curve with an intention to apply this method for predicting the low-cycle fatigue life. Uniaxial plastic cycling tests were performed on 2 1/4Cr-1Mo steel to investigate the correspondence between the cyclic stress-strain curve and the hysteresis loop, and also to determine what mathematical model should be used for analysis of deformation at stress reversal. Furthermore, a cyclic in-plane bending test was performed on a flat plate to clarify the validity of the cyclic stress-strain curve-based theoretical analysis. The results obtained are as follows: (1) The cyclic stress-strain curve corresponds nearly to the ascending curve of hysteresis loop scaled by a factor of 1/2 for both stress and strain. Therefore, the cyclic stress-strain curve can be determined from the shape of hysteresis loop, for simplicity. (2) To perform the elastic-plastic deformation analysis using the cyclic stress-strain curve is both practical and effective for predicting the cyclic elastic-plastic deformation of structures at the stage of advanced cycles. And Masing model can serve as a suitable mathematical model for such a deformation analysis. (author)

  9. Weibull statistical analysis of Krouse type bending fatigue of nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Haidyrah, Ahmed S., E-mail: ashdz2@mst.edu [Nuclear Engineering, Missouri University of Science & Technology, 301 W. 14th, Rolla, MO 65409 (United States); Nuclear Science Research Institute, King Abdulaziz City for Science and Technology (KACST), P.O. Box 6086, Riyadh 11442 (Saudi Arabia); Newkirk, Joseph W. [Materials Science & Engineering, Missouri University of Science & Technology, 1440 N. Bishop Ave, Rolla, MO 65409 (United States); Castaño, Carlos H. [Nuclear Engineering, Missouri University of Science & Technology, 301 W. 14th, Rolla, MO 65409 (United States)

    2016-03-15

    A bending fatigue mini-specimen (Krouse-type) was used to study the fatigue properties of nuclear materials. The objective of this paper is to study fatigue for Grade 91 ferritic-martensitic steel using a mini-specimen (Krouse-type) suitable for reactor irradiation studies. These mini-specimens are similar in design (but smaller) to those described in the ASTM B593 standard. The mini specimen was machined by waterjet and tested as-received. The bending fatigue machine was modified to test the mini-specimen with a specially designed adapter. The cycle bending fatigue behavior of Grade 91 was studied under constant deflection. The S–N curve was created and mean fatigue life was analyzed using mean fatigue life. In this study, the Weibull function was predicted probably for high stress to low stress at 563, 310 and 265 MPa. The commercial software Minitab 17 was used to calculate the distribution of fatigue life under different stress levels. We have used 2 and 3- parameters Weibull analysis to introduce the probability of failure. The plots indicated that the 3- parameter Weibull distribution fits the data well.

  10. Weibull statistical analysis of Krouse type bending fatigue of nuclear materials

    International Nuclear Information System (INIS)

    Haidyrah, Ahmed S.; Newkirk, Joseph W.; Castaño, Carlos H.

    2016-01-01

    A bending fatigue mini-specimen (Krouse-type) was used to study the fatigue properties of nuclear materials. The objective of this paper is to study fatigue for Grade 91 ferritic-martensitic steel using a mini-specimen (Krouse-type) suitable for reactor irradiation studies. These mini-specimens are similar in design (but smaller) to those described in the ASTM B593 standard. The mini specimen was machined by waterjet and tested as-received. The bending fatigue machine was modified to test the mini-specimen with a specially designed adapter. The cycle bending fatigue behavior of Grade 91 was studied under constant deflection. The S–N curve was created and mean fatigue life was analyzed using mean fatigue life. In this study, the Weibull function was predicted probably for high stress to low stress at 563, 310 and 265 MPa. The commercial software Minitab 17 was used to calculate the distribution of fatigue life under different stress levels. We have used 2 and 3- parameters Weibull analysis to introduce the probability of failure. The plots indicated that the 3- parameter Weibull distribution fits the data well.

  11. A New Kind of Bend Sensor

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new kind of bend sensor is introduced.It can be used to detect the bend angle of an object or inclination between two objects.It has characteristics of small size, lightweight, high reliability, fine flexibility and plasticity.When this bend sensor is used with a proper converting circuit, it can implement dynamic measuring the bend angle of an object conveniently.The application of the bend sensor in dataglove is also described.

  12. Bending behaviors of fully covered biodegradable polydioxanone biliary stent for human body by finite element method.

    Science.gov (United States)

    Liu, Yanhui; Zhu, Guoqing; Yang, Huazhe; Wang, Conger; Zhang, Peihua; Han, Guangting

    2018-01-01

    This paper presents a study of the bending flexibility of fully covered biodegradable polydioxanone biliary stents (FCBPBs) developed for human body. To investigate the relationship between the bending load and structure parameter (monofilament diameter and braid-pin number), biodegradable polydioxanone biliary stents derived from braiding method were covered with membrane prepared via electrospinning method, and nine FCBPBSs were then obtained for bending test to evaluate the bending flexibility. In addition, by the finite element method, nine numerical models based on actual biliary stent were established and the bending load was calculated through the finite element method. Results demonstrate that the simulation and experimental results are in good agreement with each other, indicating that the simulation results can be provided a useful reference to the investigation of biliary stents. Furthermore, the stress distribution on FCBPBSs was studied, and the plastic dissipation analysis and plastic strain of FCBPBSs were obtained via the bending simulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Analysis of bending process using forming simulation; Seikei simulation ni yoru press niji seikei kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Hamaguchi, T; Ogawa, T; Tamai, H [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    FEM simulation system is becoming an effective tool in the production engineering, especially in the evaluation of press formability. We have been applying it to the evaluation of defect phenomena, such as breakage and wrinkling, which occur in the drawing process to produce auto body parts. We tried a new application which treat dimensional precision and the other defect in the flanging or bending process after trimming. In this paper, we introduced the result of development and an example applied in the analysis. 1 refs., 8 figs.

  14. Quasi-static analysis and control of planer and spatial bending fluidic actuator

    OpenAIRE

    Chang, Benjamin Che-Ming

    2011-01-01

    This work presents a novel silicone-based millimetre scale bending fluidic actuator. Two designs of the bending fluidic actuator are studied: a planer actuator that bends about one axis; and a spatial actuator able to bend about two orthogonal axes. The unique parallel micro-channel design of the fluidic actuators enables operation at low working pressures, while at the same time having a very limited thickness expansion during pressurization. The fluidic actuators can be easily scaled to des...

  15. Thermo-plastic finite element analysis for metal honeycomb structure

    Directory of Open Access Journals (Sweden)

    Ji Zhanling

    2013-01-01

    Full Text Available This paper deals with thermal-plastic analysis for the metal honeycomb structure. The heat transfer equation and thermal elastoplastic constitutive equation of a multilayer panel are established and studied numerically using ANSYS software. The paper elucidates that only the outer skin produces easily plastic deformation, and the outer skin still exists some residual stress and residual deformation after cooling. The dynamic evolution of plastic deformation and material performance degradation under high energy thermal load are revealed.

  16. Calculation methods' comparative analysis of monorail hoist crane local bending effects

    Directory of Open Access Journals (Sweden)

    Cvijović Goran M.

    2016-01-01

    Full Text Available The results of numerical and experimental researches of local bending problems, carried on classic and medium-wide I profiles, were a basis for the adoption of the current standards (EN 15011: 2014 which regulates the action of the local stress caused by the effect of cart wheels. Regarding the fact that IPB (HE-B wide flange profiles are largely used for production of the main carriers of monorail transport systems, this paper presents the results of the action of the local stress caused by the effect of cart wheels on the HE-A flange profile, using the methods and procedures of relevant researchers, the procedures prescribed by the standard EN 15011 as well as the results of calculations using finite element method. It has been revealed, based on comparative analysis of the results, that in the transition zone low flange / rib longitudinal local stress on the lower contour flange, determined using the above mentioned standards have tightening characteristic, while all other methods, including finite element method, give the pressing nature of the considered voltage. In addition, all of these procedures, except for the finite element method, adopt the assumption that absolute value of voltage, caused by local bending on upper and lower contour of the loaded flange, are the same, and there is no physical justification. Bearing in mind the fact that stress identification, caused by the flange local bending, is an extremely important phase proving the strength of monorail beams, we may conclude that the application of standard EN 15011 does not provide reliable results when it comes to wide flange profiles.

  17. Accuracy and reproducibility of bending stiffness measurements by mechanical response tissue analysis in artificial human ulnas.

    Science.gov (United States)

    Arnold, Patricia A; Ellerbrock, Emily R; Bowman, Lyn; Loucks, Anne B

    2014-11-07

    Osteoporosis is characterized by reduced bone strength, but no FDA-approved medical device measures bone strength. Bone strength is strongly associated with bone stiffness, but no FDA-approved medical device measures bone stiffness either. Mechanical Response Tissue Analysis (MRTA) is a non-significant risk, non-invasive, radiation-free, vibration analysis technique for making immediate, direct functional measurements of the bending stiffness of long bones in humans in vivo. MRTA has been used for research purposes for more than 20 years, but little has been published about its accuracy. To begin to investigate its accuracy, we compared MRTA measurements of bending stiffness in 39 artificial human ulna bones to measurements made by Quasistatic Mechanical Testing (QMT). In the process, we also quantified the reproducibility (i.e., precision and repeatability) of both methods. MRTA precision (1.0±1.0%) and repeatability (3.1 ± 3.1%) were not as high as those of QMT (0.2 ± 0.2% and 1.3+1.7%, respectively; both pstiffness was indistinguishable from the identity line (p=0.44) and paired measurements by the two methods agreed within a 95% confidence interval of ± 5%. If such accuracy can be achieved on real human ulnas in situ, and if the ulna is representative of the appendicular skeleton, MRTA may prove clinically useful. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Effect of reinforcement on plastic limit loads of branch junctions

    International Nuclear Information System (INIS)

    Kim, Yun-Jae; Myeong, Man-Sik; Yoon, Kee-Bong

    2009-01-01

    This paper provides effects of reinforcement shape and area on plastic limit loads of branch junctions under internal pressure and in-plane/out-of-plane bending, via detailed three-dimensional finite element limit analysis assuming elastic-perfectly plastic material behaviour. It is found that reinforcement is most effective when (in-plane/out-of-plane) bending is applied to the branch pipe. When bending is applied to the run pipe, reinforcement is less effective when bending is applied to the branch pipe. The reinforcement effect is the least effective for internal pressure.

  19. TERAHERTZ SPECTROSCOPY AND GLOBAL ANALYSIS OF THE BENDING VIBRATIONS OF ACETYLENE 12C2D2

    International Nuclear Information System (INIS)

    Yu Shanshan; Drouin, Brian J.; Pearson, John C.; Pickett, Herbert M.; Lattanzi, Valerio; Walters, Adam

    2009-01-01

    Two hundred and fifty-one 12 C 2 D 2 transitions have been measured in the 0.2-1.6 THz region of its ν 5 -ν 4 difference band and 202 of them were observed for the first time. The accuracy of these measurements is estimated to be ranging from 50 kHz to 100 kHz. The 12 C 2 D 2 molecules were generated under room temperature by passing 120-150 mTorr D 2 O vapor through calcium carbide (CaC 2 ) powder. A multistate analysis was carried out for the bending vibrational modes ν 4 and ν 5 of 12 C 2 D 2 , which includes the lines observed in this work and prior microwave, far-infrared and infrared data on the pure bending levels. Significantly improved molecular parameters were obtained for 12 C 2 D 2 by adding the new measurements to the old data set, which had only 10 lines with microwave measurement precision. New frequency and intensity predictions have been made based on the obtained molecular parameters. The more precise measurements and new predictions reported here will support the analyses of astronomical observations by the future high-resolution spectroscopy telescopes such as Herschel, SOFIA, and ALMA, which will work in the terahertz spectral region.

  20. Comparative Analysis of Soft Computing Models in Prediction of Bending Rigidity of Cotton Woven Fabrics

    Science.gov (United States)

    Guruprasad, R.; Behera, B. K.

    2015-10-01

    Quantitative prediction of fabric mechanical properties is an essential requirement for design engineering of textile and apparel products. In this work, the possibility of prediction of bending rigidity of cotton woven fabrics has been explored with the application of Artificial Neural Network (ANN) and two hybrid methodologies, namely Neuro-genetic modeling and Adaptive Neuro-Fuzzy Inference System (ANFIS) modeling. For this purpose, a set of cotton woven grey fabrics was desized, scoured and relaxed. The fabrics were then conditioned and tested for bending properties. With the database thus created, a neural network model was first developed using back propagation as the learning algorithm. The second model was developed by applying a hybrid learning strategy, in which genetic algorithm was first used as a learning algorithm to optimize the number of neurons and connection weights of the neural network. The Genetic algorithm optimized network structure was further allowed to learn using back propagation algorithm. In the third model, an ANFIS modeling approach was attempted to map the input-output data. The prediction performances of the models were compared and a sensitivity analysis was reported. The results show that the prediction by neuro-genetic and ANFIS models were better in comparison with that of back propagation neural network model.

  1. Elastic-plastic analysis of AS4/PEEK composite laminate using a one-parameter plasticity model

    Science.gov (United States)

    Sun, C. T.; Yoon, K. J.

    1992-01-01

    A one-parameter plasticity model was shown to adequately describe the plastic deformation of AS4/PEEK (APC-2) unidirectional thermoplastic composite. This model was verified further for unidirectional and laminated composite panels with and without a hole. The elastic-plastic stress-strain relations of coupon specimens were measured and compared with those predicted by the finite element analysis using the one-parameter plasticity model. The results show that the one-parameter plasticity model is suitable for the analysis of elastic-plastic deformation of AS4/PEEK composite laminates.

  2. Bending Distortion Analysis of a Steel Shaft Manufacturing Chain from Cold Drawing to Grinding

    Science.gov (United States)

    Dias, Vinicius Waechter; da Silva Rocha, Alexandre; Zottis, Juliana; Dong, Juan; Epp, Jérémy; Zoch, Hans Werner

    2017-04-01

    Shafts are usually manufactured from bars that are cold drawn, cut machined, induction hardened, straightened, and finally ground. The main distortion is characterized by bending that appears after induction hardening and is corrected by straightening and/or grinding. In this work, the consequence of the variation of manufacturing parameters on the distortion was analyzed for a complete manufacturing route for production of induction hardened shafts made of Grade 1045 steel. A DoE plan was implemented varying the drawing angle, cutting method, induction hardening layer depth, and grinding penetration depth. The distortion was determined by calculating curvature vectors from dimensional analysis by 3D coordinate measurements. Optical microscopy, microhardness testing, residual stress analysis, and FEM process simulation were used to evaluate and understand effects of the main carriers of distortion potential. The drawing process was identified as the most significant influence on the final distortion of the shafts.

  3. Numerical Analysis of AHSS Fracture in a Stretch-bending Test

    Science.gov (United States)

    Luo, Meng; Chen, Xiaoming; Shi, Ming F.; Shih, Hua-Chu

    2010-06-01

    Advanced High Strength Steels (AHSS) are increasingly used in the automotive industry due to their superior strength and substantial weight reduction advantage. However, their limited ductility gives rise to numerous manufacturing issues. One of them is the so-called `shear fracture' often observed on tight radii during stamping processes. Since traditional approaches, such as the Forming Limit Diagram (FLD), are unable to predict this type of fracture, efforts have been made to develop failure criteria that can predict shear fractures. In this paper, a recently developed Modified Mohr-Coulomb (MMC) ductile fracture criterion[1] is adopted to analyze the failure behavior of a Dual Phase (DP) steel sheet during stretch bending operations. The plasticity and ductile fracture of the present sheet are fully characterized by the Hill'48 orthotropic model and the MMC fracture model respectively. Finite Element models with three different element types (3D, shell and plane strain) were built for a Stretch Forming Simulator (SFS) test and numerical simulations with four different R/t ratios (die radius normalized by sheet thickness) were performed. It has been shown that the 3D and shell element models can accurately predict the failure location/mode, the upper die load-displacement responses as well as the wall stress and wrap angle at the onset of fracture for all R/t ratios. Furthermore, a series of parametric studies were conducted on the 3D element model, and the effects of tension level (clamping distance) and tooling friction on the failure modes/locations were investigated.

  4. MHD flow in multichannel U-bends: Screening experiments and theoretical analysis

    International Nuclear Information System (INIS)

    Reimann, J.; Molokov, S.; Platnieks, I.; Platacis, E.

    1993-02-01

    In electrically coupled multichannel ducts with a U-bend geometry magnetohydrodynamic effects are expected to cause strongly ununiform distributions of flow rates Q i and pressure drops Δp i in the individual channels. A multichannel U-bend geometry is part of the KfK self-cooled Pb-17 Li blanket design (radial-toroidal-radial channels). However, inserts are proposed which isolate electrically the radial channels (not the toroidal ones). To investigate the multichannel effect (MCE), screening experiments were performed at LAS, Riga, with different flow channel geometries and channel numbers between 1 and 5 and using InGaSn as liquid metal. These experiments were carried out with either Δp i ∼const or Q i ∼const. Hartmann Numbers were varied between 0 and ∼1600 (maximum magnetic field strength: 4.1 T) and Interaction Parameters between 0 and 10000. For experiments with electrically conducting walls between the channels, the volume flow rates in the outer channels are significantly larger than those in the inner channels in the experiments with Δp i ∼const. For Q i ∼const., this tendency is reversed, with the highest pressure drop in the middle channel and the lowest in the outer channels. The flow geometry with electrically separated radial channels, similar to the KfK-design result in a fairly even flow rate and pressure drop distribution. The single channels behave approximately like electrically separated channels; no marked MCE occurrs. A theoretical analysis was carried out to describe the MCE for the multichannel U-bend with thin electrically conducting outside walls. This analysis is based on the Core Flow Approximation (CFA), valid for infinitely large Interaction Parameters and Hartmann Numbers. The theory predicts correctly all tendencies observed for the pressure measurements. Moreover, the method is able to describe in detail the flow structure in the toroidal channel. The most essential result is that the flow rate in the layer close to the

  5. Modal analysis of blade bending and torsional shaft coupling by component mode synthesis

    International Nuclear Information System (INIS)

    Vare, C.

    1995-10-01

    The Acoustics and Vibration Mechanics Branch of EDF's Research and Development Division is in charge of performing finite element calculations, for the study of the vibratory behaviour of nuclear components. Due to the size and the geometrical complexity of some of these components, EDF has developed sub-structure synthesis methods for modal analysis of large structures. Both Craig-Bampton's and Mac Neal's methods have been implemented in the general mechanics code of EDF: the Aster Code. Craig-Bampton sub-structure synthesis approach was used to study the coupling between blade bending and torsional shaft of a turbine generator set. Four sub-structures were defined to make the calculation: a generator, a low pressure rotor, a high pressure rotor and a blade. The results of the modal calculation, show good agreement with the experimental measurements (error < 1 %). It shows the accuracy of component mode synthesis methods. (author). 6 refs., 7 figs

  6. Remeshing in analysis of large plastic deformations

    DEFF Research Database (Denmark)

    Pedersen, Thomas Ø

    1998-01-01

    Very distorted elements in a finite element computation will affect the results in a negative way. In applications where large plastic deformations are present, the mesh often deteriorates so badly, that remeshing is the only option to avoid a breakdown in the numerical computations. In the present...

  7. Experimental analysis of plastic materials containing radionuclides for decontamination viability

    International Nuclear Information System (INIS)

    Tazaki, Kazue; Nakano, Mikio; Takehara, Teruaki; Ishigaki, Yasuhito; Nakagawa, Hideaki

    2015-01-01

    After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on 11 March, 2011, the high radioactive dosage was found in polluted water for agriculture use at Baba, Haramachi, Minami-Soma, Fukushima Prefecture, Japan. Field experiment for decontamination of water had been studied by using commercial plastic materials. The agricultural water comes from Tetsuzan dam is full of radioactive-contaminated water. Experimental analysis showed that the plastic materials can take up radioactive elements for several months soaked in the polluted agricultural water. The quantitative analyses using X-ray fluorescence analysis, Ge semiconductor and scanning electron microscopy equipped with energy dispersive X-ray spectrometer (SEM-EDS), revealed the detection of the radionuclides on the plastic materials with diatom and clays. The results suggest the adsorption of radionuclides on the surface of plastic materials due to FDNPP accident. The plastic materials associated with clays and diatoms could be stronger carriers of radionuclides in the polluted water. Adherence of diatoms to the plastic fiber in the water for 7 months suggested that some plastic materials were taking up heavy metals (Zn, Ba, Pb, Sb) with radioactive elements (Cs etc.). Mechanisms by which radioactive pollutants and microorganisms are adsorbed onto and desorbed from clays at aqueous interface can be understood by combining chemical analysis with electron microscopy observation. (author)

  8. Numerical Analysis of Damage Iinitiation and Development in Bends of Steel Pipelines

    NARCIS (Netherlands)

    Swart, A.E.

    2010-01-01

    Gasses and fluids are transported via an extensive infrastructure of steel pipelines. In the design of pipeline systems the use of elbows (pipe bends) is important because their flexibility makes them able to sustain significant deformations. These bends can be subjected to permanent deformations

  9. Analysis of Variscan dynamics; early bending of the Cantabria-Asturias Arc, northern Spain

    Science.gov (United States)

    Kollmeier, J. M.; van der Pluijm, B. A.; Van der Voo, R.

    2000-08-01

    Calcite twinning analysis in the Cantabria-Asturias Arc (CAA) of northern Spain provides a basis for evaluating conditions of Variscan stress and constrains the arc's structural evolution. Twinning typically occurs during earliest layer-parallel shortening, offering the ability to define early conditions of regional stress. Results from the Somiedo-Correcilla region are of two kinds: early maximum compressive stress oriented layer-parallel and at high angles to bedding strike (D1 σ1) and later twin producing compression oriented sub-parallel to strike (D2 σ1). When all D1 compressions are rotated into a uniform east-west reference orientation, a quite linear, north-south trending fold-thrust belt results showing a slight deflection of the southern zone to the south-southeast. North-south-directed D2 σ1 compression was recorded prior to bending of the belt. Calcite twinning data elucidate earliest structural conditions that could not be obtained by other means, whereas the kinematics of arc tightening during D2 is constrained by paleomagnetism. A large and perhaps protracted D2 σ1 is suggested by our results, as manifested by approximately 50% arc tightening prior to acquisition of paleomagnetic remagnetizations throughout the CAA. Early east-west compression (D1 σ1) likely resulted from the Ebro-Aquitaine massif docking to Laurussia whereas the north-directed collision of Africa (D2 σ1) produced clockwise bending in the northern zone, radial folding in the hinge, and rotation of thrusts in the southern zone.

  10. Nonlinear Progressive Collapse Analysis Including Distributed Plasticity

    Directory of Open Access Journals (Sweden)

    Mohamed Osama Ahmed

    2016-01-01

    Full Text Available This paper demonstrates the effect of incorporating distributed plasticity in nonlinear analytical models used to assess the potential for progressive collapse of steel framed regular building structures. Emphasis on this paper is on the deformation response under the notionally removed column, in a typical Alternate Path (AP method. The AP method employed in this paper is based on the provisions of the Unified Facilities Criteria – Design of Buildings to Resist Progressive Collapse, developed and updated by the U.S. Department of Defense [1]. The AP method is often used for to assess the potential for progressive collapse of building structures that fall under Occupancy Category III or IV. A case study steel building is used to examine the effect of incorporating distributed plasticity, where moment frames were used on perimeter as well as the interior of the three dimensional structural system. It is concluded that the use of moment resisting frames within the structural system will enhance resistance to progressive collapse through ductile deformation response and that it is conserative to ignore the effects of distributed plasticity in determining peak displacement response under the notionally removed column.

  11. Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis.

    Science.gov (United States)

    Pflieger, Marilyne; Makorič, Petra; Kovač Viršek, Manca; Koren, Špela

    2017-07-01

    Plastic resin pellets, categorized as microplastics (≤5 mm in diameter), are small granules that can be unintentionally released to the environment during manufacturing and transport. Because of their environmental persistence, they are widely distributed in the oceans and on beaches all over the world. They can act as a vector of potentially toxic organic compounds (e.g., polychlorinated biphenyls) and might consequently negatively affect marine organisms. Their possible impacts along the food chain are not yet well understood. In order to assess the hazards associated with the occurrence of plastic pellets in the marine environment, it is necessary to develop methodologies that allow for rapid determination of associated organic contaminant levels. The present protocol describes the different steps required for sampling resin pellets, analyzing adsorbed organochlorine pesticides (OCPs) and identifying the plastic type. The focus is on the extraction of OCPs from plastic pellets by means of a pressurized fluid extractor (PFE) and on the polymer chemical analysis applying Fourier Transform-InfraRed (FT-IR) spectroscopy. The developed methodology focuses on 11 OCPs and related compounds, including dichlorodiphenyltrichloroethane (DDT) and its two main metabolites, lindane and two production isomers, as well as the two biologically active isomers of technical endosulfan. This protocol constitutes a simple and rapid alternative to existing methodology for evaluating the concentration of organic contaminants adsorbed on plastic pieces.

  12. Modeling and Analysis of Size-Dependent Structural Problems by Using Low- Order Finite Elements with Strain Gradient Plasticity

    International Nuclear Information System (INIS)

    Park, Moon Shik; Suh, Yeong Sung; Song, Seung

    2011-01-01

    An elasto-plastic finite element method using the theory of strain gradient plasticity is proposed to evaluate the size dependency of structural plasticity that occurs when the configuration size decreases to micron scale. For this method, we suggest a low-order plane and three-dimensional displacement-based elements, eliminating the need for a high order, many degrees of freedom, a mixed element, or super elements, which have been considered necessary in previous researches. The proposed method can be performed in the framework of nonlinear incremental analysis in which plastic strains are calculated and averaged at nodes. These strains are then interpolated and differentiated for gradient calculation. We adopted a strain-gradient-hardening constitutive equation from the Taylor dislocation model, which requires the plastic strain gradient. The developed finite elements are tested numerically on the basis of typical size-effect problems such as micro-bending, micro-torsion, and micro-voids. With respect to the strain gradient plasticity, i.e., the size effects, the results obtained by using the proposed method, which are simple in their calculation, are in good agreement with the experimental results cited in previously published papers

  13. 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

  14. Channel modelling and performance analysis of V2I communication systems in blind bend scattering environments

    KAUST Repository

    Chelli, Ali; Hamdi, Rami; Alouini, Mohamed-Slim

    2014-01-01

    In this paper, we derive a new geometrical blind bend scattering model for vehicle-to- infrastructure (V2I) communications. The proposed model takes into account single-bounce and double- bounce scattering stemming from fixed scatterers located

  15. User's guide to MITRE, a stress analysis program for Mitred pipe bends

    International Nuclear Information System (INIS)

    Beveridge, D.C.; Carmichael, G.D.T.

    1977-12-01

    The MITRE computer program calculates the flexibility factor, circumferential and longitudinal inside and outside surface bending stress ratio, pressure stresses, and total stresses around the mitre section at both the mid and edge section locations of a pressurised multimitred bend under in and/or out of plane bending. Additionally, the circumferential and longitudinal strains, equivalent stress (Mises and Tresca), principal stresses, and total stresses perpendicular and parallel to the edge section at the inside and outside surfaces are calculated for the edge section. The stresses sustained by single mitres subjected to internal pressure can also be evaluated for bends with either 'long' or 'short' leg lengths. Results are tabulated and plotted in graphical form on the line printer. (author)

  16. The Tower: Modelling, Analysis and Construction of Bending Active Tensile Membrane Hybrid Structures

    DEFF Research Database (Denmark)

    Holden Deleuran, Anders; Schmeck, Michel; Charles Quinn, Gregory

    2015-01-01

    The project is the result of an interdisciplinary research collaboration between CITA, KET and Fibrenamics exploring the design of integrated hybrid structures employing bending active elements and tensile membranes with bespoke material properties and detailing. Hybrid structures are defined her...

  17. Mass transfer coefficient factor in pipe bend - 3 D CFD analysis

    International Nuclear Information System (INIS)

    Prasad, Mahendra; Gaikwad, Avinash J.; Madasamy, P.; Krishnamohan, T.V.; Velumurugan, S.; Sridharan, Arunkumar; Parida, Smrutiranjan

    2015-01-01

    In power industries Flow Accelerated Corrosion (FAC) has been a concern for pipe wall thinning where high velocity fluid at elevated temperatures is used. Even straight pipes are found to have non uniform corrosion and this is enhanced in junctions such as bends, orifices etc. Mass transfer coefficient (MTC) which defines the amount of corrosion changes from its value in straight pipe (with same fluid parameters) for flow in bends, orifice etc due to changes in velocity profile in axial direction. In this paper, 3 D computational fluid dynamics (CFD) simulation is carried out for an experiment on 58° bend angle and 2D bend radius circular carbon steel pipe carrying water at 120°C under neutral pH conditions. The turbulent model K-ω with shear stress transport was used for this purpose. The mass transfer boundary layer (MTBL) thickness δ mtbl depends on Schmidt number (Sc), as δ mtbl ∼ δ h /(Sc 1/3 ). MTBL is significantly smaller than hydrodynamic boundary layer δ h for large Sc, hence boundary layer meshing was carried out deep into δ mtbl . Uniform velocity was applied at the inlet. The flow velocity was 3 m/s at room temperature while the experimental fluid velocity was 7 m/s. Lower value of fluid velocity is chosen due to the limitations of grid size since it depends inversely on fluid velocity. The ratio of MTC in bend to straight pipe is not strongly dependent on Sc. CFD simulation at lower temperature is sufficient to get approximate MTC in bends. The ratio of the mass transfer coefficient at some locations in bend to the straight pipe coefficient (MTCR) is determined through simulation. The MTC increased in the extrados of the bend towards the outlet. (author)

  18. Determination of inorganic component in plastics by neutron activation analysis

    International Nuclear Information System (INIS)

    Mateus, Sandra Fonseca; Saiki, Mitiko

    1995-01-01

    In order to identify possible sources of heavy metals in municipal solid waste incinerator ashes, plastic materials originated mainly from household waste were analyzed by using instrumental neutron activation analysis method. Plastic samples and synthetic standards of elements were irradiated at the IEA-R1 nuclear reactor for 8 h under thermal neutron flux of about 10 13 n cm -2 s -1 . After adequate decay time, counting were carried out using a hyperpure Ge detector and the concentrations of the elements As, Ba, Br, Cd, Co, Cr, Fe, Sb, Sc, Se, Sn, Ti and Zn were determined. For some samples, not all these elements were detected. Besides, the range of concentrations determined in similar type and colored samples varied from a few ppb to percentage. In general, colored and opaque plastic samples presented higher concentrations of the elements than those obtained from transparent and milky plastics. Precision of the results was also evaluated. (author). 3 refs., 2 tabs

  19. Springback Mechanism Analysis and Experiments on Robotic Bending of Rectangular Orthodontic Archwire

    Science.gov (United States)

    Jiang, Jin-Gang; Han, Ying-Shuai; Zhang, Yong-De; Liu, Yan-Jv; Wang, Zhao; Liu, Yi

    2017-11-01

    Fixed-appliance technology is the most common and effective malocclusion orthodontic treatment method, and its key step is the bending of orthodontic archwire. The springback of archwire did not consider the movement of the stress-strain-neutral layer. To solve this problem, a springback calculation model for rectangular orthodontic archwire is proposed. A bending springback experiment is conducted using an orthodontic archwire bending springback measurement device. The springback experimental results show that the theoretical calculation results using the proposed model coincide better with the experimental testing results than when movement of the stress-strain-neutral layer was not considered. A bending experiment with rectangular orthodontic archwire is conducted using a robotic orthodontic archwire bending system. The patient expriment result show that the maximum and minimum error ratios of formed orthodontic archwire parameters are 22.46% and 10.23% without considering springback and are decreased to 11.35% and 6.13% using the proposed model. The proposed springback calculation model, which considers the movement of the stress-strain-neutral layer, greatly improves the orthodontic archwire bending precision.

  20. Structural Analysis of Basalt Fiber Reinforced Plastic Wind Turbine Blade

    Directory of Open Access Journals (Sweden)

    Mengal Ali Nawaz

    2014-07-01

    Full Text Available In this study, Basalt fiber reinforced plastic (BFRP wind turbine blade was analyzed and compared with Glass fiber reinforced plastic blade (GFRP. Finite element analysis (FEA of blade was carried out using ANSYS. Data for FEA was obtained by using rule of mixture. The shell element in ANSYS was used to simulate the wind turbine blade and to conduct its strength analysis. The structural analysis and comparison of blade deformations proved that BFRP wind turbine blade has better strength compared to GFRP wind turbine blade.

  1. Proposal of failure criterion applicable to finite element analysis results for wall-thinned pipes under bending load

    Energy Technology Data Exchange (ETDEWEB)

    Meshii, Toshiyuki, E-mail: meshii@u-fukui.ac.jp [Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui (Japan); Ito, Yoshiaki [Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui (Japan)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Limit bending load (LBL) of wall-thinned pipe by large strain FEA was considered. Black-Right-Pointing-Pointer Net section yield load had sufficient margin to LBL. Black-Right-Pointing-Pointer LBL for collapse was the load when volume with nominal thickness yielded. Black-Right-Pointing-Pointer LBL for cracking was the load when flawed section stress exceeded tensile strength. Black-Right-Pointing-Pointer Failure criterion considering above was named Domain Collapse Criterion. - Abstract: In this work, a failure criterion applicable to large strain Finite Element Analysis (FEA) results was proposed in order to predict both the fracture mode (collapse or cracking) and the limit bending load of wall-thinned straight pipes. This work was motivated from the recent experimental results of ; that is, fracture mode is not always collapse, and the fracture mode affects the limit bending load. The key finding in comparing their test results and a detailed large strain FEA results was that the Mises stress distribution at the limit bending load of a flawed cylinder was similar to that of a flawless cylinder; specifically, in case of collapse, the Mises stress exceeded the true yield stress of a material for the whole 'volume' of a cylinder with a nominal wall thickness. Based on this finding, a failure criterion applicable to large strain FEA results of wall-thinned straight pipes under a bending load that can predict both fracture mode and limit bending load was proposed and was named the Domain Collapse Criterion (DCC). DCC predicts the limit bending load as the lower value of either the M{sub c}{sup FEA}, which is the load at which the Mises stress exceeds the true yield strength of a straight pipe for the whole 'volume' with a nominal wall thickness (fracture mode: collapse), or the M{sub c}{sup FEAb}, which is the load at which the Mises stress in a section of the flaw ligament exceeds the true tensile stress

  2. 3D MRI-based anisotropic FSI models with cyclic bending for human coronary atherosclerotic plaque mechanical analysis.

    Science.gov (United States)

    Tang, Dalin; Yang, Chun; Kobayashi, Shunichi; Zheng, Jie; Woodard, Pamela K; Teng, Zhongzhao; Billiar, Kristen; Bach, Richard; Ku, David N

    2009-06-01

    Heart attack and stroke are often caused by atherosclerotic plaque rupture, which happens without warning most of the time. Magnetic resonance imaging (MRI)-based atherosclerotic plaque models with fluid-structure interactions (FSIs) have been introduced to perform flow and stress/strain analysis and identify possible mechanical and morphological indices for accurate plaque vulnerability assessment. For coronary arteries, cyclic bending associated with heart motion and anisotropy of the vessel walls may have significant influence on flow and stress/strain distributions in the plaque. FSI models with cyclic bending and anisotropic vessel properties for coronary plaques are lacking in the current literature. In this paper, cyclic bending and anisotropic vessel properties were added to 3D FSI coronary plaque models so that the models would be more realistic for more accurate computational flow and stress/strain predictions. Six computational models using one ex vivo MRI human coronary plaque specimen data were constructed to assess the effects of cyclic bending, anisotropic vessel properties, pulsating pressure, plaque structure, and axial stretch on plaque stress/strain distributions. Our results indicate that cyclic bending and anisotropic properties may cause 50-800% increase in maximum principal stress (Stress-P1) values at selected locations. The stress increase varies with location and is higher when bending is coupled with axial stretch, nonsmooth plaque structure, and resonant pressure conditions (zero phase angle shift). Effects of cyclic bending on flow behaviors are more modest (9.8% decrease in maximum velocity, 2.5% decrease in flow rate, 15% increase in maximum flow shear stress). Inclusion of cyclic bending, anisotropic vessel material properties, accurate plaque structure, and axial stretch in computational FSI models should lead to a considerable improvement of accuracy of computational stress/strain predictions for coronary plaque vulnerability

  3. Burgers vector analysis of large area misfit dislocation arrays from bend contour contrast in transmission electron microscope images

    CERN Document Server

    Spiecker, E

    2002-01-01

    A transmission electron microscopy method is described which allows us to determine the Burgers vectors (BVs) of a large number of interfacial misfit dislocations (MDs) in mismatched heterostructures. The method combines large-area plan-view thinning of the sample for creating a strongly bent electron transparent foil with the analysis of the splitting and displacement of bend contours at their crossings with the MDs. The BV analysis is demonstrated for 60 deg. MDs in a low-mismatched SiGe/Si(001) heterostructure. Crossings of various bend contours with the MDs are analysed with respect to their information content for the BV analysis. In future applications the method may be used for analysing such a large number of MDs that a quantitative comparison with x-ray diffraction experiments, especially with data on diffusely scattered x-rays originating from the strain fields around the dislocations, becomes possible.

  4. Analysis and Comparison of Thickness and Bending Measurements from Fabric Touch Tester (FTT and Standard Methods

    Directory of Open Access Journals (Sweden)

    Musa Atiyyah Binti Haji

    2018-03-01

    Full Text Available Fabric Touch Tester (FTT is a relatively new device from SDL Atlas to determine touch properties of fabrics. It simultaneously measures 13 touch-related fabric physical properties in four modules that include bending and thickness measurements. This study aims to comparatively analyze the thickness and bending measurements made by the FTT and the common standard methods used in the textile industry. The results obtained with the FTT for 11 different fabrics were compared with that of standard methods. Despite the different measurement principle, a good correlation was found between the two methods used for the assessment of thickness and bending. As FTT is a new tool for textile comfort measurement and no standard yet exists, these findings are essential to determine the reliability of the measurements and how they relate to the well-established standard methods.

  5. Determination of elastic-plastic properties of Alporas foam at the cell-wall level using microscale-cantilever bending tests

    Czech Academy of Sciences Publication Activity Database

    Doktor, Tomáš; Kytýř, Daniel; Koudelka_ml., Petr; Zlámal, Petr; Fíla, Tomáš; Jiroušek, Ondřej

    2015-01-01

    Roč. 49, č. 2 (2015), s. 203-206 ISSN 1580-2949 R&D Projects: GA ČR(CZ) GAP105/12/0824 Institutional support: RVO:68378297 Keywords : aluminium foam * cantilever bending * micromechanics * optical strain measurement Subject RIV: JI - Composite Materials Impact factor: 0.439, year: 2015 http://mit.imt.si/Revija/izvodi/mit152/doktor.pdf

  6. Reliability improvement of a-Si:H thin film transistors on plastic substrate with saturation in deep state after multiple bending cycles

    International Nuclear Information System (INIS)

    Lee, M.H.; Chen, P.-G.; Hsu, C.-C.

    2013-01-01

    For flexible electronic applications, the disordered bonds of a-Si:H may generate a redistribution of trapped states with mechanical strain. During mechanical strain, the deep states are redistributed in a Gaussian distribution and are dissimilar to ordinary acceptor-like deep states, which manifest with exponential distributions. The redistributed deep states may saturate with multiple mechanical bending cycles, and it would improve the reliability with drain current stress of a-Si:H TFTs (thin film transistors) on flexible substrates. We conclude that it is possible to produce low-cost and highly uniform active-matrix organic light emitting diodes systems for use in flexible display applications using a-Si:H TFTs array backplanes. - Highlights: • The stress stability of a-Si:H TFTs (thin-film transistors) was improved after bending cycles. • The saturated deep states after bending were confirmed. • The simulation and extracted gap state density of a-Si:H TFT under strain was calculated

  7. Evaluating source separation of plastic waste using conjoint analysis.

    Science.gov (United States)

    Nakatani, Jun; Aramaki, Toshiya; Hanaki, Keisuke

    2008-11-01

    Using conjoint analysis, we estimated the willingness to pay (WTP) of households for source separation of plastic waste and the improvement of related environmental impacts, the residents' loss of life expectancy (LLE), the landfill capacity, and the CO2 emissions. Unreliable respondents were identified and removed from the sample based on their answers to follow-up questions. It was found that the utility associated with reducing LLE and with the landfill capacity were both well expressed by logarithmic functions, but that residents were indifferent to the level of CO2 emissions even though they approved of CO2 reduction. In addition, residents derived utility from the act of separating plastic waste, irrespective of its environmental impacts; that is, they were willing to practice the separation of plastic waste at home in anticipation of its "invisible effects", such as the improvement of citizens' attitudes toward solid waste issues.

  8. In-plane and out-of-plane bending tests on carbon steel pipe bends

    International Nuclear Information System (INIS)

    Brouard, D.; Tremblais, A.; Vrillon, B.

    1979-01-01

    The objectives of these tests were to obtain experimental results on bends behaviour in elastic and plastic regime by in plane and out of plane bending. Results were used to improve the computer model, for large distorsion of bends, to be used in a simplified beam type computer code for piping calculations. Tests were made on type ANSI B 169 DN 5 bends in ASTM A 106 Grade B carbon steel. These tests made it possible to measure, for identical bends, in elastic regime, the flexibility factors and, in plastic regime, the total evolution in opening, in closing and out of plane. Flexibility factors of 180 0 bend without flanges are approximately the same in opening and in closing. The end effect due to flanges is not very significant, but it is important for 90 0 bends. In plastic regime, collapse loads or collapse moments of bends depends also of both the end effects and the angle bend. The end effects and the angle bend are more sensitive in opening than in closing. The interest of these tests is to procure some precise evolution curves of identical bends well characterized in geometry and metal strength, deflected in large distorsions. (orig./HP)

  9. Elastic Plastic Fracture Analysis of an Aluminum COPV Liner

    Science.gov (United States)

    Forth, Scott; Gregg, Bradley; Bailey, Nathaniel

    2012-01-01

    Onboard any space-launch vehicle, composite over-wrapped pressure vessels (COPVs) may be utilized by propulsion or environmental control systems. The failure of a COPV has the potential to be catastrophic, resulting in the loss of vehicle, crew or mission. The latest COPV designs have reduced the wall-thickness of the metallic liner to the point where the material strains plastically during operation. At this time, the only method to determine the damage tolerance lifetime (safe-life) of a plastically responding metallic liner is through full-scale COPV testing. Conducting tests costs substantially more and can be far more time consuming than performing an analysis. As a result of this cost, there is a need to establish a qualifying process through the use of a crack growth analysis tool. This paper will discuss fracture analyses of plastically responding metallic liners in COPVs. Uni-axial strain tests have been completed on laboratory specimens to collect elastic-plastic crack growth data. This data has been modeled with the crack growth analysis tool, NASGRO 6.20 to predict the response of laboratory specimens and subsequently the complexity of a COPV.

  10. Reliability Analysis of Elasto-Plastic Structures

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Sørensen, John Dalsgaard

    1984-01-01

    . Failure of this type of system is defined either as formation of a mechanism or by failure of a prescribed number of elements. In the first case failure is independent of the order in which the elements fail, but this is not so by the second definition. The reliability analysis consists of two parts...... are described and the two definitions of failure can be used by the first formulation, but only the failure definition based on formation of a mechanism by the second formulation. The second part of the reliability analysis is an estimate of the failure probability for the structure on the basis...

  11. Bend testing for miniature disks

    International Nuclear Information System (INIS)

    Huang, F.H.; Hamilton, M.L.; Wire, G.L.

    1982-01-01

    A bend test was developed to obtain ductility measurements on a large number of alloy variants being irradiated in the form of miniature disks. Experimental results were shown to be in agreement with a theoretical analysis of the bend configuration. Disk specimens fabricated from the unstrained grip ends of previously tested tensile specimens were used for calibration purposes; bend ductilities and tensile ductilities were in good agreement. The criterion for estimating ductility was judged acceptable for screening purposes

  12. A Temperature Sensor Based on a Polymer Optical Fiber Macro-Bend

    Directory of Open Access Journals (Sweden)

    Joseba Zubia Zaballa

    2013-09-01

    Full Text Available The design and development of a plastic optical fiber (POF macrobend temperature sensor is presented. The sensor has a linear response versus temperature at a fixed bend radius, with a sensitivity of . The sensor system used a dummy fiber-optic sensor for reference purposes having a resolution below 0.3 °C. A comprehensive experimental analysis was carried out to provide insight into the effect of different surrounding media on practical macro-bend POF sensor implementation. Experimental results are successfully compared with bend loss calculations.

  13. A Temperature Sensor Based on a Polymer Optical Fiber Macro-Bend

    Science.gov (United States)

    Moraleda, Alberto Tapetado; García, Carmen Vázquez; Zaballa, Joseba Zubia; Arrue, Jon

    2013-01-01

    The design and development of a plastic optical fiber (POF) macrobend temperature sensor is presented. The sensor has a linear response versus temperature at a fixed bend radius, with a sensitivity of 1.92·10−3 (°C)−1. The sensor system used a dummy fiber-optic sensor for reference purposes having a resolution below 0.3 °C. A comprehensive experimental analysis was carried out to provide insight into the effect of different surrounding media on practical macro-bend POF sensor implementation. Experimental results are successfully compared with bend loss calculations. PMID:24077323

  14. A comparative study on free vibration analysis of delaminated torsion stiff and bending stiff composite shells

    International Nuclear Information System (INIS)

    Dey, Sudip; Karmakar, Amit

    2013-01-01

    This paper presents a finite element method to compare the effects of delamination on free vibration of graphite-epoxy bending stiff and torsion stiff composite pretwisted shallow conical shells. The generalized dynamic equilibrium equation is derived from Lagrange's equation of motion neglecting the Coriolis effect for moderate rotational speeds. An eight noded isoparametric plate bending element is employed incorporating rotary inertia and effects of transverse shear deformation based on Mindlin's theory. The multipoint constraint; algorithm is utilized to ensure the compatibility of deformation and equilibrium of resultant forces and moments at the delamination crack front. The standard eigen value problem is solved by applying the QR iteration algorithm. Mode shapes for typical configurations are also depicted. Numerical results obtained are the first known non-dimensional frequencies which could serve as reference solutions for the future investigators.

  15. Experimental and theoretical analysis of integrated circuit (IC) chips on flexible substrates subjected to bending

    Science.gov (United States)

    Chen, Ying; Yuan, Jianghong; Zhang, Yingchao; Huang, Yonggang; Feng, Xue

    2017-10-01

    The interfacial failure of integrated circuit (IC) chips integrated on flexible substrates under bending deformation has been studied theoretically and experimentally. A compressive buckling test is used to impose the bending deformation onto the interface between the IC chip and the flexible substrate quantitatively, after which the failed interface is investigated using scanning electron microscopy. A theoretical model is established based on the beam theory and a bi-layer interface model, from which an analytical expression of the critical curvature in relation to the interfacial failure is obtained. The relationships between the critical curvature, the material, and the geometric parameters of the device are discussed in detail, providing guidance for future optimization flexible circuits based on IC chips.

  16. Failure analysis of fusion clad alloy system AA3003/AA6xxx sheet under bending

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Y., E-mail: shiyh@mcmaster.ca [Department of Mechanical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada); Jin, H. [Novelis Global Technology Center, P.O. Box 8400, Kingston, Ontario, Canada K7L 5L9 (Canada); Wu, P.D. [Department of Mechanical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada); Lloyd, D.J. [Aluminum Materials Consultants, 106 Nicholsons Point Road, Bath, Ontario, Canada K0H 1G0 (Canada); Embury, D. [Department of Mechanical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada)

    2014-07-29

    An ingot of AA6xxx Al–Si–Mg–Cu alloy clad with AA3003 Al–Mn alloy was co-cast by Fusion technology. Bending tests and numerical modeling were performed to investigate the potential for sub-surface cracking for this laminate system. To simulate particle-induced crack initiation and growth, both random and stringer particles have been selected to mimic the particle distribution in the tested samples. The morphology of cracking in the model was similar to that observed in clad sheet tested in the Cantilever bend test. The crack initiated in the core close to the clad-core interface where the strain in the core is highest, between particles or near particles and propagates along local shear bands in the core, while the clad layer experiences extreme thinning before failure.

  17. Weibull statistic analysis of bending strength in the cemented carbide coatings

    International Nuclear Information System (INIS)

    Yi Yong; Shen Baoluo; Qiu Shaoyu; Li Cong

    2003-01-01

    The theoretical basis using Weibull statistics to analyze the strength of coating has been established that the Weibull distribution will be the asymptotic distribution of strength for coating as the volume of coating increase, provided that the local strength of coating is statistic independent, and has been confirmed in the following test for the bending strength of two cemented carbide coatings. The result shows that Weibull statistics can be well used to analyze the strength of two coatings. (authors)

  18. Dynamic statistical optimization of GNSS radio occultation bending angles: advanced algorithm and performance analysis

    Science.gov (United States)

    Li, Y.; Kirchengast, G.; Scherllin-Pirscher, B.; Norman, R.; Yuan, Y. B.; Fritzer, J.; Schwaerz, M.; Zhang, K.

    2015-08-01

    We introduce a new dynamic statistical optimization algorithm to initialize ionosphere-corrected bending angles of Global Navigation Satellite System (GNSS)-based radio occultation (RO) measurements. The new algorithm estimates background and observation error covariance matrices with geographically varying uncertainty profiles and realistic global-mean correlation matrices. The error covariance matrices estimated by the new approach are more accurate and realistic than in simplified existing approaches and can therefore be used in statistical optimization to provide optimal bending angle profiles for high-altitude initialization of the subsequent Abel transform retrieval of refractivity. The new algorithm is evaluated against the existing Wegener Center Occultation Processing System version 5.6 (OPSv5.6) algorithm, using simulated data on two test days from January and July 2008 and real observed CHAllenging Minisatellite Payload (CHAMP) and Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) measurements from the complete months of January and July 2008. The following is achieved for the new method's performance compared to OPSv5.6: (1) significant reduction of random errors (standard deviations) of optimized bending angles down to about half of their size or more; (2) reduction of the systematic differences in optimized bending angles for simulated MetOp data; (3) improved retrieval of refractivity and temperature profiles; and (4) realistically estimated global-mean correlation matrices and realistic uncertainty fields for the background and observations. Overall the results indicate high suitability for employing the new dynamic approach in the processing of long-term RO data into a reference climate record, leading to well-characterized and high-quality atmospheric profiles over the entire stratosphere.

  19. Fracture mechanics analysis of a longitudinally cracked bend under cyclic loading

    International Nuclear Information System (INIS)

    Kussmaul, K.; Uhlmann, D.; Koski, K.; Hunger, H.

    1993-01-01

    Where information is available about the actual crack configuration, the boundary conditions of the load case, the geometry, and the material characteristics, extensive numerical calculations by means of the finite element method allow crack growth to be calculated for pipe bends carrying longitudinal cracks. If the influence of multiple-crack fields is taken into account in the crack growth calculations, good agreement is obtained with experimental findings. Less sophisticated assessments of individual cracks furnish results which are on the safe side. (author)

  20. Vibration Analysis of Cracked Composite Bending-torsion Beams for Damage Diagnosis

    OpenAIRE

    Wang, Kaihong

    2004-01-01

    An analytical model of cracked composite beams vibrating in coupled bending-torsion is developed. The beam is made of fiber-reinforced composite with fiber angles in each ply aligned in the same direction. The crack is assumed open. The local flexibility concept is implemented to model the open crack and the associated compliance matrix is derived. The crack introduces additional boundary conditions at the crack location and these effects in conjunction with those of material properties are i...

  1. Analysis of ductile-brittle transition shifts for standard and miniature bending specimens of irradiated steel

    International Nuclear Information System (INIS)

    Korshunov, M.E.; Korolev, Yu.N.; Krasikov, E.A.; Gabuev, N.N.; Tykhmeev, D.Yu.

    1996-01-01

    A study is made to reveal if there is a correlation between shifts in temperature curves obtained when testing thin plates and standard specimens on impact bending and fracture toughness. The tests were carried out using steel 25Kh3NM specimens irradiated by 6 x 10 19 cm -2 neutron fluence. A conclusion is made about the possibility to evaluate the degree of radiation-induced embrittlement of reactor steels on the basis of thin plate testing under quasistatic loads [ru

  2. Inelastic analysis of piping systems. A beam-type method for creep and plasticity

    International Nuclear Information System (INIS)

    Roche, R.L.; Hoffmann, A.; Millard, A.

    1979-01-01

    Since many years, piping systems are designed and calculated under elasticity assumptions, using a beam-type method. Thus, the analysis of large systems may be performed at a relatively low cost, using a finite element program. However such a method can not account for inelastic phenomena like plastic deformations or creep. The application of refined three-dimensional shell type method is possible for local components such as curved sections but leads to prohibitive costs for complete piping systems. Therefore simplified methods have been developed, based on a 'global plasticity or creep model'. Following the conventional elastic approach, the pipe element is characterized by variables associated with the center line in the following way: generalized stresses are obtained by integration of local stresses giving way to hoop and tension stresses and to bending and torsional moments; the conjugated strains are identified with uniform hoop and longitudinal strains and variations in neutral axis curvatuves. For plasticity problems, the yield surface is defined by a diagonal quadratic function in terms of the generalized stresses and work hardening parameters. By addition of the Hill's principle and a hardening rule, the formulation is similar to the one commonly used in finite element method. Geometric non linearity due to important deformations of the cross section (often termed 'ovalization') may be treated simultaneously with material non linearity. For this purpose the displacement normal to the pipe surface is represented by trigonometric series expansion, the coefficients of which are determined by minimizing the strain energy over the cross section. The method presented is believed to be a simple economical and accurate tool, for dimensioning computations of large piping systems

  3. An analysis of the temperature distribution in the pipe bending using high frequency induction heating

    International Nuclear Information System (INIS)

    Fukue, Hisayoshi; Mochizuki, Yoji; Nakamura, Harushige; Kobo, Hiroshi; Nitta, Tetsuo; Kawakami, Kiyoshi

    1986-01-01

    A pipe bending apparatus has recently been developed by applying high frequency induction heating. However, the smaller the radius of pipe bending, the greater becomes the reduction in wall thickness and the ovality of the pipe form. This makes it impossible to manufacture pipe bending which will meet the nuclear pipe design code. In order to solve this problem it is crucial to obtain a temperature distributions in a pipe which is moving. It is calculated by giving the following boundary conditions : distribution of the heat generation rate, and that of heat transfer of cooling water. In the process of analyzing these distributions, the following results were obtained. (1) The distribution of the heat generation rate is determined by the sink of energy flux of Poynting vectors. The coil efficiency thus calculated was sixty percent. This figure accords with the test data. (2) The distribution of heat transfer coefficient of cooling water is mainly determined by the rate of liquid film heat transfer, but departure from nucleate boiling and dryout has to be taken into consideration. (3) TRUMP CODE is modified so that the temperature distribution in moving pipes can be calculated by taking the boundary conditions into account. The calculated results were in accordance with the test data. (author)

  4. Application of perturbation theory to the non-linear vibration analysis of a string including the bending moment effects

    International Nuclear Information System (INIS)

    Esmaeilzadeh Khadem, S.; Rezaee, M.

    2001-01-01

    In this paper the large amplitude and non-linear vibration of a string is considered. The initial tension, lateral vibration amplitude, diameter and the modulus of elasticity of the string have main effects on its natural frequencies. Increasing the lateral vibration amplitude makes the assumption of constant initial tension invalid. In this case, therefore, it is impossible to use the classical equation of string with small amplitude transverse motion assumption. On the other hand, by increasing the string diameter, the bending moment effect will increase dramatically, and acts as an impressive restoring moment. Considering the effects of the bending moments, the nonlinear equation governing the large amplitude transverse vibration of a string is derived. The time dependent portion of the governing equation has the from of Duff ing equation is solved using the perturbation theory. The results of the analysis are shown in appropriate graphs, and the natural frequencies of the string due to the non-linear factors are compared with the natural frequencies of the linear vibration os a string without bending moment effects

  5. Analysis of lumbar spine and hip motion during forward bending in subjects with and without a history of low back pain.

    Science.gov (United States)

    Esola, M A; McClure, P W; Fitzgerald, G K; Siegler, S

    1996-01-01

    This study analyzed two groups of subjects during forward bending. Group 1 (n = 20) contained subjects with a history of low back pain and Group 2 (n = 21) included subjects without a history of low back pain. The purposes of this study were to establish the amount and pattern of lumbar spine and hip motion during forward bending, and determine differences in motion in subjects with and without a history of low back pain. Reported values for lumbar spine motion during forward bending vary from 23.9 degrees to 60 degrees and hip motion during forward bending ranges from 26 degrees to 66 degrees. There has been no direct study of both lumbar spine and hip motion during forward bending in subjects with and without a history of low back pain to establish differences in total amounts or pattern of lumbar spine and hip motion during forward bending. A three-dimensional optoelectric motion analysis system was used to measure the amount and velocity of lumbar spine and hip motion during forward bending. Each subject performed three trials of forward bending that were averaged and used for statistical analysis. Hamstring flexibility was also assessed by two clinical tests, the passive straight leg raising and active knee extension tests. Mean total forward bending for all subjects was 111 degrees: 41.6 degrees from the lumbar spine and 69.4 degrees from the hips. There were no group differences for total amounts of lumbar spine and hip motion or velocity during forward bending. The pattern of motion was described by calculating lumbar-to-hip flexion ratios for early (0-30 degrees), middle (30-60 degrees), and late (60-90 degrees) forward bending. For all subjects, mean lumbar-to-hip ratios for early, middle, and late forward bending were 1.9, 0.9, and 0.4, respectively. Therefore, the lumbar spine had a greater contribution to early forward bending, the lumbar spine and hips contributed almost equally to middle forward bending, and the hips had a greater contribution to

  6. Using Statistical Analysis Software to Advance Nitro Plasticizer Wettability

    Energy Technology Data Exchange (ETDEWEB)

    Shear, Trevor Allan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-29

    Statistical analysis in science is an extremely powerful tool that is often underutilized. Additionally, it is frequently the case that data is misinterpreted or not used to its fullest extent. Utilizing the advanced software JMP®, many aspects of experimental design and data analysis can be evaluated and improved. This overview will detail the features of JMP® and how they were used to advance a project, resulting in time and cost savings, as well as the collection of scientifically sound data. The project analyzed in this report addresses the inability of a nitro plasticizer to coat a gold coated quartz crystal sensor used in a quartz crystal microbalance. Through the use of the JMP® software, the wettability of the nitro plasticizer was increased by over 200% using an atmospheric plasma pen, ensuring good sample preparation and reliable results.

  7. Automated analysis of damages for radiation in plastics surfaces

    International Nuclear Information System (INIS)

    Andrade, C.; Camacho M, E.; Tavera, L.; Balcazar, M.

    1990-02-01

    Analysis of damages done by the radiation in a polymer characterized by optic properties of polished surfaces, of uniformity and chemical resistance that the acrylic; resistant until the 150 centigrade grades of temperature, and with an approximate weight of half of the glass. An objective of this work is the development of a method that analyze in automated form the superficial damages induced by radiation in plastic materials means an images analyst. (Author)

  8. Finite Element Analysis of High Heat Load Deformation and Mechanical Bending Correction of a Beamline Mirror for the APS Upgrade

    Science.gov (United States)

    Goldring, Nicholas

    The impending Advanced Photon Source Upgrade (APS-U) will introduce a hard x-ray source that is set to surpass the current APS in brightness and coherence by two to three orders of magnitude. To achieve this, the storage ring light source will be equipped with a multi-bend achromat (MBA) lattice. In order to fully exploit and preserve the integrity of new beams actualized by upgraded storage ring components, improved beamline optics must also be introduced. The design process of new optics for the APS-U and other fourth generation synchrotrons involves the challenge of accommodating unprecedented heat loads. This dissertation presents an ex-situ analysis of heat load deformation and the subsequent mechanical bending correction of a 400 mm long, grazing-incidence, H2O side-cooled, reflecting mirror subjected to x-ray beams produced by the APS-U undulator source. Bending correction is measured as the smallest rms slope error, sigmarms, that can be resolved over a given length of the heat deformed geometry due to mechanical bending. Values of sigmarms in the account for finish errors or other contributions to sigmarms beyond the scope of thermal deformation and elastic bending. The methodology of this research includes finite element analysis (FEA) employed conjointly with an analytical solution for mechanical bending deflection by means of an end couple. Additionally, the study will focus on two beam power density profiles predicted by the APS-U which were created using the software SRCalc. The profiles account for a 6 GeV electron beam with second moment widths of 0.058 and 0.011 mm in the x- and y- directions respectively; the electron beam is passed through a 4.8 m long, 28 mm period APS-U undulator which produces the x-ray beam incident at a 3 mrad grazing angle on the flat mirror surface for both cases. The first power density profile is the most extreme case created by the undulator at it's closest gap with a critical energy of 3 keV (k y=2.459); the second

  9. Investigation on method of elasto-plastic analysis for piping system (benchmark analysis)

    International Nuclear Information System (INIS)

    Kabaya, Takuro; Kojima, Nobuyuki; Arai, Masashi

    2015-01-01

    This paper provides method of an elasto-plastic analysis for practical seismic design of nuclear piping system. JSME started up the task to establish method of an elasto-plastic analysis for nuclear piping system. The benchmark analyses have been performed in the task to investigate on method of an elasto-plastic analysis. And our company has participated in the benchmark analyses. As a result, we have settled on the method which simulates the result of piping exciting test accurately. Therefore the recommended method of an elasto-plastic analysis is shown as follows; 1) An elasto-plastic analysis is composed of dynamic analysis of piping system modeled by using beam elements and static analysis of deformed elbow modeled by using shell elements. 2) Bi-linear is applied as an elasto-plastic property. Yield point is standardized yield point multiplied by 1.2 times, and second gradient is 1/100 young's modulus. Kinematic hardening is used as a hardening rule. 3) The fatigue life is evaluated on strain ranges obtained by elasto-plastic analysis, by using the rain flow method and the fatigue curve of previous studies. (author)

  10. Analysis of the Mechanism of Longitudinal Bending Deformation Due to Welding in a Steel Plate by Using a Numerical Model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Rae; Yan, Jieshen; Kim, Jae-Woong [Yeungnam Univ., Gyeongsan (Korea, Republic of); Song, Gyu Yeong [Gyeongbuk Hybrid Technology Institute, Yeongcheon (Korea, Republic of)

    2017-01-15

    Welding deformation is a permanent deformation that is caused in structures by welding heat. Welding distortion is the primary cause of reduced productivity, due to welded structural strength degradation, low dimensional accuracy, and appearance. As a result, research and numerous experiments are being carried out to control welding deformation. The aim of this study is to analyze the mechanism of longitudinal bending deformation due to welding. Welding experiments and numerical analyses were performed for this study. The welding experiments were performed on 4 mm and 8.5 mm thickness steel plates, and the numerical analysis was conducted on the welding deformation using the FE software MSC.marc.

  11. Channel modelling and performance analysis of V2I communication systems in blind bend scattering environments

    KAUST Repository

    Chelli, Ali

    2014-01-01

    In this paper, we derive a new geometrical blind bend scattering model for vehicle-to- infrastructure (V2I) communications. The proposed model takes into account single-bounce and double- bounce scattering stemming from fixed scatterers located on both sides of a curved street. Starting from the geometrical blind bend model, the exact expression of the angle of departure (AOD) is derived. Based on this expression, the probability density function (PDF) of the AOD and the Doppler power spectrum are determined. Analytical expressions for the channel gain and the temporal autocorrelation function (ACF) are provided under non-line-of-sight (NLOS) conditions. Additionally, we investigate the impact of the position of transmitting vehicle relatively to the receiving road-side unit on the channel statistics. Moreover, we study the performance of different digital modulations over a sum of singly and doubly scattered (SSDS) channel. Note that the proposed V2I channel model falls under the umbrella of SSDS channels since the transmitted signal undergoes a combination of single-bounce and double-bounce scattering. We study some characteristic quantities of SSDS channels and derive expressions for the average symbol error probability of several modulation schemes over SSDS channels with and without diversity combining. The validity of these analytical expressions is confirmed by computer-based simulations.

  12. Transient analysis of air-water two-phase flow in channels and bends

    International Nuclear Information System (INIS)

    Khan, H.J.; Ye, W.; Pertmer, G.A.

    1992-01-01

    The algorithm used in this paper is the Newton Block Gauss Seidel method, which has been applied to both simple and complex flow conditions in two-phase flow. This paper contains a description of difference techniques and an iterative solution algorithm that is used to solve the field and constitutive equations of the two-fluid model. In practice, this solution procedure has been proven to be stable and capable of generating solutions in problems where other schemes have failed. The method converges rapidly for reasonable error tolerances and is easily extended to three-dimensional geometries. Using air-water as the two-phase medium, transient flow behavior in several geometries of interest are shown. Flow through a vertical channel with flow obstruction, large U bends, and 90-deg bends are being demonstrated with variation of inlet void fraction and slip ratio. Significant changes in the velocity and void distribution profiles have been observed. Various regions of flow recirculation are obtained in the flow domain for each phase. The phasic velocity and void distributions are dominated by gravity-induced phase separation causing air to accumulate in the upper region. The influence of inlet slip ratio and interfacial momentum transfer on the transient flow profile has been demonstrated in detail

  13. Experimental and Numerical Analysis of Damage in Woven GFRP Composites Under Large-deflection Bending

    Science.gov (United States)

    Ullah, Himayat; Harland, Andy R.; Silberschmidt, Vadim V.

    2012-10-01

    Textile-reinforced composites such as glass fibre-reinforced polymer (GFRP) used in sports products can be exposed to different in-service conditions such as large bending deformation and multiple impacts. Such loading conditions cause high local stresses and strains, which result in multiple modes of damage and fracture in composite laminates due to their inherent heterogeneity and non-trivial microstructure. In this paper, various damage modes in GFRP laminates are studied using experimental material characterisation, non-destructive micro-structural damage evaluation and numerical simulations. Experimental tests are carried out to characterise the behaviour of these materials under large-deflection bending. To obtain in-plane shear properties of laminates, tensile tests are performed using a full-field strain-measurement digital image correlation technique. X-ray micro computed tomography (Micro CT) is used to investigate internal material damage modes - delamination and cracking. Two-dimensional finite element (FE) models are implemented in the commercial code Abaqus to study the deformation behaviour and damage in GFRP. In these models, multiple layers of bilinear cohesive-zone elements are employed to study the onset and progression of inter-ply delamination and intra-ply fabric fracture of composite laminate, based on the X-ray Micro CT study. The developed numerical models are capable to simulate these features with their mechanisms as well as subsequent mode coupling observed in tests and Micro CT scanning. The obtained results of simulations are in agreement with experimental data.

  14. The Faraday Pavilion: activating bending in the design and analysis of an elastic gridshell

    DEFF Research Database (Denmark)

    Nicholas, Paul; Lafuente Hernandez, Elisa; Gengnagel, Christoph

    2013-01-01

    This paper reports the architectural and engineering design, and construction, of The Faraday Pavilion, a GFRP elastic gridshell with an irregular grid topology. Gridshell structures are self-formed through an erection process in which they are elastically deformed, and the prediction and steerin......, which while complementary have important differences relating to the interaction with the design of the structure, differences in the definition of supports, connections and elements, the speed of calculation and the magnitude and precision of the results....... and light-weight design approach to bending active structures is not currently developed. In this paper, we introduce an approach to the architectural design of a bending active structure whereby the shell form and grid topology are determined by simulation. Particular features are that the grid topology...... is not pre-described, but rather emerges as part of the simulation, and that different calculative models relating to the material, element and structural scales are solved and synthesized by extending the technique of dynamic relaxation. Secondly, the results of this design modelling are provided...

  15. Lab-scale thermal analysis of electronic waste plastics

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wu-Jun; Tian, Ke; Jiang, Hong, E-mail: jhong@ustc.edu.cn; Yu, Han-Qing

    2016-06-05

    Highlights: • We provided the experimental evidence that WEEE can be recovered by pyrolysis method. • We explored the thermochemical behaviors of WEEE using online TG–FTIR–MS technology. • The intramolecular oxygen atoms play a pivotal role in the formation of PBDD/Fs. - Abstract: In this work, we experimentally revealed the thermochemical decomposition pathway of Decabromodiphenyl ethane (DBDPE) and tetrabromobisphenol A (TBBPA) containing electronic waste plastics using an online thermogravimetric–fourier transform infrared–mass spectroscopy (TG–FTIR–MS) system, a high resolution gas chromatography/high resolution mass (HRGC–MS) spectroscopy, and a fixed-bed reactor. We found the distribution and species of produced bromides can be easily controlled by adjusting pyrolytic temperature, which is particularly crucial to their recycle. From the analysis of the liquid and solid phase obtained from the fixed-bed reactor, we proposed that the ·Br radicals formed during the pyrolysis process may be captured by organic species derived from the depolymerization of plastics to form brominated compounds or by the inorganic species in the plastics, and that these species remained in the char residue after pyrolysis. Our work for the first time demonstrates intramolecular oxygen atoms play a pivotal role in the formation of PBDD/Fs that pyrolysis of oxygen-free BFRs is PBDD/Fs-free, whereas pyrolysis of oxygen-containing BFRs is PBDD/Fs-reduced.

  16. Limit load and fully plastic stress analysis for circular notched plates and bars using fully plastic analysis

    International Nuclear Information System (INIS)

    Oh, Chang Kyun; Myung, Man Sik; Kim, Yun Jae; Park, Jin Moo

    2005-01-01

    For the last four decades, tension test of notched bars has been performed to investigate the effect of stress triaxiality on ductile fracture. To quantify the effect of the notch radius on stress triaxiality, the Bridgman equation is typically used. However, recent works based on detailed finite element analysis have shown that the Bridgman equation is not correct, possibly due to his assumption that strain is constant in the necked ligament. Up to present, no systematic work has been performed on fully plastic stress fields for notched bars in tension. This paper presents fully plastic results for tension of notched bars and plates in plane strain, via finite element limit analysis. The notch radius is systematically varied, covering both un-cracked and cracked cases. Comparison of plastic limit loads with existing solutions shows that existing solutions are accurate for notched plates, but not for notched bars. Accordingly new limit load solutions are given for notched bars. Variations of stress triaxiality with the notch radius and depth are also given, which again indicates that the Bridgman solution for notched bars is not correct and inaccuracy depends on the notch radius and depth

  17. Effect of Ovality in Inlet Pigtail Pipe Bends Under Combined Internal Pressure and In-Plane Bending for Ni-Fe-Cr B407 Material

    Directory of Open Access Journals (Sweden)

    Ramaswami P.

    2017-09-01

    Full Text Available The present paper makes an attempt to depict the effect of ovality in the inlet pigtail pipe bend of a reformer under combined internal pressure and in-plane bending. Finite element analysis (FEA and experiments have been used. An incoloy Ni-Fe-Cr B407 alloy material was considered for study and assumed to be elastic-perfectly plastic in behavior. The design of pipe bend is based on ASME B31.3 standard and during manufacturing process, it is challenging to avoid thickening on the inner radius and thinning on the outer radius of pipe bend. This geometrical shape imperfection is known as ovality and its effect needs investigation which is considered for the study. The finite element analysis (ANSYS-workbench results showed that ovality affects the load carrying capacity of the pipe bend and it was varying with bend factor (h. By data fitting of finite element results, an empirical formula for the limit load of inlet pigtail pipe bend with ovality has been proposed, which is validated by experiments.

  18. The study of elastio-plastic seismic analysis for rigid-frame structures

    OpenAIRE

    陳, 珉; 青木, 徹彦

    2000-01-01

    Elastic and elastio-plastic earthquake-resistant analysis of frame construction is mainly studied in this paper. In elastic stage, response and vibrated characteristics of symmetrical and unsymmetrical structure are investigated by comparing the results of plane and space analysis. The effect of approaching angle of seismic wave to vibrated characteristics of structure under different column/beam rate are discussed. In elastio-plastic stage, four kinds of plastic mode with different plastic p...

  19. Analysis of the bending radius of the cylindrical waveguide of polydimethylsiloxane for the purpose of lighting

    Science.gov (United States)

    Novak, M.; Jargus, J.; Fajkus, M.; Bednarek, L.; Vasinek, V.

    2017-10-01

    Polydimethylsiloxane (PDMS) can be used for its optical properties and its composition offers the possibility of use in the dangerous environments. Therefore authors of this article focused on more detailed working with this material. The authors describe the use of PDMS polymer for the light transmission over short distances (up to tens of centimeters). PDMS offers good prerequisites (mechanical properties) for the creating cylindrical lighting waveguide e.g. for the purpose of the automotive industry. The objective is to determine the maximum bending radius of the cylindrical waveguide of polydimethylsiloxane for different wavelengths of the visible spectrum and thus extend the knowledge for subsequent use in lighting. The created cylindrical waveguide consist of a core and a cladding. Cladding was formed by a PDMS having a lower refractive index in order to respect the condition of total reflection.

  20. Coastal Flooding in Florida's Big Bend Region with Application to Sea Level Rise Based on Synthetic Storms Analysis

    Directory of Open Access Journals (Sweden)

    Scott C. Hagen Peter Bacopoulos

    2012-01-01

    Full Text Available Flooding is examined by comparing maximum envelopes of water against the 0.2% (= 1-in-500-year return-period flooding surface generated as part of revising the Federal Emergency Management Agency¡¦s flood insurance rate maps for Franklin, Wakulla, and Jefferson counties in Florida¡¦s Big Bend Region. The analysis condenses the number of storms to a small fraction of the original 159 used in production. The analysis is performed by assessing which synthetic storms contributed to inundation extent (the extent of inundation into the floodplain, coverage (the overall surface area of the inundated floodplain and the spatially variable 0.2% flooding surface. The results are interpreted in terms of storm attributes (pressure deficit, radius to maximum winds, translation speed, storm heading, and landfall location and the physical processes occurring within the natural system (storms surge and waves; both are contextualized against existing and new hurricane scales. The approach identifies what types of storms and storm attributes lead to what types of inundation, as measured in terms of extent and coverage, in Florida¡¦s Big Bend Region and provides a basis in the identification of a select subset of synthetic storms for studying the impact of sea level rise. The sea level rise application provides a clear contrast between a dynamic approach versus that of a static approach.

  1. Rupture prediction for induction bends under opening mode bending with emphasis on strain localization

    International Nuclear Information System (INIS)

    Mitsuya, Masaki; Sakanoue, Takashi

    2015-01-01

    This study focuses on the opening mode of induction bends; this mode represents the deformation outside a bend. Bending experiments on induction bends are shown and the manner of failure of these bends was investigated. Ruptures occur at the intrados of the bends, which undergo tensile stress, and accompany the local reduction of wall thickness, i.e., necking that indicates strain localization. By implementing finite element analysis (FEA), it was shown that the rupture is dominated not by the fracture criterion of material but by the initiation of strain localization that is a deformation characteristic of the material. These ruptures are due to the rapid increase of local strain after the initiation of strain localization and suddenly reach the fracture criterion. For the evaluation of the deformability of the bends, a method based on FEA that can predict the displacement at the rupture is proposed. We show that the yield surface shape and the true stress–strain relationship after uniform elongation have to be defined on the basis of the actual properties of the bend material. The von Mises yield criterion, which is commonly used in cases of elastic–plastic FEA, could not predict the rupture and overestimated the deformability. In contrast, a yield surface obtained by performing tensile tests on a biaxial specimen could predict the rupture. The prediction of the rupture was accomplished by an inverse calibration method that determined the true stress-strain relationship after uniform elongation. As an alternative to the inverse calibration, a simple extrapolation method of the true stress-strain relationship after uniform elongation which can predict the rupture is proposed. - Highlights: • A method based on FEA that can predict the displacement at the rupture is proposed. • The yield surface shape and the true stress–strain have to be defined precisely. • The von Mises yield criterion overestimated the deformability. • The ruptures are due to the

  2. Stresses in a curved pipe subject to an in-plane bending moment

    International Nuclear Information System (INIS)

    Hofmann, E.; Heeschen, U.

    1979-01-01

    The design of the KWU-primary component supports is mainly defined by the loads of the postulated pipe breaks. To estimate the maximum loading of a component support it is necessary to know the maximum in-plane bending moment (opening and closing) that can be transmitted by a pipe bend. Another reason for such information is that the displacements and distortions of the components cause higher stresses in elbows than in straight pipes. With a detailed knowledge of the deformation characteristic of a pipe bend an integrity analysis could be done without an expensive plastic system analysis. With this purpose in mind experiments were performed with straight pipes and pipe bends of different dimensions subject to in-plane bending moments. The experimental results give the ratio between the maximum transmittable moment of a pipe bend to that of a straight pipe or, the distortion of the end cross-sections and the flattening of the elbow cross-section. An attempt is made to derive simple expressions for estimating the behaviour at pipe elbows. Parallel to the experiments calculations were done for the straight pipe and elbow with a finite difference code with plastic capabilities. The results of the experiment and calculation are compared with the formulas of the ASME-Code section III subjection NB. (orig.)

  3. Elastic-plastic dynamic analysis of a reactor building

    International Nuclear Information System (INIS)

    Umemura, Hajime; Tanaka, Hiroshi.

    1976-01-01

    The basic characteristics of the dynamic response of a reactor building to severe earthquake ground motion are very important for the evaluation of the safety of nuclear plant systems. A computer program for elastic-plastic dynamic analysis of reactor buildings using lumped mass models is developed. The box and cylindrical walls of boiling water reactor buildings are treated as vertical beams. The nonlinear moment-rotation and shear force-shear deformation relationships of walls are based in part upon the experiments of prototype structures. The geometrical non-linearity of the soil rocking spring due to foundation separation is also considered. The nonlinear equation of motion is expressed in incremental form using tangent stiffness matrices, following the algorithm developed by E.L. Wilson et al. The damping matrix in the equation is formulated as the combination of the energy evaluation method and Penzien-Wilson's approach to accomodate the different characteristics of soil and building damping. The analysis examples and the comparison of elastic and elastic-plastic analysis results are presented. (auth.)

  4. Ramifications of structural deformations on collapse loads of critically cracked pipe bends under in-plane bending and internal pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sasidharan, Sumesh; Arunachalam, Veerappan; Subramaniam, Shanmugam [Dept. of Mechanical Engineering, National Institute of Technology, Tiruchirappalli (India)

    2017-02-15

    Finite-element analysis based on elastic-perfectly plastic material was conducted to examine the influence of structural deformations on collapse loads of circumferential through-wall critically cracked 90 .deg. pipe bends undergoing in-plane closing bending and internal pressure. The critical crack is defined for a through-wall circumferential crack at the extrados with a subtended angle below which there is no weakening effect on collapse moment of elbows subjected to in-plane closing bending. Elliptical and semioval cross sections were postulated at the bend regions and compared. Twice-elastic-slope method was utilized to obtain the collapse loads. Structural deformations, namely, ovality and thinning, were each varied from 0% to 20% in steps of 5% and the normalized internal pressure was varied from 0.2 to 0.6. Results indicate that elliptic cross sections were suitable for pipe ratios 5 and 10, whereas for pipe ratio 20, semioval cross sections gave satisfactory solutions. The effect of ovality on collapse loads is significant, although it cancelled out at a certain value of applied internal pressure. Thinning had a negligible effect on collapse loads of bends with crack geometries considered.

  5. Fabrication and Analysis Signal Optical Fiber Sensor Based On Bend Loss for Weight in Motion Applications

    Science.gov (United States)

    Aftah Syukron, Ahmad; Marzuki, Ahmad; Setyawan, Ary

    2017-11-01

    Road network plays very important role in economic development. Overweight is one of the main factors contributing to road damage. To minimize this factor, road authority has to make sure that all vehicles operate in according to maximum vehicle regulation set by the government. The one solution can use from this problem is Weight in motion (WIM) technology. WIM technology allows measuring vehicle weight quickly. The sensor is one of the important components in the WIM system. This paper presents a model of WIM fiber sensor work based on bend loss. Fiber sensor has made by coiling optical fiber. Coiling optical fiber has managed in the elliptical shape rubber coil. Rubber coil then is planted in the pad of sensor. The principle of this sensor is a detecting of the shift light intensity output of optical fiber when the vehicles a passing through on fiber sensor. Loading was carried out using loaded truck model. Data was carried out with variations of load and load positions in the truck. The results can be concluded that the shift light intensity is greater with the more shift loads. The loader of the truck has also resulted in the greater loss. Loads in the truck distributed on the axles due to the position of loads.

  6. Vertical bending strength and torsional rigidity analysis of formula student car chassis

    Science.gov (United States)

    Hazimi, Hashfi; Ubaidillah, Setiyawan, Adi Eka Putra; Ramdhani, Hanief Cahya; Saputra, Murnanda Zaesy; Imaduddin, Fitrian

    2018-02-01

    Formula Society of Automotive Engineers (FSAE) is a competition for students to construct formula student car. One of an essential part of a formula student car is its chassis. Chassis is an internal vehicle frame which holds all another part of the vehicle and secures the driver. The team have to design their chassis and tests their design to achieve the best chassis that fulfill the regulation. This paper contains chassis design from Bengawan FSAE Team and some FEA tests to find out the Tensile Strength, Torsional Rigidity, and Von Misses Stress of Formula SAE car. Torsional rigidity was found by applying the static torsional test. The results from torsional rigidity test are a maximum deformation of 9.9512 mm with 1.7064 safety factor, and 35.935 MPa maximum Von Misses Stress. Moreover, then the result of the vertical bending strength test is 8.1214 mm max deformation with safety factor 4.2717, and 29.226 MPa maximum Von Misses Stress.

  7. A New Hyperbolic Shear Deformation Theory for Bending Analysis of Functionally Graded Plates

    Directory of Open Access Journals (Sweden)

    Tahar Hassaine Daouadji

    2012-01-01

    Full Text Available Theoretical formulation, Navier’s solutions of rectangular plates based on a new higher order shear deformation model are presented for the static response of functionally graded plates. This theory enforces traction-free boundary conditions at plate surfaces. Shear correction factors are not required because a correct representation of transverse shearing strain is given. Unlike any other theory, the number of unknown functions involved is only four, as against five in case of other shear deformation theories. The mechanical properties of the plate are assumed to vary continuously in the thickness direction by a simple power-law distribution in terms of the volume fractions of the constituents. Numerical illustrations concern flexural behavior of FG plates with metal-ceramic composition. Parametric studies are performed for varying ceramic volume fraction, volume fractions profiles, aspect ratios, and length to thickness ratios. Results are verified with available results in the literature. It can be concluded that the proposed theory is accurate and simple in solving the static bending behavior of functionally graded plates.

  8. Nonlinear analysis of AS4/PEEK thermoplastic composite laminate using a one parameter plasticity model

    Science.gov (United States)

    Sun, C. T.; Yoon, K. J.

    1990-01-01

    A one-parameter plasticity model was shown to adequately describe the orthotropic plastic deformation of AS4/PEEK (APC-2) unidirectional thermoplastic composite. This model was verified further for unidirectional and laminated composite panels with and without a hole. The nonlinear stress-strain relations were measured and compared with those predicted by the finite element analysis using the one-parameter elastic-plastic constitutive model. The results show that the one-parameter orthotropic plasticity model is suitable for the analysis of elastic-plastic deformation of AS4/PEEK composite laminates.

  9. Supplement Analysis for the Watershed Management Program EIS--Tapteal Bend Riparian Corridor Restoration Project

    Energy Technology Data Exchange (ETDEWEB)

    N/A

    2004-08-11

    the applicable terms and conditions identified in the ESA Consultation Biological Opinion (BO) and Magnuson-Stevens Fishery Conservation and Management Act Essential Fish Habitat Consultation, for BPA's Habitat Improvement Program (HIP), the Tapteal Bend Restoration Project meets the requirements of consistency and no further consultation is required. ESA listed fish may be present in the project vicinity but will not be affected because the project does not involve instream work. In complying with the requirements of Section 106 of the National Historic Preservation Act, BPA contracted with the Cultural Resources Protection Program of the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) for cultural resource survey work. Shawn Steinmetz prepared a report (December 15, 2002) concluding that there were only two isolated finds in the project area. BPA and the Washington Office of Archaeology and Historic Preservation have concurred with the conclusions and recommendations set out in the report and the determination that no historic properties will be affected by the current project as proposed (January 31, 2003). It was recommended that a cultural resource monitor be present during ground disturbing activities. In the unlikely event that archaeological material is discovered during project implementation, an archaeologist should be notified immediately and work halted in the vicinity of the finds until they can be inspected and assessed. Standard water quality protection procedures and Best Management Practices should be followed during the implementation of the Tapteal Bend Restoration project. No construction is authorized to begin until the proponent has obtained all applicable local, state, and federal permits and approvals.

  10. Finite element analysis of elasto-plastic tee joints

    International Nuclear Information System (INIS)

    Powell, G.H.

    1974-09-01

    The theory and computational procedures used in the computer program B169TJ/EP for the analysis of elasto-plastic tee joints are described, and detailed user's guide is presented. The program is particularly applicable to joints conforming to the ANSI B16.9 Manufacturing Standard, but can also be applied to other joint geometries. The joint may be loaded by internal pressure and by arbitrary combinations of applied forces and moments at the ends of the branch and run pipes, and the loading sequence may be arbitrary. The joint material is assumed to yield according to the von Mises criterion, and to exhibit either linear kinematic hardening or nonlinear isotropic hardening after yield. The program makes use of the finite element and mesh generation procedures previously applied in the elastic stress analysis program B16.9TJ/ SA, with minor modifications. (U.S.)

  11. Finite element elastic-plastic analysis of LMFBR components

    International Nuclear Information System (INIS)

    Levy, A.; Pifko, A.; Armen, H. Jr.

    1978-01-01

    The present effort involves the development of computationally efficient finite element methods for accurately predicting the isothermal elastic-plastic three-dimensional response of thick and thin shell structures subjected to mechanical and thermal loads. This work will be used as the basis for further development of analytical tools to be used to verify the structural integrity of liquid metal fast breeder reactor (LMFBR) components. The methods presented here have been implemented into the three-dimensional solid element module (HEX) of the Grumman PLANS finite element program. These methods include the use of optimal stress points as well as a variable number of stress points within an element. This allows monitoring the stress history at many points within an element and hence provides an accurate representation of the elastic-plastic boundary using a minimum number of degrees of freedom. Also included is an improved thermal stress analysis capability in which the temperature variation and corresponding thermal strain variation are represented by the same functional form as the displacement variation. Various problems are used to demonstrate these improved capabilities. (Auth.)

  12. Numerical simulation for hot forming of head plates and pipe bending

    International Nuclear Information System (INIS)

    Ohta, Takahiro; Itoh, Shingo; Yamasaki, Masato; Miura, Akira.

    1995-01-01

    A great deal of time could be saved if physical experiments were replaced by numerical simulations in the development of new forming processes. In this paper, explicit dynamic finite element methods for the hot forming of head plates and pipe bending are investigated. In the case of hemispherical hot forming, the predicted formed shapes and the punch force by thermo elastic plastic analysis are very similar to those found by experiment. Moreover, it is shown that wrinkles occuring in the hot forming process can be predicted. And we can also simulate pipe bending processes by numerical analysis. (author)

  13. Plasticity theory

    CERN Document Server

    Lubliner, Jacob

    2008-01-01

    The aim of Plasticity Theory is to provide a comprehensive introduction to the contemporary state of knowledge in basic plasticity theory and to its applications. It treats several areas not commonly found between the covers of a single book: the physics of plasticity, constitutive theory, dynamic plasticity, large-deformation plasticity, and numerical methods, in addition to a representative survey of problems treated by classical methods, such as elastic-plastic problems, plane plastic flow, and limit analysis; the problem discussed come from areas of interest to mechanical, structural, and

  14. Statistical Analysis of 3-Point Bending Properties of Polymer Concretes Made From Marble Powder Waste, Sand Grains, and Polyester Resin

    Science.gov (United States)

    Benzannache, N.; Bezazi, A.; Bouchelaghem, H.; Boumaaza, M.; Amziane, S.; Scarpa, F.

    2018-01-01

    The mechanical performance of concrete polymer beams subjected to 3-point bending was investigated. The polymer concrete incorporates marble powder waste and quarry sand. The results obtained showed that the type of sand, and amount of marble powder and sand aggregate affected the resistance of the polymer concrete beams significantly. The marble waste increased their bending strength by reducing the porosity of polymer concrete.

  15. Plastic collapse and energy absorption of circular filled tubes under quasi-static loads by computational analysis

    Energy Technology Data Exchange (ETDEWEB)

    Beng, Yeo Kiam; Tzeng, Woo Wen [Universiti Malaysia Sabah, Sabah (Malaysia)

    2017-02-15

    This study presents the finite element analysis of plastic collapse and energy absorption of polyurethane-filled aluminium circular tubes under quasi-static transverse loading. Increasing focuses were given to impact damage of structures where energy absorbed during impact could be controlled to avoid total structure collapse of energy absorbers and devices designed to dissipate energy. ABAQUS finite element analysis application was utilized for modelling and simulating the polyurethane-filled aluminium tubes, different set of diameterto- thickness ratios and span lengths, subjected to transverse three-point-bending load. Different sets of polyurethane-filled aluminium tubes subjected to the transverse loading were modelled and simulated. The failure modes and mechanisms of filled tubes and its capabilities as energy absorbers to further improve and strengthening of empty tube were also identified. The results showed that plastic deformation response was affected by the geometric constraints and parameters of the specimens. The diameter-to-thickness ratio and span lengths had shown to play crucial role in optimizing the PU-filled tube as energy absorber.

  16. Plastic recycling in the Nordics: A value chain market analysis.

    Science.gov (United States)

    Milios, Leonidas; Holm Christensen, Lena; McKinnon, David; Christensen, Camilla; Rasch, Marie Katrine; Hallstrøm Eriksen, Mikael

    2018-06-01

    There is low utilisation of plastic waste in the Nordic region and only a fraction of plastic materials go back into production processes through reuse and recycling practices. This paper aims to increase knowledge concerning factors that inhibit demand for recycled plastics, and to identify critical barriers for plastic recycling across the regional plastics value chain. A literature review and targeted interviews with key actors across the plastics value chain enabled the mapping of interactions between the major actors and identified hotspots that act as barriers to the flow of plastic materials. Barriers identified include the lack of both supply and demand of recycled plastic and are mainly attributed to the fragmented market of secondary materials. The main hotspots identified are the low demand due to price considerations, insufficient traceability and transparency in value chain transactions, and general design deficiencies in the recyclability of products. Value chain coordination is considered as the most important intervention by the interviewees, followed by the need for increased investment in innovation and technology development. Complementary measures that could counteract the identified barriers include public procurement for resource efficiency, ban on the incineration of recyclable materials, and specifications on the design of plastic products for reducing the number of different polymers, and the number and usage of additives. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Assessment of effect of reinforcement on plastic limit load of branch junction

    International Nuclear Information System (INIS)

    Myung, Man Sik; Kim, Yun Jae; Yoon, Ki Bong

    2009-01-01

    The present work provides effects of reinforcement shape and area on plastic limit loads of branch junctions, based on detailed three-dimensional finite element limit analysis and small strain FE limit analyses assuming elastic-perfectly plastic material behavior. Three types of loading are considered; internal pressure, in-plane bending on the branch pipe and in-plane bending on the run pipe. It is found that reinforcement is the most effective in the case when (in-plane/out-of-plane) bending is applied to the branch pipe. When bending is applied to the run pipe, reinforcement is less effective, compared to the case when bending is applied to the branch pipe. The reinforcement effect is the least effective for internal pressure.

  18. Plastic Indentation Analysis Used in Study of Colliding Robotic Elements

    Directory of Open Access Journals (Sweden)

    Florina Carmen Ciornei

    2014-06-01

    Full Text Available In robotic system there are frequent situations when on the robotic parts percutions develop. The impact plastic imprints are unique source of data remaining after collision, but complications occur in the analysis and the work models a general impact and presents the manner of processing the experimental data. The paper presents the characteristics occurring in the analysis of the indentation remnant after the oblique impact between a free falling ball and the surface of an inclined metallic prism. A series of difficulties arise while trying to approximate the collision’s imprint profile with a parabola having oblique symmetry axis. Both these impediments and the manner of surmounting them are presented. Finally, the impasse that takes place in the actual analysis of an imprint profile is presented. A first method of surpassing this aspect uses the intrinsic characteristics of osculating circle in a point of the profile is applicable only for smooth signals. The second proposed method is applied to the real signal and provides fine results.

  19. Plastic limit analysis with non linear kinematic strain hardening for metalworking processes applications

    International Nuclear Information System (INIS)

    Chaaba, Ali; Aboussaleh, Mohamed; Bousshine, Lahbib; Boudaia, El Hassan

    2011-01-01

    Limit analysis approaches are widely used to deal with metalworking processes analysis; however, they are applied only for perfectly plastic materials and recently for isotropic hardening ones excluding any kind of kinematic hardening. In the present work, using Implicit Standard Materials concept, sequential limit analysis approach and the finite element method, our objective consists in extending the limit analysis application for including linear and non linear kinematic strain hardenings. Because this plastic flow rule is non associative, the Implicit Standard Materials concept is adopted as a framework of non standard plasticity modeling. The sequential limit analysis procedure which considers the plastic behavior with non linear kinematic strain hardening as a succession of perfectly plastic behavior with yielding surfaces updated after each sequence of limit analysis and geometry updating is applied. Standard kinematic finite element method together with a regularization approach is used for performing two large compression cases (cold forging) in plane strain and axisymmetric conditions

  20. Plasticity around an Axial Surface Crack in a Cylindrical Shell

    DEFF Research Database (Denmark)

    Krenk, Steen

    1979-01-01

    of the yield zone. The model is used to analyse published test data on surface cracked pressurised pipes. The analysis consists in COD evaluation and estimate of failure as a consequence of plastic instability. A method is proposed which deals with the problem by simultaneous analysis of a number of cracks......This paper presents a plasticity model for deep axial surface cracks in pressurised pipes. The model is used in an investigation of the relative merits of fracture criteria based on COD and plastic instability. Recent investigations have shown that the inconsistency of the singular bending stress...... on the bending stresses is considerable. In the case of surface cracks moments are induced due to the eccentricity of the crack and transverse shear effects should therefore be included. A plasticity model for a rectangular axial surface crack is developed. Like a previous surface crack model by Erdogen...

  1. Fatigue analysis of flexible pipes using alternative element types and bend stiffener data

    OpenAIRE

    Chen, Minghao

    2011-01-01

    The flexible pipe is a vital part of a floating production system. The lifetime of a flexible riser system is crucial for the Health Safety and Environment (HSE) management. As a result of this, it is very necessary to carry out research on the lifetime of flexible pipe. In this thesis we formalized analysis on flexible pipes, utilizing the finite element analysis software BFLEX 2010, developed by MARINTEK. Chapter 1 describes basic knowledge about flexible pipe and relevant facilities. C...

  2. A Sensitivity Analysis On The Springback Behavior Of The Unconstrained Bending Problem

    International Nuclear Information System (INIS)

    Meinders, T.; Konter, A.W.A.; Meijers, S.E.; Atzema, E.H.; Kappert, H.

    2005-01-01

    Sheet metal forming software is commonly used in the automotive and sheet metal sectors to support the design stage. However, the ability of the currently available software to accurately predict springback is limited. A sensitivity analysis of the springback behavior of a simple product is performed to gain more knowledge into the various factors contributing to the predictability of springback. The sensitivity analysis comprises both numerical and physical aspects and the most important results are reported in this paper

  3. ASSESSMENT OF PLASTIC FLOWS AND STOCKS IN SERBIA USING MATERIAL FLOW ANALYSIS

    Directory of Open Access Journals (Sweden)

    Goran Vujić

    2010-01-01

    Full Text Available Material flow analysis (MFA was used to assess the amounts of plastic materials flows and stocks that are annually produced, consumed, imported, exported, collected, recycled, and disposed in the landfills in Serbia. The analysis revealed that approximatelly 269,000 tons of plastic materials are directly disposed in uncontrolled landfills in Serbia without any preatretment, and that siginificant amounts of these materials have already accumulated in the landfills. The substantial amounts of landfilled plastics represent not only a loss of valuable recourses, but also pose a seriuos treath to the environment and human health, and if the trend of direct plastic landfilling is continued, Serbia will face with grave consecequnces.

  4. Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis

    OpenAIRE

    Pflieger, Maryline; Makorič, Petra; Kovač Viršek, Manca; Koren, Špela

    2017-01-01

    Plastic resin pellets, categorized as microplastics (≤5 mm in diameter), are small granules that can be unintentionally released to the environment during manufacturing and transport. Because of their environmental persistence, they are widely distributed in the oceans and on beaches all over the world. They can act as a vector of potentially toxic organic compounds (e.g., polychlorinated biphenyls) and might consequently negatively affect marine organisms. Their possible impacts alo...

  5. MR elastography of the liver at 3 T with cine-tagging and bending energy analysis: preliminary results

    International Nuclear Information System (INIS)

    Watanabe, Haruo; Kanematsu, Masayuki; Kondo, Hiroshi; Goshima, Satoshi; Kajita, Kimihiro; Kitagawa, Teruhiko; Suzuki, Yuriko; Bae, Kyongtae T.; Hirose, Yoshinobu; Miotani, Seiki; Zhou, Xiangrong; Fujita, Hiroshi

    2010-01-01

    To preliminarily evaluate the feasibility and usefulness of MR elastography of the liver at 3 T with cine-tagging and bending energy (BE) analysis for the evaluation of hepatic fibrosis. Twenty-two patients underwent MR elastography with four different cine-tagging grids on the liver (16- or 20-mm sagittal or coronal). Nine images serially obtained during 1-s of exhalation were analyzed to define coordinates of grid intersections. BE values were calculated using the thin-plate spline method. BE values were compared among patient groups with different fibrosis stage thresholds. In the 22 patients, six had a fibrosis score of F0, one had F1, seven had F2, three had F3, and five had F4. Mean BE value with 16-mm sagittal grid was greater with fibrosis score F0 (1.54 ± 0.63) than with ≥F1 (0.97 ± 0.12, P = 0.013) as well as with ≤F1 (1.48 ± 0.60) than with ≥F2 (0.96 ± 0.36, P = 0.019). Our results showed that MR elastography with 16-mm sagittal grid and BE analysis had a potential in discrimination for the patients with moderate or advanced hepatic fibrosis from those with healthy liver or slight fibrosis. (orig.)

  6. Finite element analysis of cylindrical indentation for determining plastic properties of materials in small volumes

    International Nuclear Information System (INIS)

    Lu, Y Charles; Kurapati, Siva N V R K; Yang Fuqian

    2008-01-01

    The cylindrical indentation is analysed, using the finite element method, for determining the plastic properties of elastic-plastic materials and the effect of strain hardening. The results are compared with those obtained from spherical indentation, the commonly used technique for measuring plastic properties of materials in small volumes. The analysis shows that the deformation under a cylindrical indenter quickly reaches a fully plastic state and that the size (diameter) of the plastic zone remains constant during further indentation. The indentation load is proportional to the indentation depth at large indentation depth, from which the indentation pressure P m at the onset of yielding can be readily extrapolated. The analysis of cylindrical indentation suggests that it does not need parameters such as impression radius (a) and contact stiffness (S) for determining the plastic behaviour of materials. Thus, the cylindrical indentation can suppress the uncertainties in measuring material properties

  7. A sensitivity analysis on the springback behavior of the Unconstrained Bending Problem

    NARCIS (Netherlands)

    Meinders, Vincent T.; Konter, A.W.A.; Meijers, S.E.; Atzema, E.H.; Kappert, H.

    2006-01-01

    Sheet metal forming software is commonly used in the automotive and sheet metal sectors to support the design stage. However, the ability of the currently available software to accurately predict springback is limited. A sensitivity analysis of the springback behavior of a simple product is

  8. Experimental and Numerical Investigations of Applying Tip-bottomed Tool for Bending Advanced Ultra-high Strength Steel Sheet

    Science.gov (United States)

    Mitsomwang, Pusit; Borrisutthekul, Rattana; Klaiw-awoot, Ken; Pattalung, Aran

    2017-09-01

    This research was carried out aiming to investigate the application of a tip-bottomed tool for bending an advanced ultra-high strength steel sheet. The V-die bending experiment of a dual phase steel (DP980) sheet which had a thickness of 1.6 mm was executed using a conventional bending and a tip-bottomed punches. Experimental results revealed that the springback of the bent worksheet in the case of the tip-bottomed punch was less than that of the conventional punch case. To further discuss bending characteristics, a finite element (FE) model was developed and used to simulate the bending of the worksheet. From the FE analysis, it was found that the application of the tip-bottomed punch contributed the plastic deformation to occur at the bending region. Consequently, the springback of the worksheet reduced. In addition, the width of the punch tip was found to affect the deformation at the bending region and determined the springback of the bent worksheet. Moreover, the use of the tip-bottomed punch resulted in the apparent increase of the surface hardness of the bent worksheet, compared to the bending with the conventional punch.

  9. Stress analysis and fatigue life prediction for a U-bend steam generator tube

    International Nuclear Information System (INIS)

    Cheng Weili; Finnie, I.

    1996-01-01

    An analysis is carried out to determine the stresses in a steam generator tube that failed by fatigue. Using data available for the failed tube and for failures in two similar steam generators, the magnitudes of the alternating and mean stresses produced during operation are estimated. The cause for the early fatigue failure is shown to be the high mean stress caused by denting of the tube in the location where it passed through the tube sheet. (orig.)

  10. comparison of elastic-plastic FE method and engineering method for RPV fracture mechanics analysis

    International Nuclear Information System (INIS)

    Sun Yingxue; Zheng Bin; Zhang Fenggang

    2009-01-01

    This paper described the FE analysis of elastic-plastic fracture mechanics for a crack in RPV belt line using ABAQUS code. It calculated and evaluated the stress intensity factor and J integral of crack under PTS transients. The result is also compared with that by engineering analysis method. It shows that the results using engineering analysis method is a little larger than the results using FE analysis of 3D elastic-plastic fracture mechanics, thus the engineering analysis method is conservative than the elastic-plastic fracture mechanics method. (authors)

  11. Spatial Analysis of Potentially Preventable Pneumonia and Asthma Hospitalizations for Children in the Texas Coastal Bend Area

    Science.gov (United States)

    Lin, Na

    families and particularly Hispanic fathers. Air pollution and temperature analysis revealed that high concentrations of Ozone and Sulfur Dioxide likely cause pneumonia and asthma hospitalization of children. Combined with dramatic change in temperature, air pollution played an important role in the hospitalization of pneumonia and asthma plagued children in the coastal bend area. The human subject survey showed that the time children spent outdoors was highly positive correlated with asthma rate.

  12. Bending analysis of embedded nanoplates based on the integral formulation of Eringen's nonlocal theory using the finite element method

    Science.gov (United States)

    Ansari, R.; Torabi, J.; Norouzzadeh, A.

    2018-04-01

    Due to the capability of Eringen's nonlocal elasticity theory to capture the small length scale effect, it is widely used to study the mechanical behaviors of nanostructures. Previous studies have indicated that in some cases, the differential form of this theory cannot correctly predict the behavior of structure, and the integral form should be employed to avoid obtaining inconsistent results. The present study deals with the bending analysis of nanoplates resting on elastic foundation based on the integral formulation of Eringen's nonlocal theory. Since the formulation is presented in a general form, arbitrary kernel functions can be used. The first order shear deformation plate theory is considered to model the nanoplates, and the governing equations for both integral and differential forms are presented. Finally, the finite element method is applied to solve the problem. Selected results are given to investigate the effects of elastic foundation and to compare the predictions of integral nonlocal model with those of its differential nonlocal and local counterparts. It is found that by the use of proposed integral formulation of Eringen's nonlocal model, the paradox observed for the cantilever nanoplate is resolved.

  13. Numerical analysis of developing turbulent flow in a U-bend of strong curvature with rib-roughened walls

    International Nuclear Information System (INIS)

    Sugiyama, Hitoshi; Watanabe, Chiriki

    2003-01-01

    Numerical analysis has been performed for three-dimensional developing turbulent flow in the U-bend of strong curvature with rib-roughened walls by using an algebraic Reynolds stress model. In this calculation, the algebraic Reynolds stress model is adopted in order to predict preciously Reynolds stresses and boundary fitted-coordinate system is introduced as the method for coordinate transformation to set exactly boundary conditions along complicated shape in rib-roughed walls. Calculated results of mean velocity and Reynolds stresses are compared with the experimental data in order to examine the validity of the presented numerical method and the algebraic Reynolds stress model. It has been pointed out as a characteristic feature from the experimental result that the maximum velocity appears near the inner wall of curved duct, which phenomenon is not recognized in mild curved duct. The present method could predict such velocity profiles correctly and reproduce the separated flow generated near the outlet cross section of curved duct. Adding to this, calculated results show clearly that the generation of maximum velocity near a inner wall is caused by pressure driven secondary flow which moves to inner wall from outer wall along symmetrical axis. As for the comparison of Reynolds stresses, the present turbulent model relatively predicts the experimental data well except for the flow separated region which is located near the outlet cross section of curved duct. (author)

  14. Analysis of a bending test on a full-scale PWR hot leg elbow containing a surface crack

    Energy Technology Data Exchange (ETDEWEB)

    Delliou, P. le [Electricite de France, EDF, 77 - Moret-sur-Loing (France). Dept. MTC; Julisch, P.; Hippelein, K. [Stuttgart Univ. (Germany). Staatliche Materialpruefungsanstalt; Bezdikian, G. [Electricite de France, EDF, 92 - Paris la Defense (France). Direction Production Transport

    1998-11-01

    EDF, in co-operation with Framatome, has conducted a large research programme on the mechanical behaviour of thermally aged cast duplex stainless steel elbows, which are part of the main primary circuit of French PWR. One important task of this programme consisted of testing a full-scale PWR hot leg elbow. The elbow contained a semi-elliptical circumferential notch machined on the outer surface of the intrados as well as casting defects located on the flanks. To simulate the end-of-life condition of the component regarding material toughness, it had undergone a 2400 hours ageing heat treatment at 400 C. The test preparation and execution, as well as the material characterization programme, were committed to MPA. The test was conducted under constant internal pressure and in-plane bending (opening mode) at 200 C. For safety reasons, it took place on an open air-site: the Meppen military test ground. At the maximum applied moment (6000 kN.m), the notch did not initiate. This paper presents the experimental results and the fracture mechanics analysis of the test, based on finite element calculations. (orig.)

  15. Experimental and numerical analysis of pre-compressed masonry walls in two-way-bending with second order effects

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Gabriele, E-mail: milani@stru.polimi.it [Department of Architecture, Built Environment and Construction Engineering (ABC), Politecnico diMilano, Piazza Leonardo da Vinci 32, 20133 Milan (Italy); Olivito, Renato S. [Dipartimento di Ingegneria Civile - Università della Calabria Via P Bucci 39 B - 87036 RENDE (CS) (Italy); Tralli, Antonio [Department of Engineering, University of Ferrara, Via Saragat 1, 44100 Ferrara (Italy)

    2014-10-06

    The buckling behavior of slender unreinforced masonry (URM) walls subjected to axial compression and out-of-plane lateral loads is investigated through a combined experimental and numerical homogenizedapproach. After a preliminary analysis performed on a unit cell meshed by means of elastic FEs and non-linear interfaces, macroscopic moment-curvature diagrams so obtained are implemented at a structural level, discretizing masonry by means of rigid triangular elements and non-linear interfaces. The non-linear incremental response of the structure is accounted for a specific quadratic programming routine. In parallel, a wide experimental campaign is conducted on walls in two way bending, with the double aim of both validating the numerical model and investigating the behavior of walls that may not be reduced to simple cantilevers or simply supported beams. Panels investigated are dry-joint in scale square walls simply supported at the base and on a vertical edge, exhibiting the classical Rondelet’s mechanism. The results obtained are compared with those provided by the numerical model.

  16. Experimental and numerical analysis of pre-compressed masonry walls in two-way-bending with second order effects

    International Nuclear Information System (INIS)

    Milani, Gabriele; Olivito, Renato S.; Tralli, Antonio

    2014-01-01

    The buckling behavior of slender unreinforced masonry (URM) walls subjected to axial compression and out-of-plane lateral loads is investigated through a combined experimental and numerical homogenizedapproach. After a preliminary analysis performed on a unit cell meshed by means of elastic FEs and non-linear interfaces, macroscopic moment-curvature diagrams so obtained are implemented at a structural level, discretizing masonry by means of rigid triangular elements and non-linear interfaces. The non-linear incremental response of the structure is accounted for a specific quadratic programming routine. In parallel, a wide experimental campaign is conducted on walls in two way bending, with the double aim of both validating the numerical model and investigating the behavior of walls that may not be reduced to simple cantilevers or simply supported beams. Panels investigated are dry-joint in scale square walls simply supported at the base and on a vertical edge, exhibiting the classical Rondelet’s mechanism. The results obtained are compared with those provided by the numerical model

  17. Genetic Analysis of Micro-environmental Plasticity in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Morgante, Fabio; Sorensen, Daniel A; Sørensen, Peter

    Quantitative genetic models recognize the potential for genotype by environment interaction, whereby different genotypes have different plastic responses to changes in macro-environmental conditions. Recently, it has been recognized that micro-environmental plasticity (‘residual’ variance) may also...... be genetically variable. This study utilized the Drosophila Genetic Reference Panel (DGRP) to accurately estimate the genetic variance of micro-environmental plasticity for chill coma recovery time and startle response. Estimates of broad sense heritabilities for both traits are substantial (from 0.51 to 0.......77), of the same order as the heritability at the level of the trait mean for startle response and even larger for chill coma recovery. Genome wide association analyses identified molecular variants (from 15 to 31 depending on the sex and the trait) associated with micro-environmental plasticity. These findings...

  18. Plasticity analysis of nano-grain-sized NiAl alloy in an atomic scale

    International Nuclear Information System (INIS)

    Wang Jingyang; Wang Xiaowei; Rifkin, J.; Li Douxing

    2001-12-01

    The molecular dynamics method is used to simulate a uniaxial tensile deformation of 3.8nm nano-NiAl alloy with curved amorphous-like interfaces at 0K. Plastic deformation behaviour is studied by examining the strain-stress relationship and the microstructural evolution characteristic. Atomic level analysis showed that the micro-strain is essentially heterogeneous in simulated nano-phase samples. The plastic deformation is not only attributed to the plasticity of interfaces, but also accompanied with the plastic shear strain mechanism inside lattice distortion regions and grains. (author)

  19. ELASTIC-PLASTIC AND RESIDUAL STRESS ANALYSIS OF AN ALUMINUM DISC UNDER INTERNAL PRESSURES

    Directory of Open Access Journals (Sweden)

    Numan Behlül BEKTAŞ

    2004-02-01

    Full Text Available This paper deals with elastic-plastic stress analysis of a thin aluminum disc under internal pressures. An analytical solution is performed for satisfying elastic-plastic stress-strain relations and boundary conditions for small plastic deformations. The Von-Mises Criterion is used as a yield criterion, and elastic perfectly plastic material is assumed. Elastic-plastic and residual stress distributions are obtained from inner radius to outer radius, and they are presented in tables and figures. All radial stress components, ?r, are compressive, and they are highest at the inner radius. All tangential stress components, ??, are tensile, and they are highest where the plastic deformation begins. Magnitude of the tangential residual stresses is higher than those the radial residual stresses.

  20. INJECTION MOLDING AND STRUCTURAL ANALYSIS IN METAL TO PLASTIC CONVERSION OF BOLTED FLANGE JOINT BY CAE

    Directory of Open Access Journals (Sweden)

    Marian Blaško

    2014-12-01

    Full Text Available Many metal parts in various applications are being replaced by plastic parts. There are several reasons for that depending on actual application - minimize part cost, enhance corrosion resistance, integrating more components into one part etc. Most important steps of metal to plastic conversion are material selection and design of plastic part. Plastic part has to withstand the same load as metal part. To fulfill this requirement fiber reinforced engineering plastics are often used. Also it is convenient to substitute heavy wall sections with ribbed structure to increase load-carrying ability of part and decrease cycle time, eliminate voids, sink marks etc. Mechanical properties of such part could be highly affected by fiber orientation. Results of fiber orientation from injection molding filling analysis can be used in stress analysis for better prediction of part response to mechanical load. Such coupled analysis is performed here in this case study on bolted flange joint.

  1. Static bending test after proximal femoral nail (PFN removal - in vitro analysis

    Directory of Open Access Journals (Sweden)

    Leonardo Morais Paiva

    Full Text Available Abstract Objective To evaluate, through biomechanical testing, the resistance to and energy required for the occurrence of proximal femoral fracture in synthetic bone after removal of a proximal femoral nail model (PFN, comparing the results obtained with a reinforcement technique using polymethylmethacrylate (PMMA. Methods Fifteen synthetic bones were used: five units for the control group (CG, five for the test group without reinforcement (TGNR, and five for the test group with reinforcement (TGR. The biomechanical analysis was performed simulating a fall on the trochanter using a servo-hydraulic machine. In the GC, the assay was performed with the PFN intact. In the TGNR and TGR groups, a model of PFN was introduced and the tests were performed in the TGNR, after simple removal of the synthesis material, and in the TGR, after removal of the same PFN model and filling of the cavity in the femoral neck with PMMA. Results All groups presented a basicervical fracture. The CG presented a mean of 1427.39 Newtons (N of maximum load and 10.14 Joules (J of energy for the occurrence of the fracture. The TGNR and TGR presented 892.14 N and 1477.80 N of maximum load, and 6.71 J and 11.99 J of energy, respectively. According to the Kruskal-Wallis ANOVA, there was a significant difference in the maximum load (p = 0.009 and energy (p = 0.007 between these groups. Conclusion The simple removal of a PFN in synthetic bone showed a significant reduction of the maximum load and energy for the occurrence of fracture, which were re-established with a reinforcement technique using PMMA.

  2. Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide.

    Science.gov (United States)

    Kim, Gun-Hee; Lee, Jeong-Won; Seo, Tae-Il

    2013-05-10

    Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this study, the mechanical characteristic analysis of the glass-reinforced plastic worm wheel, according to the contents of glass fiber, is performed by analytic and experimental methods. In the case of the glass fiber-reinforced resin, the orientation and contents of glass fibers can influence the mechanical properties. For the characteristic prediction of plastic worm wheel, computer-aided engineering (CAE) analysis processes such as structural and injection molding analysis were executed with the polyamide resin reinforcement glass fiber (25 wt %, 50 wt %). The injection mold for fabricating the prototype plastic worm wheel was designed and made to reflect the CAE analysis results. Finally, the durability of prototype plastic worm wheel fabricated by the injection molding process was evaluated by the experimental method and the characteristics according to the glass fiber contents.

  3. Neutron activation analysis for chemical characterization of Brazilian oxo-biodegradable plastics

    International Nuclear Information System (INIS)

    Mateus Eugenio Boscaro; De Nadai Fernandes, E.A.; Marcio Arruda Bacchi; Luis Gustavo Cofani dos Santos; Cofani dos Santos, S.N.S.; Sandra Mara Martins-Franchetti

    2015-01-01

    The chemical characterization of oxo-biodegradable plastic bags was performed by neutron activation analysis. The presence of several chemical elements (As, Br, Ca, Co, Cr, Fe, Hf, K, La, Na, Sb, Sc, Ta and Zn) with large variability of mass fractions amongst samples indicates that these plastics receive additives and may have been contaminated during manufacturing process thereby becoming potential environmental pollutants. (author)

  4. Separation and analysis of low molecular weight plasticizers in poly(vinyl chloride) tubes

    DEFF Research Database (Denmark)

    Wang, Qian; Storm, Birgit Kjærside

    2005-01-01

    ) and thermogravimetric analysis (TGA), as well as by studying the extracted low molecular weight plasticizers by gas chromatography/mass spectroscopy (GC/MS) and GC. It was found that the simple room temperature extraction in chloroform showed the best separation of plasticizers from the PVC matrix. Close results...

  5. Elasto-plastic strain analysis by a semi-analytical method

    Indian Academy of Sciences (India)

    Non-uniform taper bar; rotating disk; elasto-plastic strain analysis; loaded natural frequency. ... The location of initiation of elasto-plastic front and its growth are found to be functions of geometry of the bar and loading ... Sadhana | News.

  6. Comparative analysis of torsional and bending behavior through finite-element models of 5 Ni-Ti endodontic instruments.

    Science.gov (United States)

    Arbab-Chirani, Reza; Chevalier, Valérie; Arbab-Chirani, Shabnam; Calloch, Sylvain

    2011-01-01

    The objectives of this study were to compare numerically the bending and torsional mechanical behavior of 5 endodontic rotary Ni-Ti instruments with equivalent size and various designs for tapers, pitch, and cutting blades.First, the geometries of Hero (20/0.06), HeroShaper (20/0.06), ProFile (20/0.06), Mtwo (20/0.06), and ProTaper F1 were generated by finite element code. Then, the 2 most representative clinical loadings, i.e., bending and torsion, were studied with an ad hoc model for the superelasticity of Ni-Ti. Bending was generated by tip deflection and torsion by a constant twist-angle of the tip. Mechanical behavior of these 5 endodontic rotary Ni-Ti instruments could be evaluated and compared. Protaper F1 presented the greatest level of bending stress and torque. Hero and HeroShaper were more rigid than ProFile and Mtwo. This numerical comparison evaluated the effects of the geometrical parameters on the instrumental mechanical behavior. The 5 endodontic instruments, investigated in the present study, do not have the same bending and torsional mechanical behavior. Each clinician must be aware of these behavior differences so as to use the adequate file according to the clinical situation and to the manufacturer's recommendations. Copyright © 2011 Mosby, Inc. All rights reserved.

  7. Modeling and experimental analysis of the linear ultrasonic motor with in-plane bending and longitudinal mode.

    Science.gov (United States)

    Wan, Zhijian; Hu, Hong

    2014-03-01

    A novel linear ultrasonic motor based on in-plane longitudinal and bending mode vibration is presented in this paper. The stator of the motor is composed of a metal plate and eight piezoelectric ceramic patches. There are four long holes in the plate, designed for consideration of the longitudinal and bending mode coupling. The corresponding model is developed to optimize the mechanical and electrical coupling of the stator, which causes an ellipse motion at the contact tip of the stator when the composite vibrations with longitudinal and bending are excited. Its harmonic and transient responses are simulated and inspected. A prototype based on the model is fabricated and used to conduct experiments. Results show that the amplitude of the stator's contact tips is significantly increased, which helps to amplify the driving force and speed of the motor. It is therefore feasible to implement effective linear movement using the developed prototype. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Athermal design and analysis of glass-plastic hybrid lens

    Science.gov (United States)

    Yang, Jian; Cen, Zhaofeng; Li, Xiaotong

    2018-01-01

    With the rapid development of security market, the glass-plastic hybrid lens has gradually become a choice for the special requirements like high imaging quality in a wide temperature range and low cost. The reduction of spherical aberration is achieved by using aspherical surface instead of increasing the number of lenses. Obviously, plastic aspherical lens plays a great role in the cost reduction. However, the hybrid lens has a priority issue, which is the large thermal coefficient of expansion of plastic, causing focus shift and seriously affecting the imaging quality, so the hybrid lens is highly sensitive to the change of temperature. To ensure the system operates normally in a wide temperature range, it is necessary to eliminate the influence of temperature on the hybrid lens system. A practical design method named the Athermal Material Map is summarized and verified by an athermal design example according to the design index. It includes the distribution of optical power and selection of glass or plastic. The design result shows that the optical system has excellent imaging quality at a wide temperature range from -20 ° to 70 °. The method of athermal design in this paper has generality which could apply to optical system with plastic aspherical surface.

  9. A theoretical/experimental approach to determining the residual strength of corroded pipelines under combined pressure/bending loads

    International Nuclear Information System (INIS)

    Kanninen, M.F.; Roy, S.; Grigory, S.C.; Pagalthivarthi, K.V.; Maple, J.

    1992-01-01

    This paper reported on a study that examined the feasibility of developing a theoretically valid methodology for assessing the residual strength of corroded oil pipelines in combined pressure loading and axial bending conditions. Bending can occur due to local subsidence that can occur in moist soil, resulting in bending stresses that can equal or exceed the pressure-related stresses. The study involved a series of pipe testing, finite element analyses and shell theory modelling. The experiment performed to validate the modelling involved an artificially degraded 20 inch diameter X52 steel pipe that was subjected to pressure and bending loadings. The integration of the 3 technical activities demonstrated the feasibility of the proposed analysis methodology for determining the potential failure of oil and gas pipelines with metal loss. Predictions were found to be in good agreement with experimental results when the methodology was combined with criteria such as the instability of the effective plastic strain. 1 ref., 7 figs.

  10. Identification of non-linear kinematic hardening with bending and unbending tests in anisotropic sheet-metals

    International Nuclear Information System (INIS)

    Brunet, M.; Morestin, F.; Godereaux, S.

    2000-01-01

    An inverse identification technique is proposed based on bending-unbending experiments on anisotropic sheet-metal strips. The initial anisotropy theory of plasticity is extended to include the concept of combined isotropic and non-linear kinematic hardening. This theory is adopted to characterise the anisotropic hardening due to loading-unloading which occurs in sheet-metal forming processes. To this end, a specific bending-unbending apparatus has been built to provide experimental moment-curvature curves. The constant bending moment applied over the length of the specimen to determine numerically the strain-stress behaviour but without Finite Element Analysis. Four constitutive parameters have to be identified by an inverse approach. Our identification results show that bending-unbending tests are suitable to model quite accurately the constitutive behaviour of sheet metals under complex loading paths. (author)

  11. Cyclic plasticity models and application in fatigue analysis

    Science.gov (United States)

    Kalev, I.

    1981-01-01

    An analytical procedure for prediction of the cyclic plasticity effects on both the structural fatigue life to crack initiation and the rate of crack growth is presented. The crack initiation criterion is based on the Coffin-Manson formulae extended for multiaxial stress state and for inclusion of the mean stress effect. This criterion is also applied for the accumulated damage ahead of the existing crack tip which is assumed to be related to the crack growth rate. Three cyclic plasticity models, based on the concept of combination of several yield surfaces, are employed for computing the crack growth rate of a crack plane stress panel under several cyclic loading conditions.

  12. Prediction of Bending Stiffness for Laminated CFRP and Its Application to Manufacturing of Roof Reinforcement

    Directory of Open Access Journals (Sweden)

    Jeong-Min Lee

    2014-05-01

    Full Text Available Recently, carbon fiber reinforced plastic (CFRP with high strength, stiffness, and lightweight is used widely in number of composite applications such as commercial aircraft, transportation, machinery, and sports equipment. Especially, it is necessary to apply lightweight materials to car components for reducing energy consumption and CO2 emissions. In case of car roof reinforcement manufactured using CFRP, superior strength and bending stiffness are required for the safety of drivers in the rollover accident. Mechanical properties of CFRP laminates are generally dependent on the stacking sequence. Therefore, research of stacking sequence using CFRP prepreg is required for superior bending stiffness. In this study, the 3-point bending FE-analysis for predicting the bending stiffness of CFRP roof reinforcement was carried out on three cases [0PW∘]5, [0PW°/0UD°/0-PW°]s, and [0UD∘]5. Material properties that the six independent elastic constants are E11, E22, G12, G23, G13, and ν12 used in FE-analysis were evaluated by the tensile test in 0°, 45°, and 90° directions. Through structural strength analysis of the automobile roof reinforcement fabricated using CFRP, the effect of the stacking sequence on the bending stiffness was evaluated and validated through experiments under the same conditions as the analysis.

  13. Elastic-plastic analysis using an efficient formulation of the finite element method

    International Nuclear Information System (INIS)

    Aamodt, B.; Mo, O.

    1975-01-01

    Based on the flow theory of plasticity, the von Mises or the Tresca yield criterion and the isotropic hardening law, an incremental stiffness relationship can be established for a finite element model of the elasto-plastic structure. However, instead of including all degrees of freedom and all finite elements of the total model in a nonlinear solution process, a separation of elastic and plastic parts of the structure can be carried out. Such a separation can be obtained by identifying elastic parts of the structure as 'elastic' superelements and elasto-plastic parts of the structure as 'elasto-plastic' superelements. Also, it may be of advantage to use several levels of superelements in modelling the elastic parts of the structure. For the 'elasto-plastic' superelements the specific plastic computations such as updating of the incremental stiffness matrix and subsequent reduction (i.e. static condensation of all degrees of freedom being local to the superelements) have to be carried out repeatedly during the nonlinear solution process. The solution of the nonlinear equations is performed utilizing a combination of load incrementation and equilibrium interations. The present method of analysis is demonstrated for two larger examples of elasto-plastic analysis. (Auth.)

  14. Static bending deflection and free vibration analysis of moderate thick symmetric laminated plates using multidimensional wave digital filters

    Science.gov (United States)

    Tseng, Chien-Hsun

    2018-06-01

    This paper aims to develop a multidimensional wave digital filtering network for predicting static and dynamic behaviors of composite laminate based on the FSDT. The resultant network is, thus, an integrated platform that can perform not only the free vibration but also the bending deflection of moderate thick symmetric laminated plates with low plate side-to-thickness ratios (< = 20). Safeguarded by the Courant-Friedrichs-Levy stability condition with the least restriction in terms of optimization technique, the present method offers numerically high accuracy, stability and efficiency to proceed a wide range of modulus ratios for the FSDT laminated plates. Instead of using a constant shear correction factor (SCF) with a limited numerical accuracy for the bending deflection, an optimum SCF is particularly sought by looking for a minimum ratio of change in the transverse shear energy. This way, it can predict as good results in terms of accuracy for certain cases of bending deflection. Extensive simulation results carried out for the prediction of maximum bending deflection have demonstratively proven that the present method outperforms those based on the higher-order shear deformation and layerwise plate theories. To the best of our knowledge, this is the first work that shows an optimal selection of SCF can significantly increase the accuracy of FSDT-based laminates especially compared to the higher order theory disclaiming any correction. The highest accuracy of overall solution is compared to the 3D elasticity equilibrium one.

  15. Analysis of the discontinuous Petrov-Galerkin method with optimal test functions for the Reissner-Mindlin plate bending model

    KAUST Repository

    Calo, Victor M.; Collier, Nathan; Niemi, Antti H.

    2014-01-01

    We analyze the discontinuous Petrov-Galerkin (DPG) method with optimal test functions when applied to solve the Reissner-Mindlin model of plate bending. We prove that the hybrid variational formulation underlying the DPG method is well-posed (stable

  16. Asymptotic techniques in elastic-plastic analysis of structures

    International Nuclear Information System (INIS)

    Sayir, M.

    1983-01-01

    Elastic-plastic structures can nowadays be analyzed with the powerful numerical procedures of the finite element method. Nevertheless, in many engineering applications, analytical expressions capable of predicting with sufficient accuracy the stress distributions, the extent of the plastic zones and the load displacement behaviour could be of great practical value. For simple structures and loading stages not too far from the elastic limit, such analytical expressions may be obtained by using perturbation methods and asymptotic expansions. A small dimensionless parameter epsilon is defined as the ratio of a length characterizing the extent of the narrow plastic zone, to a conveniently chosen typical dimension of the structure. Stresses and displacements are formally expanded as asymptotic series in terms of powers of epsilon. For each order of magnitude, the exact basic relations lead to a separate set of simplified differential equations which can be integrated analytically or numerically by using standard procedures. The method is very general and can be applied to several classes of plastic behaviour and of structural problems. Three examples of very simple structures are chosen in particular to illustrate the applicability of the perturbation method to engineering problems. (orig./RW)

  17. Discrete Dislocation Plasticity Analysis of Cracks and Fracture

    NARCIS (Netherlands)

    Giessen, Erik van der; Pippan, R; Gumbsch, P

    2010-01-01

    Fracture in plastically deforming crystals involves several length scales for cleavage-like crack growth. The relevant length scales range from that of the macroscale object to the atomic scale, including the various microstructural length scales in between that are associated with, for example,

  18. Simplified non-linear time-history analysis based on the Theory of Plasticity

    DEFF Research Database (Denmark)

    Costa, Joao Domingues

    2005-01-01

    This paper aims at giving a contribution to the problem of developing simplified non-linear time-history (NLTH) analysis of structures which dynamical response is mainly governed by plastic deformations, able to provide designers with sufficiently accurate results. The method to be presented...... is based on the Theory of Plasticity. Firstly, the formulation and the computational procedure to perform time-history analysis of a rigid-plastic single degree of freedom (SDOF) system are presented. The necessary conditions for the method to incorporate pinching as well as strength degradation...

  19. Pediatric thoracic SCIWORA after back bend during dance practice: a retrospective case series and analysis of trauma mechanisms.

    Science.gov (United States)

    Ren, Jian; Zeng, Gao; Ma, Yong-Jie; Chen, Nan; Chen, Zan; Ling, Feng; Zhang, Hong-Qi

    2017-07-01

    The purpose of the study was to describe a unique type of low-energy traumatic pediatric thoracic spinal cord injury without radiographic abnormality (SCIWORA) after a back bend during dance practice and analyze the trauma mechanisms and treatment protocols. This was a retrospective case series from September 2007 to August 2016. The study was conducted at a tertiary medical center in Beijing, China (Xuanwu Hospital, China International Neuroscience Institute [China-INI], Capital Medical University). A total of 12 pediatric patients who had a clear traumatic history after back bend movements and had been diagnosed with thoracic SCIWORA were included. Clinical and imaging data were obtained for each patient. The follow-up data was analyzed. The traumatic mechanisms were investigated by analyzing the patients' medical history, spinal diffusion tensor imaging (DTI) and fiber tractography data. Of the 12 patients, 11 (91.7%) were younger than 8 years old. The mean age of the patients was 6.6 years. All patients had a clear traumatic history of severe thoracic spinal cord injury after performing back bend movements. The mean follow-up time was 36.5 months. During the follow-up period, 1 patient (8.3%) recovered completely, and 11 patients (91.7%) had unfavorable prognoses, including 4 (33.3%) with incomplete recovery and 7 (58.3%) with no change. Two patients underwent spinal DTI, which showed rupture of the nerve fiber bundle in the section of the injury. Back bend movements performed during dance practice may cause pediatric thoracic SCIWORA, particularly in children younger than 8 years old. We suggest that the mechanism of primary injury is the longitudinal distraction of the thoracic spine during back bend movements, which leads to violent distraction of the spinal cord and blunt injury of nerve axons, nerve cells, and small vessels. Spinal DTI may facilitate the diagnosis and prognostic evaluation of SCIWORA.

  20. Elasto-plastic analysis using an efficient formulation of the finite element method

    International Nuclear Information System (INIS)

    Aamodt, B.; Mo, O.

    1975-01-01

    Based on the flow theory of plasticity, the von Mises or the Tresca yield criterion and the isotropic hardening law, an incremental stiffness relationship can be established for a finite element model of the elasto-plastic structure. However, instead of including all degrees of freedom and all finite elements of the total model in a nonlinear solution process, a separation of elastic and plastic parts of the structure can be carried out. Such a separation can be obtained by identifying elastic parts of the structure as 'elastic' superelements and elasto-plastic parts of the structure as 'elasto-plastic' superelements. Also, it may be of advantage to use several levels of superelements in modelling the elastic parts of the structure. The solution of the nonlinear equations is performed utilizing a combination of load incrementation and equilibrium iterations. In this connection, a comparative numerical study of the Newton-Raphson iteration scheme, the initial stress method, and modified Newton-Raphson iteration schemes is presented. The present method of analysis is demonstrated for two larger examples of elasto-plastic analysis. Firstly, an elasto-plastic analysis of a plate with a central hole and subjected to tensile forces is carried out. The results are compared with experimental values. Secondly, a three dimensional analysis of a thick plate with a central through-crack subjected to tensile forces is considered. The variation through the plate thickness of the size of the plastic zones at the crack tip is studied. The numerical examples show that the present method is a powerful and efficient tool in elasto-plastic analysis

  1. Relating plastic in the ocean to ecological harm, a review of recent progress in risk analysis

    Science.gov (United States)

    Schuyler, Q. A.; Hardesty, B. D.; Wilcox, C.; van Sebille, E.; Mallos, N. J.; Leonard, G. H.

    2016-02-01

    Plastic pollution in the ocean is emerging as a global environmental concern. Estimates suggest that we dump on the order of 8.4 million tons of plastic in the ocean each year. This plastic reaches substantial concentrations, with at sea sampling measuring densities over 580,000 items per square kilometer. However, it is difficult to relate this exposure to resulting ecological impacts. Animals dying due to plastic ingestion or entanglement may not was ahsore, and sampling at sea is expensive and infrequent. Thus demonstrating a direct relationship between plastic in the envioronment and harm to marine wildlife is challenging. Here we review current progress on risk assessment for impacts to marine wildlife from plastic pollution. The analyses we review range from expert elicitation to integrated statistical and physical models. They range widely in scope, from estimates at the individual level to who taxa analysis. Some of the analyses reach only to exposure to the pressure, whie others carry through to estimate demographic impacts and even mortality due to ingestion of or entanglement in plastic debris in the ocean. We summarize the results of these studies, and provide a roadmap for future contributions toward estimating the actual ecological impact of plastic pollution.

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

    International Nuclear Information System (INIS)

    Ohbuchi, Yoshifumi; Sakamoto, Hidetoshi; Nagatomo, Nobuaki

    2016-01-01

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

  3. Review, mapping and analysis of the agricultural plastic waste generation and consolidation in Europe.

    Science.gov (United States)

    Briassoulis, Demetres; Babou, Epifania; Hiskakis, Miltiadis; Scarascia, Giacomo; Picuno, Pietro; Guarde, Dorleta; Dejean, Cyril

    2013-12-01

    A review of agricultural plastic waste generation and consolidation in Europe is presented. A detailed geographical mapping of the agricultural plastic use and waste generation in Europe was conducted focusing on areas of high concentration of agricultural plastics. Quantitative data and analysis of the agricultural plastic waste generation by category, geographical distribution and compositional range, and physical characteristics of the agricultural plastic waste per use and the temporal distribution of the waste generation are presented. Data were collected and cross-checked from a variety of sources, including European, national and regional services and organizations, local agronomists, retailers and farmers, importers and converters. Missing data were estimated indirectly based on the recorded cultivated areas and the characteristics of the agricultural plastics commonly used in the particular regions. The temporal distribution, the composition and physical characteristics of the agricultural plastic waste streams were mapped by category and by application. This study represents the first systematic effort to map and analyse agricultural plastic waste generation and consolidation in Europe.

  4. The creep bending of short radius pipe bends

    International Nuclear Information System (INIS)

    Spence, John

    1975-01-01

    In existing and proposed liquid metal fast breeder reactor design the pipework has considerable importance. Parts of the LMFBR include thin walled short radius bends which are expected to operate in the creep regime. In linear elasticity it is known that the assumption of long radius bends is not too severe as far as the flexibility characteristics are concerned although some modifications are necessary for accurate determination of the stresses. No data exists for nonlinear creep. Current work is aimed at elucidating the effect of the various assumptions common to linear elastic theory in so far as they affect the creep characteristics of bends on systems. Herein an energy based analysis using a simple n power constitutive law for stationary creep is employed to derive basic design data for flexibilities and stresses which will be necessary before complete systems can be assessed for creep. The analysis shows on comparison with the long radius work that the assumption of R>r is not much more restrictive in creep than for linear elasticity. Flexibilities for short radius bends appear to be well approximated by the long radius values. Thus the attractive reference stress information already derived may be used directly to find deformations without a complete knowledge of the constitutive relationship. However, stresses are somewhat different. Fortunately the maximum deviation occurs at relatively low levels of stress, the peak stresses being in fair agreement. When n=1 the present results reduce essentially to those obtained from existing linear elastic theory

  5. Effects of off-centered cracks and restraint of induced bending caused by pressure on the crack-opening-area analysis of pipes

    International Nuclear Information System (INIS)

    Rahman, S.; Wilkowski, G.M.; Bonora, N.

    1996-01-01

    Current models for the crack-opening-area analysis of pipes with circumferential through-wall cracks are based on various idealizations or assumptions which are often necessary to simplify the mathematical formulation and numerical calculation. This paper focuses on the validity of two such assumptions that involve off-centered cracks and the restraint of induced bending caused by pressure, and quantifies their effects on the crack-opening area analysis of pipes. Finite element and/or simple estimation methods were employed to compute the center-crack-opening displacement and crack-opening shape for a through-wall-cracked pipe, considering off-centered cracks and the restraint of induced bending caused by pressure. The results of the analyses show that, for both cases, the crack-opening area can be reduced significantly. For pipes with off-centered cracks, the crack-opening area can be evaluated from analyses of symmetrically centered cracks and assuming elliptical profile. For pipes with complete restraint of the induced bending caused by pressure, the reduction in crack-opening area depends on the crack size. When the crack size is small, the restraint effects can be ignored. However, when the crack size is large, the restrained crack opening can be significantly smaller than the unrestrained crack opening, depending on the length of pipe involved; hence, it may be important for the crack-opening-area and leak-rate analyses. (orig.)

  6. Bend me, shape me

    CERN Multimedia

    2002-01-01

    A Japanese team has found a way to bend and shape silicon substrates by growing a thin layer of diamond on top. The technique has been proposed as an alternative to mechanical bending, which is currently used to make reflective lenses for X-ray systems and particle physics systems (2 paragraphs).

  7. Elastic-plastic analysis of tube expansion in tubesheets

    International Nuclear Information System (INIS)

    Kasraie, B.; O'Donnell, W.J.; Porowski, J.S.; Selz, A.

    1983-01-01

    Conditions for expansion of tubes in tubesheets are often determined by the test. The tightness of the joint and pull out force are used as criteria for evaluation of the results. For closely spaced tubes, it is also necessary to control development of the plastic regions in the ligaments surrounding the tube being expanded. High local strains may occur and excessive distortion may result if the expansion of the tube is continued beyond the admissible limits. Elastic-plastic finite element analyses are performed herein in order to establish conditions for rolling of the tubes in tubesheets of low ligament efficiency. Such penetration patterns are often required in the design of tubular reactors for catalytic processes. The model considered includes individual tube expansion in tubesheets with triangular penetration patterns. The effect of prior expansion of the neighboring tubes is also evaluated. Gap elements are used to model the initial clearance of the tube in the hole. Development of the plastic zones and distortion of the ligaments is monitored during radial expansion of the tube diameter. The residual stresses between the tube and the hole surface and the history of gap closing after removal of the expansion tool are determined. The effect of axial extension of the tube on the tube thinning is determined. Tube thinning is often used as a measure of tube expansion in manufacturing processes. For the analyzed ligament efficiency, reliable joints are obtained for a thinning range within 2% to 3%

  8. Analysis of Adipate Ester Contents in PVC Plastics

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2006-01-01

    Plasticizers are needed in flexible PVC (PolyVinylChloride) products. There is serious concern that commonly used phthalate esters may harm life reproduction systems. To avoid the problems, instead adipate di-esters (AEs) of C8 to C10 alcohols are used as higher prized alternatives; e.g. di-2......-ethylhexyl adipate or DEHA [103-23-1], also known as Adimoll® or di-octyl adipate, DOA, see Fig. 1. A widely used plasticizer in food (cling) films is DEHA, often in combination with polymers, epoxidized soya-bean oil, etcetera. DEHA also occurs in children toys. We have previously shown that the presence...... of phthalate esters in PVC can be rapidly analyzed by Fourier transform (FT-) Raman spectroscopy excited with a 1064 nm laser. Here in this project we report a similar study. The aim was to find out whether FT-Raman spectroscopy can be used to determine the presence of adipate esters (AEs) as plasticizers...

  9. Spike timing analysis in neural networks with unsupervised synaptic plasticity

    Science.gov (United States)

    Mizusaki, B. E. P.; Agnes, E. J.; Brunnet, L. G.; Erichsen, R., Jr.

    2013-01-01

    The synaptic plasticity rules that sculpt a neural network architecture are key elements to understand cortical processing, as they may explain the emergence of stable, functional activity, while avoiding runaway excitation. For an associative memory framework, they should be built in a way as to enable the network to reproduce a robust spatio-temporal trajectory in response to an external stimulus. Still, how these rules may be implemented in recurrent networks and the way they relate to their capacity of pattern recognition remains unclear. We studied the effects of three phenomenological unsupervised rules in sparsely connected recurrent networks for associative memory: spike-timing-dependent-plasticity, short-term-plasticity and an homeostatic scaling. The system stability is monitored during the learning process of the network, as the mean firing rate converges to a value determined by the homeostatic scaling. Afterwards, it is possible to measure the recovery efficiency of the activity following each initial stimulus. This is evaluated by a measure of the correlation between spike fire timings, and we analysed the full memory separation capacity and limitations of this system.

  10. Green Purchasing Behavior Analysis of Government Policy About Paid Plastic Bags

    Directory of Open Access Journals (Sweden)

    Muhammad Khoiruman

    2017-06-01

    Full Text Available This research will be conducted to know: 1 The influence of green perceived value to consumer green trust to use plastic bag after the policy of using plastic bag paid at modern retail store in Surakarta. 2 The influence of green perceived risk to consumer green trust to use plastic bag after the policy of using plastic bag paid at modern retail store in Surakarta. 3 The effect of green trust on green purchase behavior of consumers to use plastic bags after the policy of using plastic bag paid at modern retail store in Surakarta. The study was conducted in modern retail stores (Alfamart, Indomart and Superindo in Surakarta using 200 respondents who shop at the modern retail store. A model that can be used to measure green purchasing behavior in the use of paid plastic bags using four interrelated variables: green perceived value, green perceived risk, green trust and green purchasing. Data analysis using Structural Equation Model (SEM. The result of analysis and discussion showed that green perceived value have positive and significant effect to green trust, green trust has positive effect on green purchasing, but green perceived risk has no significant effect to green trust.

  11. Analysis of the discontinuous Petrov-Galerkin method with optimal test functions for the Reissner-Mindlin plate bending model

    KAUST Repository

    Calo, Victor M.

    2014-01-01

    We analyze the discontinuous Petrov-Galerkin (DPG) method with optimal test functions when applied to solve the Reissner-Mindlin model of plate bending. We prove that the hybrid variational formulation underlying the DPG method is well-posed (stable) with a thickness-dependent constant in a norm encompassing the L2-norms of the bending moment, the shear force, the transverse deflection and the rotation vector. We then construct a numerical solution scheme based on quadrilateral scalar and vector finite elements of degree p. We show that for affine meshes the discretization inherits the stability of the continuous formulation provided that the optimal test functions are approximated by polynomials of degree p+3. We prove a theoretical error estimate in terms of the mesh size h and polynomial degree p and demonstrate numerical convergence on affine as well as non-affine mesh sequences. © 2013 Elsevier Ltd. All rights reserved.

  12. Bending analysis of agglomerated carbon nanotube-reinforced beam resting on two parameters modified Vlasov model foundation

    Science.gov (United States)

    Ghorbanpour Arani, A.; Zamani, M. H.

    2018-06-01

    The present work deals with bending behavior of nanocomposite beam resting on two parameters modified Vlasov model foundation (MVMF), with consideration of agglomeration and distribution of carbon nanotubes (CNTs) in beam matrix. Equivalent fiber based on Eshelby-Mori-Tanaka approach is employed to determine influence of CNTs aggregation on elastic properties of CNT-reinforced beam. The governing equations are deduced using the principle of minimum potential energy under assumption of the Euler-Bernoulli beam theory. The MVMF required the estimation of γ parameter; to this purpose, unique iterative technique based on variational principles is utilized to compute value of the γ and subsequently fourth-order differential equation is solved analytically. Eventually, the transverse displacements and bending stresses are obtained and compared for different agglomeration parameters, various boundary conditions simultaneously and variant elastic foundation without requirement to instate values for foundation parameters.

  13. Occipital bending in schizophrenia.

    Science.gov (United States)

    Maller, Jerome J; Anderson, Rodney J; Thomson, Richard H; Daskalakis, Zafiris J; Rosenfeld, Jeffrey V; Fitzgerald, Paul B

    2017-01-01

    To investigate the prevalence of occipital bending (an occipital lobe crossing or twisting across the midline) in subjects with schizophrenia and matched healthy controls. Occipital bending prevalence was investigated in 37 patients with schizophrenia and 44 healthy controls. Ratings showed that prevalence was nearly three times higher among schizophrenia patients (13/37 [35.1%]) than in control subjects (6/44 [13.6%]). Furthermore, those with schizophrenia had greater normalized gray matter volume but less white matter volume and had larger brain-to-cranial ratio. The results suggest that occipital bending is more prevalent among schizophrenia patients than healthy subjects and that schizophrenia patients have different gray matter-white matter proportions. Although the cause and clinical ramifications of occipital bending are unclear, the results infer that occipital bending may be a marker of psychiatric illness.

  14. A review of literature for the structural assessment of mitred bends

    International Nuclear Information System (INIS)

    Wood, J.

    2008-01-01

    This paper presents a state-of-the-art review of literature available for the structural assessment of all types of mitred pipe bends. Compared with smooth bends, the volume of literature available for mitres is less extensive and its scope is not as wide. Historically, this reflects a reduced application level, as well as a less demanding range of applications, such as non-high temperature use. There is also the issue that an analysis of a mitred bend is complicated by discontinuity stresses, as well as those due to cross-section ovalisation. This fact delayed the development of non-linear analysis of mitred bends. Nevertheless, there is now a substantial body of work on mitred bends. This review tabulates and characterises all publications to date in chronological order. The details of experimental specimens are highlighted, with a view to these perhaps providing useful verification data for any future finite element analysis for example. Issues of particular interest to pipework designers are discussed, including the effects of combinations of loading, out-of-circularity, tangent pipe length and flanges. Failure characteristics and loads are discussed where relevant. Topics for further research are also noted. For example, comprehensive design curves do not exist for the elastic and plastic behaviour of all mitre types, over a practical range of geometry and loading parameters. Similarly, there is still scope for further work on the effect of combined loading, end effects and out-of-circularity. Limit, collapse and burst loads are not yet available across the entire spectrum of bends and loading parameters either. Creep and optimisation represent virgin territory as far as mitred bends are concerned and given that unforeseen vibration is a common source of high-cycle fatigue failure in pipework, there must also be scope for vibration-induced fatigue studies

  15. Experimental and FE Analysis of Exterior Plastic Components of Cars under Static and Dynamic Loading Conditions

    OpenAIRE

    Faghihi, Hassan

    2011-01-01

    This thesis is composed by an experimental part and numerical part, aimed at contributing to a better knowledge of the behavior of plastic parts under different loading conditions. The study is intended to validate a FE model for simulating exterior plastic components of car especially the A-decor and plastic clips in the context of thermal and static load analysis. From the comparison of numerical and experimental results in the terms of thermal and static deformation of the A-decor, it is c...

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

    International Nuclear Information System (INIS)

    Xiao Xuejian; Chen Ruxin

    1995-02-01

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

  17. Plastic Surgeon Expertise in Predicting Breast Reconstruction Outcomes for Patient Decision Analysis

    Directory of Open Access Journals (Sweden)

    Clement S. Sun, MS

    2013-11-01

    Conclusions: The use of individual plastic surgeon–elicited probability information is not encouraged unless the individual’s prediction skill has been evaluated. In the absence of this information, a group consensus on the probability of outcomes is preferred. Without a large evidence base for calculating probabilities, estimates assessed from a group of plastic surgeons may be acceptable for purposes of breast reconstruction decision analysis.

  18. Diffraction analysis of materials under strong plastic deformation

    International Nuclear Information System (INIS)

    Pyzalla, A.

    2001-01-01

    The applicability of X-ray diffraction in analyses of the microstructure texture and intrinsic stresses of materials under strong plastic deformation is illustrated by examples and discussed. The experimental methods and findings are supplemented by numeric calculations. It is shown how the microstructure, texture and intrinsic stresses can thus be optimized already in the production process. Analyses of changes in materials during operation of a component provide information on loads and material response to loads which can then be used for optimization of the component, e.g. by constructional modifications or selective heat treatment [de

  19. ANALYSIS OF ADIPATE ESTER CONTENTS IN POLY(VINYL CHLORIDE) PLASTICS

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Otero, Amalia Dopazo

    2006-01-01

    Fourier transform (FT-) Raman spectroscopy excited with a 1064 nm laser can be used to determine the content of plasticizers in commercial flexible poly vinyl chloride (PVC) products. Our previous study [T. Nørbygaard, R.W. Berg, Analysis of phthalate ester content in PVC plastics by means of FT......-Raman Spectroscopy, Appl. Spectrosc. 58 (4) (2004) 410–413]—on detection of the presence of phthalate esters in PVC by FT-Raman spectroscopy — is here extended to the similar case of adipate esters (AEs) in samples of soft poly vinyl chloride plastics. Spectra of a range of adipate ester plasticizers (11 AEs......) in pure form are reported. We studied if qualitative and quantitative determination of the adipate ester content would be possible based on the use of proper reference samples. It was found that AEs as a group cannot be definitively identified by their characteristic Raman bands because other aliphatic...

  20. Elasto/visco-plastic analysis of moderately thick shells of revolution

    International Nuclear Information System (INIS)

    Takezono, S.; Tanoue, M.

    1981-01-01

    The analytical formulation on the elasto-visco-plastic problems of general, moderately thick shells of revolution subjected to axisymmetrical load is developed by extension of the Reissner theory in elastic shells where a consideration on the effect of shear deformations is given. The authors employ as constitutive relation of the shell materials Perzyna's equation where in the plastic range the viscosity of the material is considered. The criterion for yielding used in this analysis is the von Mises yield theory. The basic differential equations derived for elasto-visco-plastic problems are numerically solved by a finite difference method, and the solutions are obtained by integration of the incremental values. As a numerical example, the elasto/visco-plastic deformation of pressure vessels is analyzed, and the results are compared with those from the classical theory which neglects the effect of shear deformations. (orig.)

  1. Trajectory bending and energy spreading of charged ions in time-of-flight telescopes used for ion beam analysis

    International Nuclear Information System (INIS)

    Laitinen, Mikko; Sajavaara, Timo

    2014-01-01

    Carbon foil time pick-up detectors are widely used in pairs in ion beam applications as time-of-flight detectors. These detectors are suitable for a wide energy range and for all ions but at the lowest energies the tandem effect limits the achievable time of flight and therefore the energy resolution. Tandem effect occurs when an ion passes the first carbon foil of the timing detector and its charge state is changed. As the carbon foil of the first timing detector has often a non-zero voltage the ion can accelerate or decelerate before and after the timing detector. The combination of different charge state properties before and after the carbon foil now induces spread to the measured times of flight. We have simulated different time pick-up detector orientations, voltages, ions and ion energies to examine the tandem effect in detail and found out that the individual timing detector orientation and the average ion charge state have a very small influence to the magnitude of the tandem effect. On the other hand, the width of the charge state distribution for particular ion and energy in the first carbon foil, and the carbon foil voltage contributes linearly to the magnitude of the tandem effect. In the simulations low energy light ion trajectories were observed to bend in the electric fields of the first timing gate, and the magnitude of this bending was studied. It was found out that 50–150 keV proton trajectories can even bend outside the second timing gate

  2. Elasto/visco-plastic analysis of orthotropic moderately thick shells of revolution under asymmetrical loading

    International Nuclear Information System (INIS)

    Tao, K.; Takezono, S.

    1989-01-01

    An analytical method for the elasto/visco-plastic problems of general, orthotropic moderately thick shells of revolution subjected to asymmetrical loads is developed in consideration of the effect of shear deformations. The Reissner-Naghdi theory for elastic moderately thick shells is extended in this analysis. As the constitutive equation, Hooke's law for orthotropic materials is used in the elastic region, and equations based on the orthotropic visco-plastic theory derived from the orthotropic plastic theory by Hill are employed in the plastic range. The visco-plastic strain rates are related to the stresses by Perzyna's equation. The fundamental equations for the increment are numerically solved by a finite difference method and the solutions are obtained by summation of the incremental values. In order to check the adequacy of the numerical analysis, experiments are performed on the elasto/visco-plastic deformation of a titanium cylindrical shell subjected to locally distributed loads. Good agreement is obtained between the experimental results and analytical solutions

  3. Elasto/visco-plastic analysis of orthotropic moderately thick shells of revolution

    International Nuclear Information System (INIS)

    Takezono, S.; Tao, K.

    1985-01-01

    This paper describes an analytical formulation and a numerical analysis on the elasto/visco-plastic problems of orthotropic moderately thick shells of revolution under axi-symmetrical loads with applications to a cylindrical shell, and with comparison to experimental results. The analytical formulation is developed by extension of the Reissner-Naghdi theory in elastic shells where a consideration on the effect of shear deformation is given. As the constitutive equation, Hooke's law for orthotropic materials is used in the elastic range, and equations based on the orthotropic visco-plastic theory derived from the orthotropic plastic theory by Hill are employed in the plastic range. The visco-plastic strain rates are related to the stresses by Perzyna's equation. In order to check up the adequacy of the numerical analysis, experiments on elasto/visco-plastic deformation of a titanium cylindrical shell subject to internal axi-symmetrical loads are performed. Good agreement is obtained between experimental results and analytical solution. (orig.)

  4. Characterization and study of photonic crystal fibres with bends

    International Nuclear Information System (INIS)

    Belhadj, W.; AbdelMalek, F.; Bouchriha, H.

    2006-01-01

    Analysis of a photonic crystal fibre (PRCF) with bends is presented. Using the versatile finite difference time domain method, the modal characteristics of the PCFs are found. Possibilities of employing PCFs with bends in sensing are discussed. It is found that a large evanescent field is present when the bend angle exceeds 45 o

  5. Effects of off-centered crack and restraint of induced bending due to pressure on the crack-opening-area analysis of pipes

    International Nuclear Information System (INIS)

    Rahman, S.; Ghadiali, N.; Wilkowski, G.; Bonora, N.

    1995-01-01

    Estimation of leak rate is an important element in developing leak-before-break (LBB) methodology for piping integrity and safety analysis of nuclear power plants. Here, current models for the crack-opening-area analysis of pipes with circumferential through-wall cracks are based on various idealizations or assumption which are often necessary to simplify the mathematical formulation and numerical calculation. This paper focuses on the validity of two such assumptions involving off-centered cracks and restraint of induced bending due to pressure and quantifies their effects on the crack-opening analysis of pipes. Both finite element and/or simple estimation methods were employed to compute the center-crack-opening displacement and crack-opening shape for a through-wall-cracked pipe considering off-centered cracks and restrain of induced bending due to pressure. The results of analyses show that for both cases the crack-opening area can be reduced significantly. For pipes with off-centered cracks, the crack-opening area can be evaluated from analyses of symmetrically centered cracks and assuming elliptical profile. For pipes with complete restraint of induced bending due to pressure, the reduction of crack-opening area depends on the crack size. When the crack size is small, the restraint effects can be ignored. However, when the crack size is larger, the restrained crack-opening can be significantly smaller than the unrestrained crack-opening depending on the length of pipe involved, and hence, may be important for the crack-opening-area and leak-rate analyses

  6. Study of Selected Composites Copper Concentrate-Plastic Waste Using Thermal Analysis

    Science.gov (United States)

    Szyszka, Danuta

    2017-12-01

    The paper presents thermal analysis of selected composites (copper concentrate, plastic waste) in two stages. The first stage consisted in thermogravimetric analysis and differential thermal analysis on the applied plastic waste and copper concentrate, and subsequently, a comparative study has been carried out on products obtained, constituting composites of those materials. As a result of analyses, it was found that up to ca. 400 °C composites show high thermal stability, whereas above that temperature, a thermal decomposition of the composite occurs, resulting in emissions of organic compounds, i.e. hydrocarbon compounds and organic oxygenate derivatives.

  7. Failure analysis of leakage current in plastic encapsulated packages

    International Nuclear Information System (INIS)

    Hu, S.J.; Cheang, F.T.

    1989-12-01

    Plastic encapsulated packages exhibit high leakage current after a few hundred hours steam pressure pot test. The present study investigates two possible sources of leakage current, the mold compound and the lead frame tape used for taping the lead frame fingers. The results of the study indicate that the leakage current is independent of the frame and is not caused by the mold compound. The data further indicates that it is the ionic contents and acrylic-based adhesive layer of the lead frame tapes which cause the leakage current. To eliminate the leakage current, lead frame tape with low ionic contents and non acrylic-based adhesive should be used. (author). 1 fig., 2 tabs, 3 graphs

  8. J-integral and limit load analysis of semi-elliptical surface cracks in plates under bending

    International Nuclear Information System (INIS)

    Lei, Y.

    2004-01-01

    Systematic detailed linear and non-linear finite element (FE) analyses are performed for semi-elliptical surface cracks in plates under bending. Limit load (moment) solutions are obtained from the FE J results via the reference stress method. The FE results show that the Newman and Raju stress intensity factor equation is reasonably accurate and the Yagawa et al. J solution may significantly under estimate J for bending load. The relationship between J and the limit load is found to be dependent on the ratio a/t and a/c, where a and c are the depth and the half-length of the crack and t is the plate thickness. For a/t≤0.5 with a/c=0.2, J for any position along a crack front can be predicted by the reference stress method using a single limit load value except for the points very close to the plate surface. For all other cases, it can only be approximately estimated by the reference stress method because a limit load value that can satisfy all the FE J solutions along the crack front cannot be found. However, for all the cases examined, the maximum J along the crack front can be well predicted by the reference stress method when a proper global limit load is used. The Goodall and Webster global limit load equation is extended to any crack depth. The limit load data obtained in this paper can be well reproduced by the extended equation

  9. Experimental Analysis of Repaired Masonry Elements with Flax-FRCM and PBO-FRCM Composites Subjected to Axial Bending Loads

    Directory of Open Access Journals (Sweden)

    Oscar A. Cevallos

    2015-11-01

    Full Text Available In the construction industry, the use of natural fabrics as a reinforcement for cement-based composites has shown great potential. The use of these sustainable composites to provide strengthening or repair old masonry structures that exhibit structural problems mainly due to a poor tensile strength of the mortar/brick joints is revealed to be a promising area of research. One of the most significant load conditions affecting the mechanical response of masonry structures occurs when axial bending loads are applied on the resistant cross-section. In this study, three different types of masonry elements were built using clay bricks and a lime-based mortar. After 28 days, the samples were subjected to concentric and eccentric compressive loads. In order to produce significant bending effects, the compressive loads were applied with large eccentricity, and a sudden failure characterized the behavior of the unreinforced masonry (URM elements. The tested masonry specimens were repaired using fabric-reinforced cementitious matrix (FRCM composites produced using bi-directional flax and polyparaphenylene benzobisoxazole (PBO fabrics. The mechanical behavior of the URM and repaired samples was compared in terms of load-displacement and moment-curvature responses. Furthermore, the results achieved using flax-FRCM composites were compared with those of using PBO-FRCM composites.

  10. Residual Stress Analysis of Severe Plastic Deformed Materials using the Finite Element Method and the Neutron Diffraction Method

    International Nuclear Information System (INIS)

    Kang, Mi Hyun; Seong, Back Suck; Kim, Hyoung Seop

    2009-01-01

    Severe plastic deformation (SPD) is one of the most promising top-down techniques, moving towards industrialization to fabricate bulk ultrafine grain materials. The strain distribution and deformation behavior during the ECAP (equal channel angular pressing), influenced by tool angles, friction and material behavior, was studied through experimental and numerical analyses. The residual stress of work piece which was straight before ECAP produces many serious problems in the next processing e.g. input of the work piece for the next ECAP. The bent work piece needs additional straightening or surface polishing even if the amount of bending is small, and residual stress need to be released before service applications. Residual stress, particularly tensile residual stress can be a very important factor in affecting the reliability and integrity of working parts. The formation of tensile residual stress may result in initiation of fatigue cracks, stress corrosion cracking, or other types of fracture. Hence, residual stress and resulting bending need to be controlled during ECAP. Thus, in current study the bending behavior and the residual stress of the work piece in ECAP are analyzed through experimental and finite element analyses by considering the effects of material, geometric, and processing parameters individually. The stress states in the ECAP processed work piece were measured by the non-destructive way using neutron diffraction. Efforts were made to suggest the alternate routes to reduce the residual stress and bending of work piece in ECAP

  11. Calculation of elastic-plastic strain ranges for fatigue analysis based on linear elastic stresses

    International Nuclear Information System (INIS)

    Sauer, G.

    1998-01-01

    Fatigue analysis requires that the maximum strain ranges be known. These strain ranges are generally computed from linear elastic analysis. The elastic strain ranges are enhanced by a factor K e to obtain the total elastic-plastic strain range. The reliability of the fatigue analysis depends on the quality of this factor. Formulae for calculating the K e factor are proposed. A beam is introduced as a computational model for determining the elastic-plastic strains. The beam is loaded by the elastic stresses of the real structure. The elastic-plastic strains of the beam are compared with the beam's elastic strains. This comparison furnishes explicit expressions for the K e factor. The K e factor is tested by means of seven examples. (orig.)

  12. Analysis of Elastic-Plastic J Integrals for 3-Dimensional Cracks Using Finite Element Alternating Method

    International Nuclear Information System (INIS)

    Park, Jai Hak

    2009-01-01

    SGBEM(Symmetric Galerkin Boundary Element Method)-FEM alternating method has been proposed by Nikishkov, Park and Atluri. In the proposed method, arbitrarily shaped three-dimensional crack problems can be solved by alternating between the crack solution in an infinite body and the finite element solution without a crack. In the previous study, the SGBEM-FEM alternating method was extended further in order to solve elastic-plastic crack problems and to obtain elastic-plastic stress fields. For the elastic-plastic analysis the algorithm developed by Nikishkov et al. is used after modification. In the algorithm, the initial stress method is used to obtain elastic-plastic stress and strain fields. In this paper, elastic-plastic J integrals for three-dimensional cracks are obtained using the method. For that purpose, accurate values of displacement gradients and stresses are necessary on an integration path. In order to improve the accuracy of stress near crack surfaces, coordinate transformation and partitioning of integration domain are used. The coordinate transformation produces a transformation Jacobian, which cancels the singularity of the integrand. Using the developed program, simple three-dimensional crack problems are solved and elastic and elastic-plastic J integrals are obtained. The obtained J integrals are compared with the values obtained using a handbook solution. It is noted that J integrals obtained from the alternating method are close to the values from the handbook

  13. Analysis of ionospheric structure influences on residual ionospheric errors in GNSS radio occultation bending angles based on ray tracing simulations

    Science.gov (United States)

    Liu, Congliang; Kirchengast, Gottfried; Sun, Yueqiang; Zhang, Kefei; Norman, Robert; Schwaerz, Marc; Bai, Weihua; Du, Qifei; Li, Ying

    2018-04-01

    The Global Navigation Satellite System (GNSS) radio occultation (RO) technique is widely used to observe the atmosphere for applications such as numerical weather prediction and global climate monitoring. The ionosphere is a major error source to RO at upper stratospheric altitudes, and a linear dual-frequency bending angle correction is commonly used to remove the first-order ionospheric effect. However, the higher-order residual ionospheric error (RIE) can still be significant, so it needs to be further mitigated for high-accuracy applications, especially from 35 km altitude upward, where the RIE is most relevant compared to the decreasing magnitude of the atmospheric bending angle. In a previous study we quantified RIEs using an ensemble of about 700 quasi-realistic end-to-end simulated RO events, finding typical RIEs at the 0.1 to 0.5 µrad noise level, but were left with 26 exceptional events with anomalous RIEs at the 1 to 10 µrad level that remained unexplained. In this study, we focused on investigating the causes of the high RIE of these exceptional events, employing detailed along-ray-path analyses of atmospheric and ionospheric refractivities, impact parameter changes, and bending angles and RIEs under asymmetric and symmetric ionospheric structures. We found that the main causes of the high RIEs are a combination of physics-based effects - where asymmetric ionospheric conditions play the primary role, more than the ionization level driven by solar activity - and technical ray tracer effects due to occasions of imperfect smoothness in ionospheric refractivity model derivatives. We also found that along-ray impact parameter variations of more than 10 to 20 m are possible due to ionospheric asymmetries and, depending on prevailing horizontal refractivity gradients, are positive or negative relative to the initial impact parameter at the GNSS transmitter. Furthermore, mesospheric RIEs are found generally higher than upper-stratospheric ones, likely due to

  14. Application of FRET probes in the analysis of neuronal plasticity

    Directory of Open Access Journals (Sweden)

    Yoshibumi eUeda

    2013-10-01

    Full Text Available Breakthroughs in imaging techniques and optical probes in recent years have revolutionized the field of life sciences in ways that traditional methods could never match. The spatial and temporal regulation of molecular events can now be studied with great precision. There have been several key discoveries that have made this possible. Since GFP was cloned in 1992, it has become the dominant tracer of proteins in living cells. Then the evolution of color variants of GFP opened the door to the application of Förster resonance energy transfer (FRET, which is now widely recognized as a powerful tool to study complicated signal transduction events and interactions between molecules. Employment of fluorescent lifetime imaging microscopy (FLIM allows the precise detection of FRET in small subcellular structures such as dendritic spines. In this review, we provide an overview of the basic and practical aspects of FRET imaging and discuss how different FRET probes have revealed insights into the molecular mechanisms of synaptic plasticity and enabled visualization of neuronal network activity both in vitro and in vivo.

  15. Application of neutron activation analysis in discovering plastic explosive

    Directory of Open Access Journals (Sweden)

    S. H. M.

    2000-06-01

    Full Text Available   In this work, the ability of neuron probes to detect to plastic bombs in airway luggage or postal parcels has been investigated. As explosives are rich in nitrogen, 10.83 MeV gamma radiations may be employed to detect this nitrogen. First, the method is studied theoretically by using the Monte-Carlo simulation method and the MCNP code. The optimum distance, the positions of the detector and the sample, and the optimum moderator thickness are determined by considering the important pile-up effect.   Second, by using the model obtained from the data, the Am-Be neuron source is deployed experimentally. In practice, given the role of the source and the pile up effect, the optimum conditions found by calculations are changed and the primary plan is revised, according to experimental results.   Finally, the potential of this method is tested by analyzing the results which are obtained for the two kinds of moderators, paraffin and graphite. The data are then reviewed from different perspectives, and different effect on the response of the detectors.

  16. Theoretical basis for a transient thermal elastic-plastic stress analysis of nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Hsu, T.R.; Bertels, A.W.M.; Banerjee, S.; Harrison, W.C.

    1976-07-01

    This report presents the theoretical basis for a transient thermal elastic-plastic stress analysis of a nuclear reactor fuel element subject to severe transient thermo-mechanical loading. A finite element formulation is used for both the non-linear stress analysis and thermal analysis. These two major components are linked together to form an integrated program capable of predicting fuel element transient behaviour in two dimensions. Specific case studies are presented to illustrate capabilities of the analysis. (author)

  17. Analysis of the effect of volume on the bending strength of the Spanish scot and laricio pine timber

    Directory of Open Access Journals (Sweden)

    Fernández-Golfín, J. I.

    2002-12-01

    Full Text Available Since the beginning of the XX century it has been recognized that the bending strength of timber is affected by the size of the specimen. In the present work the influence of depth (h and thickness (t on the characteristic bending strength (fk of both Scot (Pinus sylvestris and Laricio (Pinus nigra pine Spanish grown timber is assessed. 1.733 pieces of both species ranging in size from 100x40x2500 mm to 200x70x4.500 mm and especially sampled for this work, have been tested for bending in accordance with UNE EN 408 standard. In both species, the influence of depth and thickness on the characteristic bending strength of timber is highly significative but different between them and lead to conclude that the effect of the species is also significative and thus that the proposition of general values should be done cautiously, avoiding extrapolations. It is also concluded that, for both species, the effect of thickness seems to be highly significative and thus shouldn’t be ignored by the European standards. Finally, the convenience of revising the present depth factor considered in UNE EN 384 and UNE ENV 1995-1-1 standards is also suggested.

    Desde principios del siglo XX se conoce que la resistencia a la flexión de un elemento estructural viene afectada por su volumen. En el presente trabajo se analiza la influencia de la altura (h y del espesor (t de la sección de la pieza en la resistencia característica a flexión (fk de la madera de pino silvestre (Pinus sylvestris y pino laricio (Pinus nigra de procedencia española. 1.733 vigas de tamaño variable entre 100x40x2500 mm y 200x70x4.500 mm, muestreadas especialmente para este trabajo, fueron ensayadas flexión de acuerdo con la norma UNE EN 408. La influencia de la altura de la sección y del espesor sobre la resistencia característica a flexión en ambas especies de madera resulta ser significativa aunque distinta entre ellas, lo que lleva a concluir que

  18. Three dimensional vibration and bending analysis of carbon nanotubes embedded in elastic medium based on theory of elasticity

    Directory of Open Access Journals (Sweden)

    M. Shaban

    Full Text Available This paper studies free vibration and bending behavior of singlewalled carbon nanotubes (SWCNTs embedded on elastic medium based on three-dimensional theory of elasticity. To accounting the size effect of carbon nanotubes, non-local theory is adopted to shell model. The nonlocal parameter is incorporated into all constitutive equations in three dimensions. The surrounding medium is modeled as two-parameter elastic foundation. By using Fourier series expansion in axial and circumferential direction, the set of coupled governing equations are reduced to the ordinary differential equations in thickness direction. Then, the state-space method as an efficient and accurate method is used to solve the resulting equations analytically. Comprehensive parametric studies are carried out to show the influences of the nonlocal parameter, radial and shear elastic stiffness, thickness-to-radius ratio and radiusto-length ratio.

  19. Post analysis of AE data of seal plug leakage of NAPS-2 and fatigue crack initiation of three point bend sample using cluster and artificial neural network

    International Nuclear Information System (INIS)

    Singh, A.K.; Mehta, H.R.; Bhattacharya, S.

    2003-01-01

    Acoustic Emission data is very weak and passive in nature that leads to a challenging task to separate AE data from noise. This paper illuminates the work done of post analysis of acoustic emission data of seal plug leakage of operating PHWR, NAPS-2, Narora and Fatigue Crack initiation of three-point bend sample using cluster analysis and artificial neural network (ANN). First the known AE data generated in lab by PCB debonding and pencil leak break were analyzed using ANN to get the confidence. After that the AE data acquired by scanning all 306-coolant channels at NAPS-2 was sorted out in five separate clusters for different leakage rate and background noise. Fatigue crack initiation, AE data generated in MSD lab on three-point bend sample was clustered in ten separate clusters in which one cluster was having 98% AE data of crack initiation period noted with the help of travelling microscope but remaining clusters indicating AE data of different sources and noise. The above data was further analysed with self organizing map of Artificial Neural Network. (author)

  20. Adjustable Tooling for Bending Brake

    Science.gov (United States)

    Ellis, J. M.

    1986-01-01

    Deep metal boxes and other parts easily fabricated. Adjustable tooling jig for bending brake accommodates spacing blocks and either standard male press-brake die or bar die. Holds spacer blocks, press-brake die, bar window die, or combination of three. Typical bending operations include bending of cut metal sheet into box and bending of metal strip into bracket with multiple inward 90 degree bends. By increasing free space available for bending sheet-metal parts jig makes it easier to fabricate such items as deep metal boxes or brackets with right-angle bends.

  1. Rational analysis and index of plasticity of clays for extrusion evaluation

    International Nuclear Information System (INIS)

    Silva, A.R.; Guimaraes Filho, M.A.S.; Santos, C.V.P.; Fagury Neto, E.; Rabelo, A.A.

    2011-01-01

    In the microregion Maraba, in the southeast paraense, there's a important industrial park in the area of red ceramic due to the quality of the extracted clays in the proximities of their rivers. With the intention of collaborating for the production of tiles and structural blocks of quality, in this work the rational analysis of clays was accomplished, through the relationship of the qualitative X-ray diffraction and X-ray fluorescence results. Was possible to quantify the present phases in the collected clays and these results were correlated to the Atterberg's limits - plasticity and liquidity limitsand the respective plasticity indexes - making possible to classify the clays in areas of great and acceptable extrusion. The results of the rational analysis demonstrated that the analyzed clays are plastic kaolinites and don't present quantitative differences very accentuated among the present phases detected besides they possess an area of acceptable extrusion naturally. (author)

  2. Application of generalized function to dynamic analysis of elasto-plastic thick plates

    International Nuclear Information System (INIS)

    Zheng, D.; Weng, Z.

    1987-01-01

    The elasto-plastic dynamic analysis of thick plates is of great significance to the research and the design on an anti-seismic structure and an anti-explosive structure. In this paper, the derivative of δ-function is handled by using the generalized function. The dynamic influence coefficient of thick plates in deduced. A dynamic response of elasto-plastic thick plates its material has hardening behaviour considered, is analysed by using known elastic solutions. The general expressions for the dynamic response of elasto-plastic rectangular thick plates subjected arbitrary loads are given. Detailed computations are performed for the square plates of various height-span ratios. The results are compared with those obtained from the improved theory and the classical theory of plates. The modification of the classical deflection theory for plates is employed. The increment analysis is used for calculations. The yield function is considered as a function of inplane and transverse shear stresses. (orig./GL)

  3. Elastic-plastic analysis of the toroidal field coil inner leg of the compact ignition tokamak

    International Nuclear Information System (INIS)

    Horie, T.

    1987-07-01

    Elastic-plastic analyses were made for the inner leg of the Compact Ignition Tokamak toroidal field (TF) coil, which is made of copper-Inconel composite material. From the result of the elastic-plastic analysis, the effective Young's moduli of the inner leg were determined by the analytical equations. These Young's moduli are useful for the three-dimensional, elastic, overall TF coil analysis. Comparison among the results of the baseline design (R = 1.324 m), the bucked pressless design, the 1.527-m major radius design, and the 1.6-m major radius design was also made, based on the elastic-plastic TF coil inner leg analyses

  4. Simplified method for elastic plastic analysis of material presenting bilinear kinematic hardening

    International Nuclear Information System (INIS)

    Roche, R.

    1983-12-01

    A simplified method for elastic plastic analysis is presented. Material behavior is assumed to be elastic plastic with bilinear kinematic hardening. The proposed method give a strain-stress field fullfilling material constitutive equations, equations of equilibrium and continuity conditions. This strain-stress is obtained through two linear computations. The first one is the conventional elastic analysis of the body submitted to the applied load. The second one use tangent matrix (tangent Young's modulus and Poisson's ratio) for the determination of an additional stress due to imposed initial strain. Such a method suits finite elements computer codes, the most useful result being plastic strains resulting from the applied loading (load control or deformation control). Obviously, there is not unique solution, for stress-strain field is not depending only of the applied load, but of the load history. Therefore, less pessimistic solutions can be got by one or two additional linear computations [fr

  5. Rapid discrimination of plastic packaging materials using MIR spectroscopy coupled with independent components analysis (ICA)

    Energy Technology Data Exchange (ETDEWEB)

    Kassouf, Amine, E-mail: amine.kassouf@agroparistech.fr [ER004 “Lebanese Food Packaging”, Faculty of Sciences II, Lebanese University, 90656 Jdeideth El Matn, Fanar (Lebanon); INRA, UMR1145 Ingénierie Procédés Aliments, 1 Avenue des Olympiades, 91300 Massy (France); AgroParisTech, UMR1145 Ingénierie Procédés Aliments, 16 rue Claude Bernard, 75005 Paris (France); Maalouly, Jacqueline, E-mail: j_maalouly@hotmail.com [ER004 “Lebanese Food Packaging”, Faculty of Sciences II, Lebanese University, 90656 Jdeideth El Matn, Fanar (Lebanon); Rutledge, Douglas N., E-mail: douglas.rutledge@agroparistech.fr [INRA, UMR1145 Ingénierie Procédés Aliments, 1 Avenue des Olympiades, 91300 Massy (France); AgroParisTech, UMR1145 Ingénierie Procédés Aliments, 16 rue Claude Bernard, 75005 Paris (France); Chebib, Hanna, E-mail: hchebib@hotmail.com [ER004 “Lebanese Food Packaging”, Faculty of Sciences II, Lebanese University, 90656 Jdeideth El Matn, Fanar (Lebanon); Ducruet, Violette, E-mail: violette.ducruet@agroparistech.fr [INRA, UMR1145 Ingénierie Procédés Aliments, 1 Avenue des Olympiades, 91300 Massy (France); AgroParisTech, UMR1145 Ingénierie Procédés Aliments, 16 rue Claude Bernard, 75005 Paris (France)

    2014-11-15

    Highlights: • An innovative technique, MIR-ICA, was applied to plastic packaging separation. • This study was carried out on PE, PP, PS, PET and PLA plastic packaging materials. • ICA was applied to discriminate plastics and 100% separation rates were obtained. • Analyses performed on two spectrometers proved the reproducibility of the method. • MIR-ICA is a simple and fast technique allowing plastic identification/classification. - Abstract: Plastic packaging wastes increased considerably in recent decades, raising a major and serious public concern on political, economical and environmental levels. Dealing with this kind of problems is generally done by landfilling and energy recovery. However, these two methods are becoming more and more expensive, hazardous to the public health and the environment. Therefore, recycling is gaining worldwide consideration as a solution to decrease the growing volume of plastic packaging wastes and simultaneously reduce the consumption of oil required to produce virgin resin. Nevertheless, a major shortage is encountered in recycling which is related to the sorting of plastic wastes. In this paper, a feasibility study was performed in order to test the potential of an innovative approach combining mid infrared (MIR) spectroscopy with independent components analysis (ICA), as a simple and fast approach which could achieve high separation rates. This approach (MIR-ICA) gave 100% discrimination rates in the separation of all studied plastics: polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS) and polylactide (PLA). In addition, some more specific discriminations were obtained separating plastic materials belonging to the same polymer family e.g. high density polyethylene (HDPE) from low density polyethylene (LDPE). High discrimination rates were obtained despite the heterogeneity among samples especially differences in colors, thicknesses and surface textures. The reproducibility of

  6. Rapid discrimination of plastic packaging materials using MIR spectroscopy coupled with independent components analysis (ICA)

    International Nuclear Information System (INIS)

    Kassouf, Amine; Maalouly, Jacqueline; Rutledge, Douglas N.; Chebib, Hanna; Ducruet, Violette

    2014-01-01

    Highlights: • An innovative technique, MIR-ICA, was applied to plastic packaging separation. • This study was carried out on PE, PP, PS, PET and PLA plastic packaging materials. • ICA was applied to discriminate plastics and 100% separation rates were obtained. • Analyses performed on two spectrometers proved the reproducibility of the method. • MIR-ICA is a simple and fast technique allowing plastic identification/classification. - Abstract: Plastic packaging wastes increased considerably in recent decades, raising a major and serious public concern on political, economical and environmental levels. Dealing with this kind of problems is generally done by landfilling and energy recovery. However, these two methods are becoming more and more expensive, hazardous to the public health and the environment. Therefore, recycling is gaining worldwide consideration as a solution to decrease the growing volume of plastic packaging wastes and simultaneously reduce the consumption of oil required to produce virgin resin. Nevertheless, a major shortage is encountered in recycling which is related to the sorting of plastic wastes. In this paper, a feasibility study was performed in order to test the potential of an innovative approach combining mid infrared (MIR) spectroscopy with independent components analysis (ICA), as a simple and fast approach which could achieve high separation rates. This approach (MIR-ICA) gave 100% discrimination rates in the separation of all studied plastics: polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS) and polylactide (PLA). In addition, some more specific discriminations were obtained separating plastic materials belonging to the same polymer family e.g. high density polyethylene (HDPE) from low density polyethylene (LDPE). High discrimination rates were obtained despite the heterogeneity among samples especially differences in colors, thicknesses and surface textures. The reproducibility of

  7. An analysis of heat field of metal sheet during elastic-plastic deformation

    International Nuclear Information System (INIS)

    Li, S.X.; Huang, Y.; Shih, C.H.

    1985-08-01

    This paper describes the application of the finite element analysis to calculate the temperature distribution generated during the process of elastic-plastic deformation. A better agreement is found between the results of heat field computed by use of the finite element analysis and that measured by use of an infrared camera. The results indicate that the method of finite element analysis used for heat field evaluation is reliable. (author)

  8. A critical analysis of the biological impacts of plasticizers on wildlife

    DEFF Research Database (Denmark)

    Oehlmann, J.; Schulte-Oehlmann, U.; Kloas, W.

    2009-01-01

    This review provides a critical analysis of the biological effects of the most widely used plasticizers, including dibutyl phthalate, diethylhexyl phthalate, dimethyl phthalate, butyl benzyl phthalate and bisphenol A (BPA), on wildlife, with a focus on annelids ( both aquatic and terrestrial...

  9. Laboratory and exterior decay of wood plastic composite boards: voids analysis and computed tomography

    Science.gov (United States)

    Grace Sun; Rebecca E. Ibach; Meghan Faillace; Marek Gnatowski; Jessie A. Glaeser; John Haight

    2016-01-01

    After exposure in the field and laboratory soil block culture testing, the void content of wood–plastic composite (WPC) decking boards was compared to unexposed samples. A void volume analysis was conducted based on calculations of sample density and from micro-computed tomography (microCT) data. It was found that reference WPC contains voids of different sizes from...

  10. A unified approach to the analysis and design of elasto-plastic structures with mechanical contact

    Science.gov (United States)

    Bendsoe, Martin P.; Olhoff, Niels; Taylor, John E.

    1990-01-01

    With structural design in mind, a new unified variational model has been developed which represents the mechanics of deformation elasto-plasticity with unilateral contact conditions. For a design problem formulated as maximization of the load carrying capacity of a structure under certain constraints, the unified model allows for a simultaneous analysis and design synthesis for a whole range of mechanical behavior.

  11. Evaluation of a disposable plastic Neubauer counting chamber for semen analysis.

    Science.gov (United States)

    Kirkman-Brown, Jackson; Björndahl, Lars

    2009-02-01

    To evaluate whether disposable plastic counting chambers effectively could replace nondisposable, time-consuming, and potentially dangerous glass hemocytometers. Evaluation of equipment in modern laboratory andrology. Comparison of results obtained with plastic chambers with results obtained with "gold-standard" glass hemocytometer counts. Diagnostic laboratory for andrology. Twenty-one patients undergoing investigation for infertility problems. No interventions with patients; sperm in diluted semen samples were used when patients had allowed the use for research and training. Sperm concentration, difference from results obtained with standard equipment. In the first three experimental series, with use of standard routine phase-contrast microscopy, significantly lower count results were obtained consistently from the plastic chambers than from standard chambers. In the fourth series, with use of specialized equipment, equivalent results were obtained but with a considerably greater time commitment because of difficulties in distinguishing sperm adjacent to the gridlines in the plastic chambers. The plastic disposable chamber type was not suitable for routine semen analysis because results are variable depending on the microscope used, and increased time is necessary to do the assessment accurately.

  12. Mathematical and numerical analysis of hyper-elastic systems and introduction of plasticity

    International Nuclear Information System (INIS)

    Kluth, G.

    2008-12-01

    The goal is to model mathematically and numerically the dynamic phenomenons for solids in finite plasticity. We suggest a model that we call hyper-elasto-plastic based on hyper-elastic systems of conservation laws and on the use of an equation of state that we have constructed so as to achieve the plastic yield criterion of Von Mises. This model gives exact (analytic) solutions with shock split to flyer-plate experiments. The mathematical analysis of this model is done (hyperbolicity, characteristic fields, involutions and entropy). In the numerical part, we give 1D and 2D Lagrangian schemes which satisfy an entropy criterion. Moreover, thanks to a special discretization of the equations on deformation gradient, we satisfy some discrete involutions. In this work, the degeneracy of the solid model into hydrodynamic models is studied at the continuous level, and achieved at the numerical one. On different problems, we show the validity of our model and our numerical schemes. (author)

  13. Finite element analysis of plastic recycling machine designed for ...

    African Journals Online (AJOL)

    ... design was evaluated using finite element analysis (FEA) tool in Solid Works Computer ... Also, a minimum factor of safety value of 5.3 was obtained for shredder shaft ... Machine; Design; Recycling; Sustainability; Finite Element; Simulation ...

  14. Theoretical analysis of the background intensity distribution in X-ray Birefringence Imaging using synchrotron bending-magnet radiation

    Science.gov (United States)

    Sutter, John P.; Dolbnya, Igor P.; Collins, Stephen P.; Harris, Kenneth D. M.; Edwards-Gau, Gregory R.; Palmer, Benjamin A.

    2015-04-01

    In the recently developed technique of X-ray Birefringence Imaging, molecular orientational order in anisotropic materials is studied by exploiting the birefringence of linearly polarized X-rays with energy close to an absorption edge of an element in the material. In the experimental setup, a vertically deflecting high-resolution double-crystal monochromator is used upstream from the sample to select the appropriate photon energy, and a horizontally deflecting X-ray polarization analyzer, consisting of a perfect single crystal with a Bragg reflection at Bragg angle of approximately 45°, is placed downstream from the sample to measure the resulting rotation of the X-ray polarization. However, if the experiment is performed on a synchrotron bending-magnet beamline, then the elliptical polarization of the X-rays out of the electron orbit plane affects the shape of the output beam. Also, because the monochromator introduces a correlation between vertical position and photon energy to the X-ray beam, the polarization analyzer does not select the entire beam, but instead selects a diagonal stripe, the slope of which depends on the Bragg angles of the monochromator and the polarization analyzer. In the present work, the final background intensity distribution is calculated analytically because the phase space sampling methods normally used in ray traces are too inefficient for this setup. X-ray Birefringence Imaging data measured at the Diamond Light Source beamline B16 agree well with the theory developed here.

  15. Theoretical analysis of the background intensity distribution in X-ray Birefringence Imaging using synchrotron bending-magnet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sutter, John P., E-mail: john.sutter@diamond.ac.uk; Dolbnya, Igor P.; Collins, Stephen P. [Diamond Light Source Ltd., Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom); Harris, Kenneth D. M.; Edwards-Gau, Gregory R. [School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, Wales (United Kingdom); Palmer, Benjamin A. [Department of Structural Biology, Weizmann Institute of Science, 234 Herzl St., Rehovot 7610001 (Israel)

    2015-04-28

    In the recently developed technique of X-ray Birefringence Imaging, molecular orientational order in anisotropic materials is studied by exploiting the birefringence of linearly polarized X-rays with energy close to an absorption edge of an element in the material. In the experimental setup, a vertically deflecting high-resolution double-crystal monochromator is used upstream from the sample to select the appropriate photon energy, and a horizontally deflecting X-ray polarization analyzer, consisting of a perfect single crystal with a Bragg reflection at Bragg angle of approximately 45°, is placed downstream from the sample to measure the resulting rotation of the X-ray polarization. However, if the experiment is performed on a synchrotron bending-magnet beamline, then the elliptical polarization of the X-rays out of the electron orbit plane affects the shape of the output beam. Also, because the monochromator introduces a correlation between vertical position and photon energy to the X-ray beam, the polarization analyzer does not select the entire beam, but instead selects a diagonal stripe, the slope of which depends on the Bragg angles of the monochromator and the polarization analyzer. In the present work, the final background intensity distribution is calculated analytically because the phase space sampling methods normally used in ray traces are too inefficient for this setup. X-ray Birefringence Imaging data measured at the Diamond Light Source beamline B16 agree well with the theory developed here.

  16. Experimental Test of Data Analysis Methods from Staggered Pair X-ray Beam Position Monitors at Bending Magnet Beamlines

    Science.gov (United States)

    Buth, G.; Huttel, E.; Mangold, S.; Steininger, R.; Batchelor, D.; Doyle, S.; Simon, R.

    2013-03-01

    Different methods have been proposed to calculate the vertical position of the photon beam centroid from the four blade currents of staggered pair X-ray beam position monitors (XBPMs) at bending magnet beamlines since they emerged about 15 years ago. The original difference-over-sum method introduced by Peatman and Holldack is still widely used, even though it has been proven to be rather inaccurate at large beam displacements. By systematically generating bumps in the electron orbit of the ANKA storage ring and comparing synchronized data from electron BPMs and XBPM blade currents, we have been able to show that the log-ratio method by S. F. Lin, B.G. Sun et al. is superior (meaning the characteristic being closer to linear) to the ratio method, which in turn is superior to the difference over sum method. These findings are supported by simulations of the XBPM response to changes of the beam centroid. The heuristic basis for each of the methods is investigated. The implications on using XBPM readings for orbit correction are discussed

  17. Usage of information safety requirements in improving tube bending process

    Science.gov (United States)

    Livshitz, I. I.; Kunakov, E.; Lontsikh, P. A.

    2018-05-01

    This article is devoted to an improvement of the technological process's analysis with the information security requirements implementation. The aim of this research is the competition increase analysis in aircraft industry enterprises due to the information technology implementation by the example of the tube bending technological process. The article analyzes tube bending kinds and current technique. In addition, a potential risks analysis in a tube bending technological process is carried out in terms of information security.

  18. Thermogravimetric analysis of anthracite and waste plastics by iso-conversional method

    International Nuclear Information System (INIS)

    Ren, Shan; Zhang, Jianliang

    2013-01-01

    Highlights: • Co-combustion kinetic analysis of solid fuels was made by iso-conversional method. • Thermodynamic and kinetic parameters of combustion for blends were determined. • WP can improve the combustion characteristic of high ash anthracite. • Reasonable utilization the energy of WP is important for industrial production. - Abstract: Combustion mechanisms and kinetics of plastics-coal blends with 0, 10, 20, 40 and 100% waste plastics (WP) are studied separately by thermogravimetric analysis (TGA) from ambient temperature to 900 °C in air atmosphere. These blends are combusted at different heating rates. The results indicate that, with the increase of waste plastics content, the combustion processes of blends could be divided into one stage, two stages, three stages and one stage. Meanwhile, the ignition and final temperatures of them both decrease. The maximum weight loss rate of WP is much higher than that of other samples. The iso-conversional method is used for the kinetic analysis of the non-isothermal thermogravimetric data and results indicate that, when the waste plastics content varied from 0% to 40%, the values of activation energy increase from 113.3 kJ mol −1 to 156.0 kJ mol −1 , and the value of activation energy for pure WP is 278.8 kJ mol −1

  19. Analysis and computation of microstructure in finite plasticity

    CERN Document Server

    Hackl, Klaus

    2015-01-01

    This book addresses the need for a fundamental understanding of the physical origin, the mathematical behavior, and the numerical treatment of models which include microstructure. Leading scientists present their efforts involving mathematical analysis, numerical analysis, computational mechanics, material modelling and experiment. The mathematical analyses are based on methods from the calculus of variations, while in the numerical implementation global optimization algorithms play a central role. The modeling covers all length scales, from the atomic structure up to macroscopic samples. The development of the models ware guided by experiments on single and polycrystals, and results will be checked against experimental data.

  20. Spring-back of flexible roll forming bending process

    International Nuclear Information System (INIS)

    Zhang, Y; Kim, D H; Jung, D W

    2015-01-01

    Simulations are now widely used in the field of roll forming because of their convenience. Simulations provide a low cost, secure and fast analysis tool. Flexible roll forming provides the desired shapes with a one time forming process. For roll forming, the velocity of the sheet and friction are important factors to attain an ideal shape. Because it is a complicated process, simulations provide a better understanding of the roll forming process. Simulations were peformed using ABAQUS software linked to elastic-plastic modules which we developed taking into account of interactions between these fields [1]. The application of this method makes it possible to highlight the strain-stress and mechanical behaviour laws and the spring-back. Thus, the flexible roll forming and bending process can be well described by the simulation software and guide the actual machine. (paper)

  1. Analysis of Usability in Furniture Production of Wood Plastic Laminated Board

    Directory of Open Access Journals (Sweden)

    Abdullah Cemil Ilçe

    2015-05-01

    Full Text Available The objective of this study was to manufacture a lightweight and easily producible wood plastic laminate (WPL board that could be used in the furniture sector. Eastern beech (Fagus orientalis L. veneer papels (A and hollow polycarbonate boards (B, both with a thickness of 4 mm, were laminated in different combinations using polyurethane (PUR and polychloroprene (PCR adhesives. The physical and mechanical properties of the WPL boards obtained were determined according to the principles specified in the EN 326-1, EN 317, EN 310, ASTM D1037, and ASTM D1761 standards. Subsequently, the specimens were compared with particle boards (PB, medium density fiberboards (MDF, and okoume plywoods (PW. According to the results, the AABAA, ABABA, and ABBBA combinations of the WPL materials had better physical properties, such as weight, water absorption, and swelling thickness, compared to the other composites. Furthermore, because the WPL materials had a high bending resistance, modulus of elasticity, and nail and screw withdrawal strength, they could be used instead of PB and MDF. The WPL material obtained within the scope of this study are suitable for furniture making.

  2. Elastic-plastic failure analysis of pressure burst tests of thin toroidal shells

    International Nuclear Information System (INIS)

    Jones, D.P.; Holliday, J.E.; Larson, L.D.

    1998-07-01

    This paper provides a comparison between test and analysis results for bursting of thin toroidal shells. Testing was done by pressurizing two toroidal shells until failure by bursting. An analytical criterion for bursting is developed based on good agreement between structural instability predicted by large strain-large displacement elastic-plastic finite element analysis and observed burst pressure obtained from test. The failures were characterized by loss of local stability of the membrane section of the shells consistent with the predictions from the finite element analysis. Good agreement between measured and predicted burst pressure suggests that incipient structural instability as calculated by an elastic-plastic finite element analysis is a reasonable way to calculate the bursting pressure of thin membrane structures

  3. Occipital bending in depression.

    Science.gov (United States)

    Maller, Jerome J; Thomson, Richard H S; Rosenfeld, Jeffrey V; Anderson, Rodney; Daskalakis, Zafiris J; Fitzgerald, Paul B

    2014-06-01

    There are reports of differences in occipital lobe asymmetry within psychiatric populations when compared with healthy control subjects. Anecdotal evidence and enlarged lateral ventricles suggests that there may also be a different pattern of curvature whereby one occipital lobe wraps around the other, termed 'occipital bending'. We investigated the prevalence of occipital bending in 51 patients with major depressive disorder (males mean age = 41.96 ± 14.00 years, females mean age = 40.71 ± 12.41 years) and 48 age- and sex-matched healthy control subjects (males mean age = 40.29 ± 10.23 years, females mean age = 42.47 ± 14.25 years) and found the prevalence to be three times higher among patients with major depressive disorder (18/51, 35.3%) when compared with control subjects (6/48, 12.5%). The results suggest that occipital bending is more common among patients with major depressive disorder than healthy subjects, and that occipital asymmetry and occipital bending are separate phenomena. Incomplete neural pruning may lead to the cranial space available for brain growth being restricted, or ventricular enlargement may exacerbate the natural occipital curvature patterns, subsequently causing the brain to become squashed and forced to 'wrap' around the other occipital lobe. Although the clinical implications of these results are unclear, they provide an impetus for further research into the relevance of occipital bending in major depression disorder. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. 3D Suspended Polymeric Microfluidics (SPMF3 with Flow Orthogonal to Bending (FOB for Fluid Analysis through Kinematic Viscosity

    Directory of Open Access Journals (Sweden)

    Mostapha Marzban

    2017-10-01

    Full Text Available Measuring of fluid properties such as dynamic viscosity and density has tremendous potential for various applications from physical to biological to chemical sensing. However, it is almost impossible to affect only one of these properties, as dynamic viscosity and density are coupled. Hence, this paper proposes kinematic viscosity as a comprehensive parameter which can be used to study the effect of fluid properties applicable to various fluids from Newtonian fluids, such as water, to non-Newtonian fluids, such as blood. This paper also proposes an ideal microplatform, namely polymeric suspended microfluidics (SPMF3, with flow plane orthogonal to the bending plane of the structure, along with tested results of various fluids covering a wide range of engineering applications. Kinematic viscosity, also called momentum diffusivity, considers changes in both fluid intermolecular forces and molecular inertia that define dynamic viscosity and fluid density, respectively. In this study a 3D suspended polymeric microfluidic system (SPMF3 was employed to detect changes in fluid parameters such as dynamic viscosity and density during fluid processes. Using this innovative design along with theoretical and experimental results, it is shown that, in fluids, the variations of fluid density and dynamic viscosity are not easily comprehensible due to their interconnectivity. Since any change in a fluid will affect both density and dynamic viscosity, measuring both of them is necessary to identify the fluid or process status. Finally, changes in fluid properties were analyzed using simulation and experiments. The experimental results with salt-DI water solution and milk with different fat concentrations as a colloidal fluid show that kinematic viscosity is a comprehensive parameter that can identify the fluids in a unique way using the proposed microplatform.

  5. Rapid discrimination of plastic packaging materials using MIR spectroscopy coupled with independent components analysis (ICA).

    Science.gov (United States)

    Kassouf, Amine; Maalouly, Jacqueline; Rutledge, Douglas N; Chebib, Hanna; Ducruet, Violette

    2014-11-01

    Plastic packaging wastes increased considerably in recent decades, raising a major and serious public concern on political, economical and environmental levels. Dealing with this kind of problems is generally done by landfilling and energy recovery. However, these two methods are becoming more and more expensive, hazardous to the public health and the environment. Therefore, recycling is gaining worldwide consideration as a solution to decrease the growing volume of plastic packaging wastes and simultaneously reduce the consumption of oil required to produce virgin resin. Nevertheless, a major shortage is encountered in recycling which is related to the sorting of plastic wastes. In this paper, a feasibility study was performed in order to test the potential of an innovative approach combining mid infrared (MIR) spectroscopy with independent components analysis (ICA), as a simple and fast approach which could achieve high separation rates. This approach (MIR-ICA) gave 100% discrimination rates in the separation of all studied plastics: polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS) and polylactide (PLA). In addition, some more specific discriminations were obtained separating plastic materials belonging to the same polymer family e.g. high density polyethylene (HDPE) from low density polyethylene (LDPE). High discrimination rates were obtained despite the heterogeneity among samples especially differences in colors, thicknesses and surface textures. The reproducibility of the proposed approach was also tested using two spectrometers with considerable differences in their sensitivities. Discrimination rates were not affected proving that the developed approach could be extrapolated to different spectrometers. MIR combined with ICA is a promising tool for plastic waste separation that can help improve performance in this field; however further technological improvements and developments are required before it can be applied

  6. A critical analysis of the biological impacts of plasticizers on wildlife

    Science.gov (United States)

    Oehlmann, Jörg; Schulte-Oehlmann, Ulrike; Kloas, Werner; Jagnytsch, Oana; Lutz, Ilka; Kusk, Kresten O.; Wollenberger, Leah; Santos, Eduarda M.; Paull, Gregory C.; Van Look, Katrien J. W.; Tyler, Charles R.

    2009-01-01

    This review provides a critical analysis of the biological effects of the most widely used plasticizers, including dibutyl phthalate, diethylhexyl phthalate, dimethyl phthalate, butyl benzyl phthalate and bisphenol A (BPA), on wildlife, with a focus on annelids (both aquatic and terrestrial), molluscs, crustaceans, insects, fish and amphibians. Moreover, the paper provides novel data on the biological effects of some of these plasticizers in invertebrates, fish and amphibians. Phthalates and BPA have been shown to affect reproduction in all studied animal groups, to impair development in crustaceans and amphibians and to induce genetic aberrations. Molluscs, crustaceans and amphibians appear to be especially sensitive to these compounds, and biological effects are observed at environmentally relevant exposures in the low ng l−1 to µg l−1 range. In contrast, most effects in fish (except for disturbance in spermatogenesis) occur at higher concentrations. Most plasticizers appear to act by interfering with the functioning of various hormone systems, but some phthalates have wider pathways of disruption. Effect concentrations of plasticizers in laboratory experiments coincide with measured environmental concentrations, and thus there is a very real potential for effects of these chemicals on some wildlife populations. The most striking gaps in our current knowledge on the impacts of plasticizers on wildlife are the lack of data for long-term exposures to environmentally relevant concentrations and their ecotoxicity when part of complex mixtures. Furthermore, the hazard of plasticizers has been investigated in annelids, molluscs and arthropods only, and given the sensitivity of some invertebrates, effects assessments are warranted in other invertebrate phyla. PMID:19528055

  7. Quantification of net carbon flux from plastic greenhouse vegetable cultivation: A full carbon cycle analysis

    International Nuclear Information System (INIS)

    Wang Yan; Xu Hao; Wu Xu; Zhu Yimei; Gu Baojing; Niu Xiaoyin; Liu Anqin; Peng Changhui; Ge Ying; Chang Jie

    2011-01-01

    Plastic greenhouse vegetable cultivation (PGVC) has played a vital role in increasing incomes of farmers and expanded dramatically in last several decades. However, carbon budget after conversion from conventional vegetable cultivation (CVC) to PGVC has been poorly quantified. A full carbon cycle analysis was used to estimate the net carbon flux from PGVC systems based on the combination of data from both field observations and literatures. Carbon fixation was evaluated at two pre-selected locations in China. Results suggest that: (1) the carbon sink of PGVC is 1.21 and 1.23 Mg C ha -1 yr -1 for temperate and subtropical area, respectively; (2) the conversion from CVC to PGVC could substantially enhance carbon sink potential by 8.6 times in the temperate area and by 1.3 times in the subtropical area; (3) the expansion of PGVC usage could enhance the potential carbon sink of arable land in China overall. - Highlights: → We used full carbon (C) cycle analysis to estimate the net C flux from cultivation. → The plastic greenhouse vegetable cultivation system in China can act as a C sink. → Intensified agricultural practices can generate C sinks. → Expansion of plastic greenhouse vegetable cultivation can enhance regional C sink. - The conversion from conventional vegetable cultivation to plastic greenhouse vegetable cultivation could substantially enhance carbon sink potential by 8.6 and 1.3 times for temperate and subtropical area, respectively.

  8. Elastic-plastic analysis of fracture mechanics test specimens. Part 2

    International Nuclear Information System (INIS)

    Talja, H.; Wallin, K.

    1984-12-01

    This is second part of the report of the research program 'Comparisons between computational and experimental elastic-plastic results' started at the Technical Research Centre of Finland in 1981. The first part of the research program was reported earlier and contained a two dimensional linear elastic finite element analysis of four specimen geometries (CT, RCT, ASTM-3P and Charpy-V) and testing and elastic-plastic analysis of the specimen (EGF71; 1TCT, material A 542). In this report the second part of the program containing the testing and 2-D elastic-plastic analyses of five specimens is described. The four specimen geometries mentioned above and two different materials (stainless steel AISI 304 and ferrite pressure vessel steel A533B) are considered. The following comparisons are presented in the report: load vs. load displacement curves, J-integral, crack opening displacement (COD), J vs. COD and the size of the plastic zone. The agreement between the computational and experimental results is quite good. Complete agreement can be achieved only with 3-dimensional calculation models. (author)

  9. Elastic-plastic-creep analysis of brazed carbon-carbon/OFHC divertor tile concepts for TPX

    International Nuclear Information System (INIS)

    Chin, E.; Reis, E.E.

    1995-01-01

    The 7.5 MW/m 2 heat flux requirements for the TPX divertor necessitate the use of high conductivity carbon-carbon (C-C) tiles that are brazed to annealed copper (OFHC) coolant tubes. Significant residual stresses are developed in the C-C tiles during the braze process due to large differences in the thermal expansion coefficients between these materials. Analyses which account for only the elastic-plastic strains developed in the OFHC tube may not accurately characterize the behavior of the tube during brazing. The elevated temperature creep behavior of the copper coolant tubes intuitively should reduce the calculated residual stresses in the C-C tiles. Two divertor tile concepts, the monoblock and the archblock, were analyzed for residual stress using 2-D finite element analysis for elastic-plastic-creep behavior of the OFHC tube during an assumed braze cooldown cycle. The results show that the inclusion of elevated temperature creep effects decrease the calculated residual stresses by only about 10% when compared to those analyses in which only elastic-plastic behavior of the OFHC is accounted for. The primary reason that creep effects at higher temperatures are not more significant is due to the low yield stress and nearly flat-top stress-strain curve of annealed OFHC. Since high temperature creep plays less of a role in the residual stress levels than previously thought, future scoping studies can be done in an elastic-plastic analysis with confidence that the stresses will be within approximately 10% of an elastic-plastic-creep analysis

  10. Characterization of wood plastic composites made from landfill-derived plastic and sawdust: Volatile compounds and olfactometric analysis

    International Nuclear Information System (INIS)

    Félix, Juliana S.; Domeño, Celia; Nerín, Cristina

    2013-01-01

    Graphical abstract: This work details the characterization of VOCs of WPC, produced from residual materials which would have landfills as current destination, and evaluates their odor profile. Highlights: ► More than 140 volatile compounds were identified in raw materials and WPC products. ► Markers were related to the thermal degradation, sawdust or coupling agents. ► WPC prototype showed a characteristic odor profile of burnt, sweet and wax-like. ► Aldehydes, carboxylic acids, ketones and phenols were odor descriptors of WPC. - Abstract: Application of wood plastic composites (WPCs) obtained from recycled materials initially intended for landfill is usually limited by their composition, mainly focused on release of volatile organic compounds (VOCs) which could affect quality or human safety. The study of the VOCs released by a material is a requirement for new composite materials. Characterization and quantification of VOCs of several WPC produced with low density polyethylene (LDPE) and polyethylene/ethylene vinyl acetate (PE/EVA) films and sawdust were carried out, in each stage of production, by solid phase microextraction in headspace mode (HS-SPME) and gas chromatography–mass spectrometry (GC–MS). An odor profile was also obtained by HS-SPME and GC–MS coupled with olfactometry analysis. More than 140 compounds were observed in the raw materials and WPC samples. Some quantified compounds were considered WPC markers such as furfural, 2-methoxyphenol, N-methylphthalimide and 2,4-di-tert-butylphenol. Hexanoic acid, acetic acid, 2-methoxyphenol, acetylfuran, diacetyl, and aldehydes were the most important odorants. None of the VOCs were found to affect human safety for use of the WPC

  11. Characterization of wood plastic composites made from landfill-derived plastic and sawdust: Volatile compounds and olfactometric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Félix, Juliana S., E-mail: jfelix@unizar.es [Department of Analytical Chemistry, I3A, EINA, University of Zaragoza (UNIZAR), Zaragoza 50018 (Spain); Domeño, Celia, E-mail: cdomeno@unizar.es [Department of Analytical Chemistry, I3A, EINA, University of Zaragoza (UNIZAR), Zaragoza 50018 (Spain); Nerín, Cristina, E-mail: cnerin@unizar.es [Department of Analytical Chemistry, I3A, EINA, University of Zaragoza (UNIZAR), Zaragoza 50018 (Spain)

    2013-03-15

    Graphical abstract: This work details the characterization of VOCs of WPC, produced from residual materials which would have landfills as current destination, and evaluates their odor profile. Highlights: ► More than 140 volatile compounds were identified in raw materials and WPC products. ► Markers were related to the thermal degradation, sawdust or coupling agents. ► WPC prototype showed a characteristic odor profile of burnt, sweet and wax-like. ► Aldehydes, carboxylic acids, ketones and phenols were odor descriptors of WPC. - Abstract: Application of wood plastic composites (WPCs) obtained from recycled materials initially intended for landfill is usually limited by their composition, mainly focused on release of volatile organic compounds (VOCs) which could affect quality or human safety. The study of the VOCs released by a material is a requirement for new composite materials. Characterization and quantification of VOCs of several WPC produced with low density polyethylene (LDPE) and polyethylene/ethylene vinyl acetate (PE/EVA) films and sawdust were carried out, in each stage of production, by solid phase microextraction in headspace mode (HS-SPME) and gas chromatography–mass spectrometry (GC–MS). An odor profile was also obtained by HS-SPME and GC–MS coupled with olfactometry analysis. More than 140 compounds were observed in the raw materials and WPC samples. Some quantified compounds were considered WPC markers such as furfural, 2-methoxyphenol, N-methylphthalimide and 2,4-di-tert-butylphenol. Hexanoic acid, acetic acid, 2-methoxyphenol, acetylfuran, diacetyl, and aldehydes were the most important odorants. None of the VOCs were found to affect human safety for use of the WPC.

  12. Application of micropolar plasticity to post failure analysis in geomechanics

    Science.gov (United States)

    Manzari, Majid T.

    2004-08-01

    A micropolar elastoplastic model for soils is formulated and a series of finite element analyses are employed to demonstrate the use of a micropolar continuum in overcoming the numerical difficulties encountered in application of finite element method in standard Cauchy-Boltzmann continuum. Three examples of failure analysis involving a deep excavation, shallow foundation, and a retaining wall are presented. In all these cases, it is observed that the length scale introduced in the polar continuum regularizes the incremental boundary value problem and allows the numerical simulation to be continued until a clear collapse mechanism is achieved. The issue of grain size effect is also discussed. Copyright

  13. Elastic, plastic, fracture analysis of masonry arches: A multi-span bridge case study

    Science.gov (United States)

    Lacidogna, Giuseppe; Accornero, Federico

    2018-01-01

    In this work a comparison is presented between elastic, plastic, and fracture analysis of the monumental arch bridge of Porta Napoli, Taranto (Italy). By means of a FEM model and applying the Mery's Method, the behavior of the curved structure under service loads is verified, while considering the Safe Theorem approach byHeyman, the ultimate carrying capacity of the structure is investigated. Moreover, by using Fracture Mechanics concepts, the damage process which takes place when the conditions assessed through linear elastic analysis are no longer valid, and before the set-in of the conditions established by means of the plastic limit analysis, is numerically analyzed. The study of these transitions returns an accurate and effective whole service life assessment of the Porta Napoli masonry arch bridge.

  14. Limit load solutions for piping branch junctions under out-of-plane bending

    International Nuclear Information System (INIS)

    Xu, Ying Hu; Lee, Kuk Hee; Jeon, Jun Young; Kim, Yun Jae

    2009-01-01

    Approximate plastic limit load solutions for piping branch junctions under out-of plane bending are obtained from detailed three-dimensional (3-D) FE limit analyses based on elastic-perfectly plastic materials with the small geometry change option. Two types of bending are considered; out-of-plane bending to the branch pipe and out-of-plane bending to the run pipe. Accordingly closed-form approximations are proposed for piping branch junctions under out-of-plane bending based on the FE results. The proposed solutions are valid for the branch-to-run pipe radius and thickness from 0.0 to 1.0, and the mean radius-to-thickness ratio of the run pipe from 2.0 to 20.0. And, this study provides effects of reinforcement area on plastic limit loads.

  15. The Ethics of Sharing Plastic Surgery Videos on Social Media: Systematic Literature Review, Ethical Analysis, and Proposed Guidelines.

    Science.gov (United States)

    Dorfman, Robert G; Vaca, Elbert E; Fine, Neil A; Schierle, Clark F

    2017-10-01

    Recent videos shared by plastic surgeons on social media applications such as Snapchat, Instagram, and YouTube, among others, have blurred the line between entertainment and patient care. This has left many in the plastic surgery community calling for the development of more structured oversight and guidance regarding video sharing on social media. To date, no official guidelines exist for plastic surgeons to follow. Little is known about the ethical implications of social media use by plastic surgeons, especially with regard to video sharing. A systematic review of the literature on social media use in plastic surgery was performed on October 31, 2016, with an emphasis on ethics and professionalism. An ethical analysis was conducted using the four principles of medical ethics. The initial search yielded 87 articles. Thirty-four articles were included for analyses that were found to be relevant to the use of social media in plastic surgery. No peer-reviewed articles were found that mentioned Snapchat or addressed the ethical implications of sharing live videos of plastic surgery on social media. Using the four principles of medical ethics, it was determined that significant ethical concerns exist with broadcasting these videos. This analysis fills an important gap in the plastic surgery literature by addressing the ethical issues concerning live surgery broadcasts on social media. Plastic surgeons may use the guidelines proposed here to avoid potential pitfalls.

  16. Ductile fracture of circumferentially cracked pipes subjected to bending loads

    International Nuclear Information System (INIS)

    Zahoor, A.; Kanninen, M.F.

    1981-01-01

    A plastic fracture mechanics methodology is presented for part-through cracks in pipes under bending. A previous analysis result on the behavior of part-through cracks in pipes is reviewed. Example quantitative results for the initiation and instability of radial growth of part-through cracks are presented and compared with the experimental data to demonstrate the applicability of the method. The analyses in our previous work are further developed to include the instability of circumferential growth of part-through cracks. Numerical results are then presented for a compliant piping system, under displacement controlled bending, which focus on (1) instability of radial growth (unstable wall breakthrough) and (2) instability of circumferential growth of the resulting throughthe-thickness crack. The combined results of the above two types of analyses are presented on a safety assessment diagram. This diagram defines a curve of critical combination of length and depth of part-through cracks which delineates leak from fracture. The effect of piping compliance on the leak-before-break assessment is discussed

  17. Ductile fracture of circumferentially cracked pipes subjected to bending loads

    Energy Technology Data Exchange (ETDEWEB)

    Zahoor, A.; Kanninen, M.F.

    1981-10-01

    A plastic fracture mechanics methodology is presented for part-through cracks in pipes under bending. A previous analysis result on the behavior of part-through cracks in pipes is reviewed. Example quantitative results for the initiation and instability of radial growth of part-through cracks are presented and compared with the experimental data to demonstrate the applicability of the method. The analyses in our previous work are further developed to include the instability of circumferential growth of part-through cracks. Numerical results are then presented for a compliant piping system, under displacement controlled bending, which focus on (1) instability of radial growth (unstable wall breakthrough) and (2) instability of circumferential growth of the resulting throughthe-thickness crack. The combined results of the above two types of analyses are presented on a safety assessment diagram. This diagram defines a curve of critical combination of length and depth of part-through cracks which delineates leak from fracture. The effect of piping compliance on the leak-before-break assessment is discussed.

  18. Comparative environmental analysis of waste brominated plastic thermal treatments

    International Nuclear Information System (INIS)

    Bientinesi, M.; Petarca, L.

    2009-01-01

    The aim of this research activity is to investigate the environmental impact of different thermal treatments of waste electric and electronic equipment (WEEE), applying a life cycle assessment methodology. Two scenarios were assessed, which both allow the recovery of bromine: (A) the co-combustion of WEEE and green waste in a municipal solid waste combustion plant, and (B) the staged-gasification of WEEE and combustion of produced syngas in gas turbines. Mass and energy balances on the two scenarios were set and the analysis of the life cycle inventory and the life cycle impact assessment were conducted. Two impact assessment methods (Ecoindicator 99 and Impact 2002+) were slightly modified and then used with both scenarios. The results showed that scenario B (staged-gasification) had a potentially smaller environmental impact than scenario A (co-combustion). In particular, the thermal treatment of staged-gasification was more energy efficient than co-combustion, and therefore scenario B performed better than scenario A, mainly in the impact categories of 'fossil fuels' and 'climate change'. Moreover, the results showed that scenario B allows a higher recovery of bromine than scenario A; however, Br recovery leads to environmental benefits for both the scenarios. Finally the study demonstrates that WEEE thermal treatment for energy and matter recovery is an eco-efficient way to dispose of this kind of waste

  19. AA, bending magnet, BLG

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    The very particular lattice of the AA required 2 types of dipole (bending magnets; BLG, long and narrow; BST, short and wide). The BLG had a steel length of 4.70 m, a good field width of 0.24 m, and a weight of about 70 t. Jean-Claude Brunet inspects the lower half of a BLG. For the BST magnets see 7811105 and 8006036.

  20. A new discrete Kirchhoff-Mindlin element based on Mindlin-Reissner plate theory and assumed shear strain fields. I - An extended DKT element for thick-plate bending analysis. II - An extended DKQ element for thick-plate bending analysis

    Science.gov (United States)

    Katili, Irwan

    1993-06-01

    A new three-node nine-degree-of-freedom triangular plate bending element is proposed which is valid for the analysis of both thick and thin plates. The element, called the discrete Kirchhoff-Mindlin triangle (DKMT), has a proper rank, passes the patch test for thin and thick plates in an arbitrary mesh, and is free of shear locking. As an extension of the DKMT element, a four-node element with 3 degrees of freedom per node is developed. The element, referred to as DKMQ (discrete Kirchhoff-Mindlin quadrilateral) is found to provide good results for both thin and thick plates without any compatibility problems.

  1. Analysis of phthalate migration to food simulants in plastic containers during microwave operations.

    Science.gov (United States)

    Moreira, Miriany A; André, Leiliane C; Cardeal, Zenilda L

    2013-12-30

    Phthalates used as plasticizers in the manufacture of household containers can potentially be transferred to foods that are stored or heated in these plastic containers. Phthalates are endocrine disruptor compounds (EDC) and are found in very low concentrations in foods, thus, highly sensitive analytical techniques are required for their quantification. This study describes the application of a new method developed for analyzing the migration of dibutylphthalate (DBP) and benzylbutylphthalate (BBP) from plastic food containers into liquid food simulants. This new method employs the technique of solid phase microextraction cooled with liquid nitrogen. The analysis was conducted by gas chromatography/mass spectrometry (GC/MS) using a polyacrylate fiber. Ultrapure water was used as a simulant for liquids foods, and both new and used plastic containers were placed in a domestic microwave oven for different periods of time at different power levels. The limits of detection for DBP and BBP were 0.08 µg/L and 0.31 µg/L, respectively. BBP was not found in the samples that were analyzed. DBP was found in concentrations ranging from containers that were used for a prolonged time, which correlated with increasing heating time.

  2. The knowledge, awareness, attitude and motivational analysis of plastic waste and household perspective in Malaysia.

    Science.gov (United States)

    Afroz, Rafia; Rahman, Ataur; Masud, Muhammad Mehedi; Akhtar, Rulia

    2017-01-01

    The focus of this study is to analyze the level of knowledge, awareness, and attitude toward plastic waste and to distinguish the key drivers that encourage the households in Kuala Lumpur, Malaysia, to participate in "No plastic campaign," This study used the logistic regression model to explain the factors that may affect the willingness to participate (WTP) of households in the campaign. In this study, it is found that 35 % of households are willing to participate in the campaign. The results of the study also indicate that people who are more informed and more convinced of their knowledge have a more positive attitude toward recycling than their counterparts do. Furthermore, this study provides additional evidence of the level and classification of importance of motivating factors for plastic recycling, using the modified average and coefficient of variation of the models. From the analysis, the factor "helps reduce landfill use" is found as the most important factor and the factor of "raising money for charity" is found as the least important factor that motivates households to participate in recycling. The determinations of the study suggest some strategies that could hold implications for government and households to boost them to participate in the campaign "No Plastic Bag."

  3. Analysis of Phthalate Migration to Food Simulants in Plastic Containers during Microwave Operations

    Directory of Open Access Journals (Sweden)

    Miriany A. Moreira

    2013-12-01

    Full Text Available Phthalates used as plasticizers in the manufacture of household containers can potentially be transferred to foods that are stored or heated in these plastic containers. Phthalates are endocrine disruptor compounds (EDC and are found in very low concentrations in foods, thus, highly sensitive analytical techniques are required for their quantification. This study describes the application of a new method developed for analyzing the migration of dibutylphthalate (DBP and benzylbutylphthalate (BBP from plastic food containers into liquid food simulants. This new method employs the technique of solid phase microextraction cooled with liquid nitrogen. The analysis was conducted by gas chromatography/mass spectrometry (GC/MS using a polyacrylate fiber. Ultrapure water was used as a simulant for liquids foods, and both new and used plastic containers were placed in a domestic microwave oven for different periods of time at different power levels. The limits of detection for DBP and BBP were 0.08 µg/L and 0.31 µg/L, respectively. BBP was not found in the samples that were analyzed. DBP was found in concentrations ranging from

  4. Caseload of NHS plastic surgeons in Scotland, 2005-2006: analysis of Scottish hospital activity data.

    Science.gov (United States)

    Brewster, Colin T; Shoaib, Taimur

    2009-04-01

    To assess the contemporary caseload of NHS plastic surgeons. Descriptive study. Scotland. Analysis of routinely collected NHS hospital activity data relating to the financial year 2005-2006. Number of inpatient/day-case episodes and bed-days by principal diagnosis and main operative procedure. During the study period, 12,844 inpatient and 9439 day-case episodes were recorded in 19,166 patients, accounting for 36,300 bed-days. There were more female patients, especially among middle-age groups. Socioeconomic deprivation was more common than expected (P accounted for a higher proportion of bed-days (37.3%) than neoplasms (23.8%). Only approximately half of all surgical procedures were assigned to the skin chapter of the OPCS-4 classification. Despite some limitations, this study provides an insight into the current caseload of NHS plastic surgeons working in Scotland. The data suggest that cosmetic surgery for purely aesthetic reasons represents a relatively small part of NHS plastic surgery activity in Scotland, and that the majority of caseload is in reconstructive plastic surgery.

  5. The optimization of phthalate analysis from plastic matrices by using GC/MS related techniques

    Science.gov (United States)

    Pusfitasari, Eka Dian; Hendarsyah, Hendris; Athaillah, Zatil Afrah

    2017-11-01

    Indication of malicious acts conducted by food vendors has been reported in many places in Indonesia and has been worrying the population. One of the issues is the indication that frying oil used by the vendors has been added with food packaging plastic to impart more crispy texture of the fried foods. One of the challenges for the monitoring process is to find suitable analytical method to identify this type of food adulteration. Because some food packaging, particularly from polyethylene group, contains plasticizer diethylhexylphthalate (DEHP), we intended to investigate the adulteration by detecting the phthalate compound. In this preliminary study, we focused on the optimization of GC equipment as well as the optimization of plastic extraction process with various types of solvents (hexane, dichloromethane, and acetonitrile) and extraction time (24, 48, and 72 hours). For 72-hour duration, treatment with solvent refreshment was also conducted to minimize solvent saturation effect. Our findings suggested that LOD and LOQ of the GC/MS instrument used for the DEHP analysis were 19.6 ng and 65.5 ng, respectively. In addition, it could be concluded that the process of plastic extraction through sonication for five minutes with n-hexane as a solvent resulted in the optimal value.

  6. Elastic-plastic analysis of high speed rotors with no plane of symmetry

    International Nuclear Information System (INIS)

    Anantha Ramu, S.

    1981-01-01

    A general method of analysis of elastic plastic shells has been developed. The material of the shell is assumed to obey von Mises yield condition and a stress strain law on the basis of deformation theory of plasticity. The method permits an easy iterative solution of the complete set of coupled nonlinear differential equations. The iterative procedure is essentially the solution of the elastic problem several times with different sets of loads. The solution finally yields among other things, the location of the elastic-plastic boundary in the shell wall. The second approach suggested is a three-dimensional hexahedral isoparametric solid element. The computer program developed is capable of modelling perfectly plastic, bilinear as well as nonlinear strain hardening behaviour of materials. As an example, a radial impeller is analysed by both the approaches by idealizing it as a rotating conical shell. The complete history of plastification of the shell wall as the speed increases is determined. The results of both approaches are found to be in good agreement with each other. (orig./HP)

  7. EBSD analysis of plastic deformation of copper foils by flexible pad laser shock forming

    Energy Technology Data Exchange (ETDEWEB)

    Nagarajan, Balasubramanian; Castagne, Sylvie [Nanyang Technological University, SIMTech-NTU Joint Laboratory (Precision Machining), Singapore (Singapore); Nanyang Technological University, School of Mechanical and Aerospace Engineering, Singapore (Singapore); Wang, Zhongke; Zheng, H.Y. [Nanyang Technological University, SIMTech-NTU Joint Laboratory (Precision Machining), Singapore (Singapore); Singapore Institute of Manufacturing Technology, Machining Technology Group, Singapore (Singapore)

    2015-11-15

    Flexible pad laser shock forming (FPLSF) is a new mold-free microforming process that induces high-strain-rate plastic deformation in thin metallic foils using laser-induced shock pressure and a hyperelastic flexible pad. This paper studies the plastic deformation behavior of copper foils formed through FPLSF by investigating surface hardness and microstructure. The microstructure of the foil surface before and after FPLSF is analyzed by electron backscatter diffraction technique using grain size distribution and grain boundary misorientation angle as analysis parameters. The surface hardness of the craters experienced a significant improvement after FPLSF; the top crater surface being harder than the bottom surface. The microstructure of the copper foil surface after FPLSF was found to be dominated by grain elongation, along with minor occurrences of subgrain formation, grain refinement, and high dislocation density regions. The results indicate that the prominent plastic deformation mechanism in FPLSF is strain hardening behavior rather than the typical adiabatic softening effect known to be occurring at high-strain-rates for processes such as electromagnetic forming, explosive forming, and laser shock forming. This significant difference in FPLSF is attributed to the concurrent reduction in plastic strain, strain rate, and the inertia effects, resulting from the FPLSF process configuration. Correspondingly, different deformation behaviors are experienced at top and bottom surfaces of the deformation craters, inducing the change in surface hardness and microstructure profiles. (orig.)

  8. Extractables analysis of single-use flexible plastic biocontainers.

    Science.gov (United States)

    Marghitoiu, Liliana; Liu, Jian; Lee, Hans; Perez, Lourdes; Fujimori, Kiyoshi; Ronk, Michael; Hammond, Matthew R; Nunn, Heather; Lower, Asher; Rogers, Gary; Nashed-Samuel, Yasser

    2015-01-01

    Studies of the extractable profiles of bioprocessing components have become an integral part of drug development efforts to minimize possible compromise in process performance, decrease in drug product quality, and potential safety risk to patients due to the possibility of small molecules leaching out from the components. In this study, an effective extraction solvent system was developed to evaluate the organic extractable profiles of single-use bioprocess equipment, which has been gaining increasing popularity in the biopharmaceutical industry because of the many advantages over the traditional stainless steel-based bioreactors and other fluid mixing and storage vessels. The chosen extraction conditions were intended to represent aggressive conditions relative to the application of single-use bags in biopharmaceutical manufacture, in which aqueous based systems are largely utilized. Those extraction conditions, along with a non-targeted analytical strategy, allowed for the generation and identification of an array of extractable compounds; a total of 53 organic compounds were identified from four types of commercially available single-use bags, the majority of which are degradation products of polymer additives. The success of this overall extractables analysis strategy was reflected partially by the effectiveness in the extraction and identification of a compound that was later found to be highly detrimental to mammalian cell growth. The usage of single-use bioreactors has been increasing in biopharmaceutical industry because of the appealing advantages that it promises regarding to the cleaning, sterilization, operational flexibility, and so on, during manufacturing of biologics. However, compared to its conventional counterparts based mainly on stainless steel, single-use bioreactors are more susceptible to potential problems associated with compound leaching into the bioprocessing fluid. As a result, extractable profiling of the single-use system has become

  9. The industrial metabolism of plastics : analysis of material flows, energy consumption and CO2 emissions in the lifecycle of plastics

    NARCIS (Netherlands)

    Joosten, Ludovicus Antonius Josephus

    2001-01-01

    This thesis deals with the question: Which are promising options for decreasing material consumption, energy consumption and CO2 emissions in the lifecycle of plastics? The research described in this thesis mainly focuses on measures that change the material system, i.e. measures that change the

  10. Nonlinear analysis of rc members using hardening plasticity and arc-length method

    International Nuclear Information System (INIS)

    Memon, B.A.; Su, X.

    2005-01-01

    A general framework for three-dimensional nonlinear finite element analysis of reinforced concrete is done. To make computations robust, reliable and make analysis more realistic hardening plasticity with arc-length method as path following technique is used to model material-nonlinear behavior of reinforced concrete. Hardening plasticity has the advantage over other plasticity formulations that it allows extension of framework for the analysis of softening region. Concrete is treated as eight-node isoparametric element and reinforcement is modeled as line element embedded in the body of isoparametric concrete element. Different methods of stress-scaling back to yield surfaces are tested and their performance is compared. Severe convergence problems are encountered as solution process approaches singularity points; specially limit points; along load displacement curve in nonlinear analysis. To overcome the problem, cylindrical arc-length method is used. The use of the method not only tackles the issue of singularity points but also deals with load-step size problem. While marching along load-displacement path identification of singularity points is done by using singularity indicator, for the purpose various singularity test functions are implemented. Although most of the individual techniques are already well established, the framework is completely new one. A computer implementation of the proposed frame work is written in FORTRAN. Numerical examples are solved to illustrate the validity of proposed framework. Comparison of the outcome of proposed framework is made with experimental observations. two sets of the results are found in good agreement. (author)

  11. Hydraulic separation of plastic wastes: Analysis of liquid-solid interaction.

    Science.gov (United States)

    Moroni, Monica; Lupo, Emanuela; La Marca, Floriana

    2017-08-01

    The separation of plastic wastes in mechanical recycling plants is the process that ensures high-quality secondary raw materials. An innovative device employing a wet technology for particle separation is presented in this work. Due to the combination of the characteristic flow pattern developing within the apparatus and density, shape and size differences among two or more polymers, it allows their separation into two products, one collected within the instrument and the other one expelled through its outlet ducts. The kinematic investigation of the fluid flowing within the apparatus seeded with a passive tracer was conducted via image analysis for different hydraulic configurations. The two-dimensional turbulent kinetic energy results strictly connected to the apparatus separation efficacy. Image analysis was also employed to study the behaviour of mixtures of passive tracer and plastic particles with different physical characteristics in order to understand the coupling regime between fluid and solid phases. The two-dimensional turbulent kinetic energy analysis turned out to be fundamental to this aim. For the tested operating conditions, two-way coupling takes place, i.e., the fluid exerts an influence on the plastic particle and the opposite occurs too. Image analysis confirms the outcomes from the investigation of the two-phase flow via non-dimensional numbers (particle Reynolds number, Stokes number and solid phase volume fraction). Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Quality of Life and Aesthetic Plastic Surgery: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Dreher, Rodrigo; Blaya, Carolina; Tenório, Juliana L C; Saltz, Renato; Ely, Pedro B; Ferrão, Ygor A

    2016-09-01

    Quality of life (QoL) is an important outcome in plastic surgery. However, authors use different scales to address this subject, making it difficult to compare the outcomes. To address this discrepancy, the aim of this study was to perform a systematic review and a random effect meta-analysis. The search was made in two electronic databases (LILACS and PUBMED) using Mesh and non-Mesh terms related to aesthetic plastic surgery and QoL. We performed qualitative and quantitative analyses of the gathered data. We calculated a random effect meta-analysis with Der Simonian and Laird as variance estimator to compare pre- and postoperative QoL standardized mean difference. To check if there is difference between aesthetic surgeries, we compared reduction mammoplasty to other aesthetic surgeries. Of 1,715 identified, 20 studies were included in the qualitative analysis and 16 went through quantitative analysis. The random effect of all aesthetic surgeries shows that QoL improved after surgery. Reduction mammoplasty has improved QoL more than other procedures in social functioning and physical functioning domains. Aesthetic plastic surgery increases QoL. Reduction mammoplasty seems to have better improvement compared with other aesthetic surgeries.

  13. Bend-twist coupling potential of wind turbine blades

    DEFF Research Database (Denmark)

    Fedorov, Vladimir; Berggreen, Christian

    2014-01-01

    -twist coupling magnitude of up to 0.2 is feasible to achieve in the baseline blade structure made of glass-fiber reinforced plastics. Further, by substituting the glass-fibers with carbon-fibers the coupling effect can be increased to 0.4. Additionally, the effect of introduction of bend-twist coupling...

  14. Dynamic shear-bending buckling experiments of cylindrical shells

    International Nuclear Information System (INIS)

    Hagiwara, Y.; Akiyama, H.

    1995-01-01

    Dynamic experimental studies of the plastic shear/bending buckling of cylindrical shells were performed. They clarified the inelastic response reduction and the seismic margin of FBR reactor vessels. The test results were incorporated into the draft of the seismic buckling design guidelines of FBR. (author). 15 refs., 3 figs

  15. Generalization of a global model for reinforced concrete beams under combined axial force and bending moments

    International Nuclear Information System (INIS)

    Bairrao, R.; Millard, A.; Barbe, B.

    1991-01-01

    A large set of numerical data was obtained using a program recently developed. From the various results achieved, new analytical expressions for the definition of damage and plasticity criteria are being derived. The importance of taking into account the presence of general bending was highlighted. The extension to 3D bending, of the previous global models for reinforced concrete beams under combined axial force and bending, is under development. (author)

  16. Finite element limit analysis based plastic limit pressure solutions for cracked pipes

    International Nuclear Information System (INIS)

    Shim, Do Jun; Huh, Nam Su; Kim, Yun Jae; Kim, Young Jin

    2002-01-01

    Based on detailed FE limit analyses, the present paper provides tractable approximations for plastic limit pressure solutions for axial through-wall cracked pipe; axial (inner) surface cracked pipe; circumferential through-wall cracked pipe; and circumferential (inner) surface cracked pipe. Comparisons with existing analytical and empirical solutions show a large discrepancy in circumferential short through-wall cracks and in surface cracks (both axial and circumferential). Being based on detailed 3-D FE limit analysis, the present solutions are believed to be the most accurate, and thus to be valuable information not only for plastic collapse analysis of pressurised piping but also for estimating non-linear fracture mechanics parameters based on the reference stress approach

  17. Analysis of elastic-plastic dynamic response of reinforced concrete frame structure

    International Nuclear Information System (INIS)

    Li Zhongcheng

    2009-01-01

    Based on a set of data from seismic response test on an R/C frame, a force-based R/C beam fibre model with non-linear material properties and bond-slip effects are presented firstly in this paper, and then the applications to the tested R/C frame are presented to illustrate the model characteristics and to show the accuracy of seismic analysis including consideration of non-linear factors. It can be concluded that the elastic-plastic analysis is a potential step toward the accurate modelling for the dynamic analyses of R/C structures. Especially for the seismic safety re-evaluation of the existing NPPs, the elastic-plastic methodology with consideration of different non-linearities should be involved. (author)

  18. limit loads for wall-thinning feeder pipes under combined bending and internal pressure

    International Nuclear Information System (INIS)

    Je, Jin Ho; Lee, Kuk Hee; Chung, Ha Joo; Kim, Ju Hee; Han, Jae Jun; Kim, Yun Jae

    2009-01-01

    Flow Accelerated Corrosion (FAC) during inservice conditions produces local wall-thinning in the feeder pipes of CANDU. The Wall-thinning in the feeder pipes is main degradation mechanisms affecting the integrity of piping systems. This paper discusses the integrity assessment of wall-thinned feeder pipes using limit load analysis. Based on finite element limit analyses, this paper compare limit loads for wall-thinning feeder pipes under combined bending and internal pressure with proposed limit loads. The limit loads are determined from limit analyses based on rectangular wall-thinning and elastic-perfectly-plastic materials using the large geometry change.

  19. Low Cycle Fatigue of Steel in Strain Controled Cyclic Bending

    Directory of Open Access Journals (Sweden)

    Kulesa Anna

    2016-03-01

    Full Text Available The paper presents a comparison of the fatigue life curves based on test of 15Mo3 steel under cyclic, pendulum bending and tension-compression. These studies were analyzed in terms of a large and small number of cycles where strain amplitude is dependent on the fatigue life. It has been shown that commonly used Manson-Coffin-Basquin model cannot be used for tests under cyclic bending due to the impossibility of separating elastic and plastic strains. For this purpose, some well-known models of Langer and Kandil and one new model of authors, where strain amplitude is dependent on the number of cycles, were proposed. Comparing the results of bending with tension-compression it was shown that for smaller strain amplitudes the fatigue life for both test methods were similar, for higher strain amplitudes fatigue life for bending tests was greater than for tension-compression.

  20. Taylor-plasticity-based analysis of length scale effects in void growth

    KAUST Repository

    Liu, Junxian

    2014-09-25

    We have studied the void growth problem by employing the Taylor-based strain gradient plasticity theories, from which we have chosen the following three, namely, the mechanism-based strain gradient (MSG) plasticity (Gao et al 1999 J. Mech. Phys. Solids 47 1239, Huang et al 2000 J. Mech. Phys. Solids 48 99-128), the Taylor-based nonlocal theory (TNT; 2001 Gao and Huang 2001 Int. J. Solids Struct. 38 2615) and the conventional theory of MSG (CMSG; Huang et al 2004 Int. J. Plast. 20 753). We have addressed the following three issues which occur when plastic deformation at the void surface is unconstrained. (1) Effects of elastic deformation. Elasticity is essential for cavitation instability. It is therefore important to guarantee that the gradient term entering the Taylor model is the effective plastic strain gradient instead of the total strain gradient. We propose a simple elastic-plastic decomposition method. When the void size approaches the minimum allowable initial void size related to the maximum allowable geometrically necessary dislocation density, overestimation of the flow stress due to the negligence of the elastic strain gradient is on the order of lεY/R0 near the void surface, where l, εY and R0 are, respectively, the intrinsic material length scale, the yield strain and the initial void radius. (2) MSG intrinsic inconsistency, which was initially mentioned in Gao et al (1999 J. Mech. Phys. Solids 47 1239) but has not been the topic of follow-up studies. We realize that MSG higher-order stress arises due to the linear-strain-field approximation within the mesoscale cell with a nonzero size, lε. Simple analysis shows that within an MSG mesoscale cell near the void surface, the difference between microscale and mesoscale strains is on the order of (lε/R0)2, indicating that when lε/R0 ∼ 1.0, the higher-order stress effect can make the MSG result considerably different from the TNT or CMSG results. (3) Critical condition for cavitation instability

  1. ANALYSIS OF BIODEGRABILITY OF DEGRADABLE/BIODEGRADABLE PLASTIC MATERIAL IN CONTROLLED COMPOSTING ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Dana Adamcová

    2016-09-01

    Full Text Available We have obtained eight degradable/biodegradable materials based on starch (certified compostable, sample 4–7, HDPE mixed with totally degradable plastic additive (TDPA, sample 2 and polyethylene with the addition of pro-oxidant additive (d2w, sample 1. Composition of sample 3 has not been reported. The materials have been tested as to the rate and character of their degradability/biodegradability in controlled composting conditions. Experiment explored also the effect of degradation/biodegradation of plastic bags on compost quality. The material of the original samples was subjected to assessment using the Nicolet 6700 FT-IR spectrometer, the outcome thereof was obtaining infrared spectra of the samples. For further specification the original samples were tested using the thermogravimetrical analysis. The texture of the foils at different stages of degradation is presented in the Scanning Electron Microscope (SEM photographs. Plastic bags certified as compostable have degraded in laboratory conditions and their degradation had no impact on the quality and features of compost. Selected samples (4, 6 showed significant erosion on surface when subjected to the SEM analysis. Samples labeled (by their producers as 100% degradable (samples 1, 2, 3 did not show any visual signs of degradation and the process of degradation had no impact on the quality and features of compost. Only one of the samples (sample 1 showed certain erosion of surface when submitted for the SEM analysis.

  2. Bending-Tolerant Anodes for Lithium-Metal Batteries.

    Science.gov (United States)

    Wang, Aoxuan; Tang, Shan; Kong, Debin; Liu, Shan; Chiou, Kevin; Zhi, Linjie; Huang, Jiaxing; Xia, Yong-Yao; Luo, Jiayan

    2018-01-01

    Bendable energy-storage systems with high energy density are demanded for conformal electronics. Lithium-metal batteries including lithium-sulfur and lithium-oxygen cells have much higher theoretical energy density than lithium-ion batteries. Reckoned as the ideal anode, however, Li has many challenges when directly used, especially its tendency to form dendrite. Under bending conditions, the Li-dendrite growth can be further aggravated due to bending-induced local plastic deformation and Li-filaments pulverization. Here, the Li-metal anodes are made bending tolerant by integrating Li into bendable scaffolds such as reduced graphene oxide (r-GO) films. In the composites, the bending stress is largely dissipated by the scaffolds. The scaffolds have increased available surface for homogeneous Li plating and minimize volume fluctuation of Li electrodes during cycling. Significantly improved cycling performance under bending conditions is achieved. With the bending-tolerant r-GO/Li-metal anode, bendable lithium-sulfur and lithium-oxygen batteries with long cycling stability are realized. A bendable integrated solar cell-battery system charged by light with stable output and a series connected bendable battery pack with higher voltage is also demonstrated. It is anticipated that this bending-tolerant anode can be combined with further electrolytes and cathodes to develop new bendable energy systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Gender differences in variability patterns of forward bending

    DEFF Research Database (Denmark)

    Villumsen, Morten; Madeleine, Pascal; Jørgensen, Marie Birk

    2016-01-01

    The variability pattern is highly relevant in the analysis of occupational physical exposures. It is hypothesized that gender differences exist in the variability pattern of forward bending between work and leisure.......The variability pattern is highly relevant in the analysis of occupational physical exposures. It is hypothesized that gender differences exist in the variability pattern of forward bending between work and leisure....

  4. A calculational round robin in elastic-plastic fracture mechanics

    International Nuclear Information System (INIS)

    Larsson, L.H.

    Eighteen organizations participated in this round robin which treated the same three-point bend problem as an ASTM round robin four years earlier. Overall deformation, J, CTOD and crack profile were the main results required using plane strain elastic-plastic finite element analysis for a monotonically increasing load up to a maximum deformation which was far beyond the elastic regime. All elastic solutions were accurate to within a few percent. In the elastic-plastic regime, however, there was a large scatter of the results, increasing with increasing plastic deformation and roughly of the same order as in the ASTM round robin which contained ten solutions. Apparently no significant progress has taken place in the state of the art of numerical EPFM analysis in four years time. The paper discusses the reasons for this scatter and draws tentative conclusions on the most suitable numerical analysis methods in EPFM. (Auth.)

  5. ANALYSIS OF DEPENDENCE OF THE FLOW TEMPERATURE OF THE PLASTICIZED POLYMER ON THE CHEMICAL STRUCTURE AND CONCENTRATION OF THE POLYMER AND THE PLASTICIZER

    Directory of Open Access Journals (Sweden)

    Askadskiy Andrey Aleksandrovich

    2012-10-01

    Full Text Available Polymeric materials are widely used in construction. The properties of polymeric construction materials vary to a substantial extent; their durability, thermal stability, frost resistance, waterproof and dielectric properties are particularly pronounced. Their properties serve as the drivers of the high market demand for these products. These materials are applied as finishing materials, molded sanitary engineering products and effective thermal insulation and water proofing materials. The authors analyze the influence of the chemical structure and structural features of polymers on their properties. The authors consider flow and vitrification temperatures of polymers. These temperatures determine the parameters of polymeric products, including those important for the construction process. The analysis of influence of concentration of the plasticizer on the vitrification temperature is based on the two basic theories. In accordance with the first one, reduction of the vitrification temperature is proportionate to the molar fraction of the injected plasticizer. According to the second concept, reduction of the vitrification temperature is proportionate to the volume fraction of the injected solvent. Dependencies of the flow temperature on the molecular weight and the molar fraction of the plasticizer are derived for PVC. As an example, two plasticizers were considered, including dibutyl sebacate and dioctylftalatalate. The basic parameters of all mixtures were calculated through the employment of "Cascade" software programme (A.N. Nesmeyanov Institute of Organoelemental Connections, Russian Academy of Sciences.

  6. Elastic-plastic analysis of an axi-symmetric problem by a finite element method

    International Nuclear Information System (INIS)

    Isozaki, Toshikuni

    1984-06-01

    Generally speaking, many structures are designed and fabricated on the basis of an axi-symmetric structure. Finite Element Method is the capable method to solve these axi-symmetric problems beyond the elastic limit. As the first step to solve these problems, the computer program for the elastic-plastic analysis of the axi-symmetric problem is composed. The basic program is based upon that described in Zienkiewicz's text book to solve the elastic plane stress problem, taking the plastic stress matrix by Yamada's method into consideration and it is converted to solve the axi-symmetric problem. For the verification of the program, the plane strain problem of a cylindrical tube under internal pressure was solved. The computed results were compared with those shown in ADINA's user's manual. They showed close agreement. (author)

  7. UTILIZATION OF STEREOLOGY FOR QUANTITATIVE ANALYSIS OF PLASTIC DEFORMATION OF FORMING PIECES

    Directory of Open Access Journals (Sweden)

    Maroš Martinkovič

    2012-01-01

    Full Text Available Mechanical working leads to final properties of forming pieces, which are affected by conditions of production technology. Utilization of stereology leads to the detail analysis of three-dimensional plastic deformed material structure by different forming technologies, e.g. forging, extruding, upsetting, metal spinning, drawing etc. The microstructure of cold drawing wires was analyzed. Grain boundaries orientation was measured on the parallel section of wire with a different degree of deformation and direct axis plastic deformation was evaluated in bulk formed part. The strain of probes on their sections was obtained using stereology by measurement of degree of grain boundary orientation which was converted to deformation using model of conversion of grain boundary orientation degree to deformation.

  8. Analysis of the influence of plastic deformations in fatigue and crack process by numerical simulation

    International Nuclear Information System (INIS)

    Rahimian, Mohammad.

    1981-06-01

    The aim of this work is to analyze, by numerical simulation the characteristics of the stresses and deformations at the bottom of cracks when plasticity is taken into account. This analysis is performed as from theoretical results laid down in the literature and makes it possible to understand the different solutions obtained from Hencky's deformation law or from the incremental theory. The role of plastic deformation is discussed in depth in the study of fatigue cracks. The problems linked to the fixed crack are studied in the first two chapters. The problems linked to the propagation of cracks are discussed in the following chapters. The fourth chapter is an application of the preceding results and knowledge to fatigue [fr

  9. AGS superconducting bending magnets

    International Nuclear Information System (INIS)

    Robins, K.E.; Sampson, W.B.; McInturff, A.D.; Dahl, P.F.; Abbatiello, F.; Aggus, J.; Bamberger, J.; Brown, D.; Damm, R.; Kassner, D.; Lasky, C.; Schlafke, A.

    1976-01-01

    Four large aperture superconducting bending magnets are being built for use in the experimental beams at the AGS. Each of these magnets is 2.5 m long and has a room temperature aperture of 20 cm. The magnets are similar in design to the dipoles being developed for ISABELLE and employ a low temperature iron core. Results are presented on the ''training'' behavior of the magnets and a comparison will be made with the smaller aperture versions of this design. The magnet field measurements include end fields and leakage fields as well as the harmonic components of the straight section of the magnet

  10. Strength tests of thin-walled elliptic duralumin cylinders in pure bending and in combined pure bending and torsion

    Science.gov (United States)

    Lundquist, Eugene E; Stowell, Elbridge Z

    1942-01-01

    An analysis is presented of the results of tests made by the Massachusetts Institute of Technology and by the National Advisory Committee for Aeronautics on an investigation of the strength of thin-walled circular and elliptic cylinders in pure bending and in combined torsion and bending. In each of the loading conditions, the bending moments were applied in the plane of the major axis of the ellipse.

  11. Forming and bending of metal foams

    International Nuclear Information System (INIS)

    Nebosky, Paul; Tyszka, Daniel; Niebur, Glen; Schmid, Steven

    2004-01-01

    This study examines the formability of a porous tantalum foam, known as trabecular metal (TM). Used as a bone ingrowth surface on orthopedic implants, TM is desirable due to its combination of high strength, low relative density, and excellent osteoconductive properties. This research aims to develop bend and stretch forming as a cost-effective alternative to net machining and EDM for manufacturing thin parts made of TM. Experimentally, bending about a single axis using a wiping die was studied by observing cracking and measuring springback. It was found that die radius and clearance strongly affect the springback properties of TM, while punch speed, embossings, die radius and clearance all influence cracking. Depending on the various combinations of die radius and clearance, springback factor ranged from .70-.91. To examine the affect of the foam microstructure, bending also was examined numerically using a horizontal hexagonal mesh. As the hexagonal cells were elongated along the sheet length, elastic springback decreased. This can be explained by the earlier onset of plastic hinging occurring at the vertices of the cells. While the numerical results matched the experimental results for the case of zero clearance, differences at higher clearances arose due to an imprecise characterization of the post-yield properties of tantalum. By changing the material properties of the struts, the models can be modified for use with other open-cell metallic foams

  12. Analysis of {sup 210}Pb in water samples with plastic scintillation resins

    Energy Technology Data Exchange (ETDEWEB)

    Lluch, E.; Barrera, J. [Department of Analytical Chemistry, University of Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain); Tarancón, A., E-mail: alex.tarancon@ub.edu [Department of Analytical Chemistry, University of Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain); Bagán, H. [Department of Pure and Applied Biochemistry, Lund University, Getingevägen 60, Hus II, 22100 SE, Lund (Sweden); García, J.F. [Department of Analytical Chemistry, University of Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain)

    2016-10-12

    {sup 210}Pb is a radioactive lead isotope present in the environment as member of the {sup 238}U decay chain. Since it is a relatively long-lived radionuclide (T{sub 1/2} = 22.2 years), its analysis is of interest in radiation protection and the geochronology of sediments and artwork. Here, we present a method for analysing {sup 210}Pb using plastic scintillation resins (PSresins) packaged in solid-phase extraction columns (SPE cartridge). The advantages of this method are its selectivity, the low limit of detection, as well as reductions in the amount of time and reagents required for analysis and the quantity of waste generated. The PSresins used in this study were composed of a selective extractant (4′,4″(5″)-Di-tert-butyldicyclohexano-18-crown-6 in 1-octanol) covering the surface of plastic scintillation microspheres. Once the amount of extractant (1:1/4) and medium of separation (2 M HNO{sub 3}) were optimised, PSresins in SPE cartridges were calibrated with a standard solution of {sup 210}Pb. {sup 210}Pb could be fully separated from its daughters, {sup 210}Bi and {sup 210}Po, with a recovery value of 91(3)% and detection efficiency of 44(3)%. Three spiked water samples (one underground and two river water samples) were analysed in triplicates with deviations lower than 10%, demonstrating the validity of the PS resin method for {sup 210}Pb analysis. - Highlights: • A plastic scintillation resin for selective analysis of {sup 210}Pb has been developed. • A commercial SPE cartridge has been use for separation and scintillation counting. • {sup 210}Pb separation from {sup 210}Bi and {sup 210}Po is achieved with a 91(3)% of recovery. • The method is valid for analysis of {sup 210}Pb in river water samples.

  13. [Independence in Plastic Surgery - Benefit or Barrier? Analysis of the Publication Performance in Academic Plastic Surgery Depending on Varying Organisational Structures].

    Science.gov (United States)

    Schubert, C D; Leitsch, S; Haertnagl, F; Haas, E M; Giunta, R E

    2015-08-01

    Despite its recognition as an independent specialty, at German university hospitals the field of plastic surgery is still underrepresented in terms of independent departments with a dedicated research focus. The aim of this study was to analyse the publication performance within the German academic plastic surgery environment and to compare independent departments and dependent, subordinate organisational structures regarding their publication performance. Organisational structures and number of attending doctors in German university hospitals were examined via a website analysis. A pubmed analysis was applied to assess the publication performance (number of publications, cumulative impact factor, impact factor/publication, number of publications/MD, number of publications/unit) between 2009 and 2013. In a journal analysis the distribution of the cumulative impact factor and number of publications in different journals as well as the development of the impact factor in the top journals were analysed. Out of all 35 university hospitals there exist 12 independent departments for plastic surgery and 8 subordinate organisational structures. In 15 university hospitals there were no designated plastic surgery units. The number of attending doctors differed considerably between independent departments (3.6 attending doctors/unit) and subordinate organisational structures (1.1 attending doctors/unit). The majority of publications (89.0%) and of the cumulative impact factor (91.2%) as well as most of the publications/MD (54 publications/year) and publications/unit (61 publications/year) were created within the independent departments. Only in departments top publications with an impact factor > 5 were published. In general a negative trend regarding the number of publications (- 13.4%) and cumulative impact factor (- 28.9%) was observed. 58.4% of all publications were distributed over the top 10 journals. Within the latter the majority of articles were published in

  14. Plastic forming simulation analysis of marine engine crankshaft single-throw

    Directory of Open Access Journals (Sweden)

    LIU Peipei

    2016-08-01

    Full Text Available The research object is for marine engine crankshaft single-throw.A 3D model of the crankshaft single-throw blank and die in forging process is established by SolidWorks software,then the 3D model is imported into metal plastic forming CAE software DEFROM-3D to carry on the plastic forming simulation,to verify the relationship between the internal flow stress and the external deformation conditions in the process of metal plastic deformation under different strain rate and temperature,and to carry on the scientific analysis based on the obtained data.The result shows that the preset temperature is higher,the stress-strain curve is relatively lower when the strain rate is constant.Sample internal flow stress will be greater and the resistance to fatigue strength will be poorer at a higher strain rate when the temperature of the blank is constant.The result also provides a theoretical basis for further optimization design.

  15. Determination of the critical bending speeds of a multy-rotor shaft from the vibration signal analysis

    Science.gov (United States)

    Crâştiu, I.; Nyaguly, E.; Deac, S.; Gozman-Pop, C.; Bârgău, A.; Bereteu, L.

    2018-01-01

    The purpose of this paper is the development and validation of an impulse excitation technique to determine flexural critical speeds of a single rotor shaft and multy-rotor shaft. The experimental measurement of the vibroacoustic response is carried out by using a condenser microphone as a transducer. By the means of Modal Analysis using Finite Element Method (FEM), the natural frequencies and shape modes of one rotor and three rotor specimens are determined. The vibration responses of the specimens, in simple supported conditions, are carried out using algorithms based on Fast Fourier Transform (FFT). To validate the results of the modal parameters estimated using Finite Element Analysis (FEA) these are compared with experimental ones.

  16. 3-D Experimental Fracture Analysis at High Temperature

    Energy Technology Data Exchange (ETDEWEB)

    John H. Jackson; Albert S. Kobayashi

    2001-09-14

    T*e, which is an elastic-plastic fracture parameter based on incremental theory of plasticity, was determined numerically and experimentally. The T*e integral of a tunneling crack in 2024-T3 aluminum, three point bend specimen was obtained through a hybrid analysis of moire interferometry and 3-D elastic-plastic finite element analysis. The results were verified by the good agreement between the experimentally and numerically determined T*e on the specimen surface.

  17. Analysis of thin-walled cylindrical composite shell structures subject to axial and bending loads: Concept development, analytical modeling and experimental verification

    Science.gov (United States)

    Mahadev, Sthanu

    Continued research and development efforts devoted in recent years have generated novel avenues towards the advancement of efficient and effective, slender laminated fiber-reinforced composite members. Numerous studies have focused on the modeling and response characterization of composite structures with particular relevance to thin-walled cylindrical composite shells. This class of shell configurations is being actively explored to fully determine their mechanical efficacy as primary aerospace structural members. The proposed research is targeted towards formulating a composite shell theory based prognosis methodology that entails an elaborate analysis and investigation of thin-walled cylindrical shell type laminated composite configurations that are highly desirable in increasing number of mechanical and aerospace applications. The prime motivation to adopt this theory arises from its superior ability to generate simple yet viable closed-form analytical solution procedure to numerous geometrically intense, inherent curvature possessing composite structures. This analytical evaluative routine offers to acquire a first-hand insight on the primary mechanical characteristics that essentially govern the behavior of slender composite shells under typical static loading conditions. Current work exposes the robustness of this mathematical framework via demonstrating its potential towards the prediction of structural properties such as axial stiffness and bending stiffness respectively. Longitudinal ply-stress computations are investigated upon deriving the global stiffness matrix model for composite cylindrical tubes with circular cross-sections. Additionally, this work employs a finite element based numerical technique to substantiate the analytical results reported for cylindrically shaped circular composite tubes. Furthermore, this concept development is extended to the study of thin-walled, open cross-sectioned, curved laminated shells that are geometrically

  18. Comprehensive nonlocal analysis of piezoelectric nanobeams with surface effects in bending, buckling and vibrations under magneto-electro-thermo-mechanical loading

    Science.gov (United States)

    Ebrahimi-Nejad, Salman; Boreiry, Mahya

    2018-03-01

    The bending, buckling and vibrational behavior of size-dependent piezoelectric nanobeams under thermo-magneto-mechano-electrical environment are investigated by performing a parametric study, in the presence of surface effects. The Gurtin-Murdoch surface elasticity and Eringen’s nonlocal elasticity theories are applied in the framework of Euler–Bernoulli beam theory to obtain a new non-classical size-dependent beam model for dynamic and static analyses of piezoelectric nanobeams. In order to satisfy the surface equilibrium equations, cubic variation of stress with beam thickness is assumed for the bulk stress component which is neglected in classical beam models. Results are obtained for clamped - simply-supported (C-S) and simply-supported - simply-supported (S-S) boundary conditions using a proposed analytical solution method. Numerical examples are presented to demonstrate the effects of length, surface effects, nonlocal parameter and environmental changes (temperature, magnetic field and external voltage) on deflection, critical buckling load and natural frequency for each boundary condition. Results of this study can serve as benchmarks for the design and analysis of nanostructures of magneto-electro-thermo-elastic materials.

  19. Experimental Analysis of Mast Lifting and Bending Forces on Vibration Patterns Before and After Pinion Reinstallation in an OH-58 Transmission Test Rig

    Science.gov (United States)

    Huff, Edward M.; Lewicki, David G.; Tumer, Irem Y.; Decker, Harry; Barszez, Eric; Zakrajsek, James J.; Norvig, Peter (Technical Monitor)

    2000-01-01

    As part of a collaborative research program between NASA Ames Research Center (ARC), NASA Glenn Research Center (GRC), and the US Army Laboratory, a series of experiments is being performed in GRC's 500 HP OH-58 Transmission Test Rig facility and ARC's AH-I Cobra and OH-58c helicopters. The findings reported in this paper were drawn from Phase-I of a two-phase test-rig experiment, and are focused on the vibration response of an undamaged pinion gear operating in the transmission test rig. To simulate actual flight conditions, the transmission system was run at three torque levels, as well as two mast lifting and two mast bending levels. The test rig was also subjected to disassembly and reassembly of the main pinion housing to simulate the effect of maintenance operations. An analysis of variance based on the total power of the spectral distribution indicates the relative effect of each experimental factor, including Wong interactions with torque. Reinstallation of the main pinion assembly is shown to introduce changes in the vibration signature, suggesting the possibility of a strong effect of maintenance on HUMS design and use. Based on these results, further research will be conducted to compare these vibration responses with actual OH58c helicopter transmission vibration patterns.

  20. Paper-Plastic Hybrid Microfluidic Device for Smartphone-Based Colorimetric Analysis of Urine.

    Science.gov (United States)

    Jalal, Uddin M; Jin, Gyeong Jun; Shim, Joon S

    2017-12-19

    In this work, a disposable paper-plastic hybrid microfluidic lab-on-a-chip (LOC) has been developed and successfully applied for the colorimetric measurement of urine by the smartphone-based optical platform using a "UrineAnalysis" Android app. The developed device was cost-effectively implemented as a stand-alone hybrid LOC by incorporating the paper-based conventional reagent test strip inside the plastic-based LOC microchannel. The LOC device quantitatively investigated the small volume (40 μL) of urine analytes for the colorimetric reaction of glucose, protein, pH, and red blood cell (RBC) in integration with the finger-actuating micropump. On the basis of our experiments, the conventional urine strip showed large deviation as the reaction time goes by, because dipping the strip sensor in a bottle of urine could not control the reaction volume. By integrating the strip sensor in the LOC device for urine analysis, our device significantly improves the time-dependent inconstancy of the conventional dipstick-based urine strip, and the smartphone app used for image analysis enhances the visual assessment of the test strip, which is a major user concern for the colorimetric analysis in point-of-care (POC) applications. As a result, the user-friendly LOC, which is successfully implemented in a disposable format with the smartphone-based optical platform, may be applicable as an effective tool for rapid and qualitative POC urinalysis.

  1. Rigid-Plastic Post-Buckling Analysis of Columns and Quadratic Plates

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    2008-01-01

    the compressive load as a function of the transverse displacement. An estimate of the magnitude of the transverse displacement prior to the forming of the collapse mechanism is introduced into the compressive load function, determined by the virtual work equation, thereby revealing a qualified estimate...... yield lines accommodate differential rotations of rigid parts and the area “collapse” yield lines accommodate local area changes of the rigid parts thereby preserving compatibility of the rigid parts of a plate. The approach will be illustrated for rigid plastic column analysis and for a quadratic plate...

  2. Preliminary analysis of construction of the test drift in boom clay at Mol using plasticity solutions and finite elements

    International Nuclear Information System (INIS)

    Mair, R.J.; Taylor, R.N.; Higgins, K.G.; Potts, D.M.

    1989-01-01

    Analyses have been undertaken on an advancing tunnel heading at great depth in a clay formation corresponding to the test drift construction at Mol. Belgium. Simplifying assumptions enable plasticity solutions to be used to model the behaviour of a tunnel heading in a linear elastic-perfectly plastic soil. Finite element analysis with the same soil model has been undertaken of the test drift construction, assuming axisymmetric conditions. The results are compared with the plasticity solutions and with the measurements of lining stresses, soil movements and pore pressures by SCK/CEN. Good agreement is obtained between the plasticity solutions and finite element analysis. The measured immediate build-up of stress on the linings is well-predicted and reasonable agreement is obtained between predicted and measured soil movements. The measured pore-pressure changes are poorly predicted by the analyses

  3. experimental and analytical comparison of torsion, bending moment

    African Journals Online (AJOL)

    HOD

    In structural analysis and design, the effects of torsion are usually neglected ... bending and torsion, using these codes and experimental work; and validates the ..... [7] Kharagpur, I. Structural Analysis: Civil Engineering. Course Material (Vol.

  4. Crystal plasticity finite element analysis of deformation behaviour in SAC305 solder joint

    Science.gov (United States)

    Darbandi, Payam

    Due to the awareness of the potential health hazards associated with the toxicity of lead (Pb), actions have been taken to eliminate or reduce the use of Pb in consumer products. Among those, tin (Sn) solders have been used for the assembly of electronic systems. Anisotropy is of significant importance in all structural metals, but this characteristic is unusually strong in Sn, making Sn based solder joints one of the best examples of the influence of anisotropy. The effect of anisotropy arising from the crystal structure of tin and large grain microstructure on the microstructure and the evolution of constitutive responses of microscale SAC305 solder joints is investigated. Insights into the effects of key microstructural features and dominant plastic deformation mechanisms influencing the measured relative activity of slip systems in SAC305 are obtained from a combination of optical microscopy, orientation imaging microscopy (OIM), slip plane trace analysis and crystal plasticity finite element (CPFE) modeling. Package level SAC305 specimens were subjected to shear deformation in sequential steps and characterized using optical microscopy and OIM to identify the activity of slip systems. X-ray micro Laue diffraction and high energy monochromatic X-ray beam were employed to characterize the joint scale tensile samples to provide necessary information to be able to compare and validate the CPFE model. A CPFE model was developed that can account for relative ease of activating slip systems in SAC305 solder based upon the statistical estimation based on correlation between the critical resolved shear stress and the probability of activating various slip systems. The results from simulations show that the CPFE model developed using the statistical analysis of activity of slip system not only can satisfy the requirements associated with kinematic of plastic deformation in crystal coordinate systems (activity of slip systems) and global coordinate system (shape changes

  5. Does Formal Research Training Lead to Academic Success in Plastic Surgery? A Comprehensive Analysis of U.S. Academic Plastic Surgeons.

    Science.gov (United States)

    Lopez, Joseph; Ameri, Afshin; Susarla, Srinivas M; Reddy, Sashank; Soni, Ashwin; Tong, J W; Amini, Neda; Ahmed, Rizwan; May, James W; Lee, W P Andrew; Dorafshar, Amir

    2016-01-01

    It is currently unknown whether formal research training has an influence on academic advancement in plastic surgery. The purpose of this study was to determine whether formal research training was associated with higher research productivity, academic rank, and procurement of extramural National Institutes of Health (NIH) funding in plastic surgery, comparing academic surgeons who completed said research training with those without. This was a cross-sectional study of full-time academic plastic surgeons in the United States. The main predictor variable was formal research training, defined as completion of a postdoctoral research fellowship or attainment of a Doctor of Philosophy (PhD). The primary outcome was scientific productivity measured by the Hirsh-index (h-index, the number of publications, h that have at least h citations each). The secondary outcomes were academic rank and NIH funding. Descriptive, bivariate, and multiple regression statistics were computed. A total of 607 academic surgeons were identified from 94 Accreditation Council for Graduate Medical Education-accredited plastic surgery training programs. In all, 179 (29.5%) surgeons completed formal research training. The mean h-index was 11.7 ± 9.9. And, 58 (9.6%) surgeons successfully procured NIH funding. The distribution of academic rank was the following: endowed professor (5.4%), professor (23.9%), associate professor (23.4%), assistant professor (46.0%), and instructor (1.3%). In a multiple regression analysis, completion of formal research training was significantly predictive of a higher h-index and successful procurement of NIH funding. Current evidence demonstrates that formal research training is associated with higher scientific productivity and increased likelihood of future NIH funding. Copyright © 2016 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  6. Simplified elastic-plastic analysis of reinforced concrete structures - design method for self-restraining stress

    International Nuclear Information System (INIS)

    Aihara, S.; Atsumi, K.; Ujiie, K.; Satoh, S.

    1981-01-01

    Self-restraining stresses generate not only moments but also axial forces. Therefore the moment and force equilibriums of cross section are considered simultaneously, in combination with other external forces. Thus, under this theory, two computer programs are prepared for. Using these programs, the design procedures which considered the reduction of self-restraining stress, become easy if the elastic design stresses, which are separated normal stresses and self-restraining stresses, are given. Numerical examples are given to illustrate the application of the simplified elastic-plastic analysis and to study its effectiveness. First this method is applied to analyze an upper shielding wall in MARK-2 type's Reactor building. The results are compared with those obtained by the elastic-plastic analysis of Finite Element Method. From this comparison it was confirmed that the method described, had adequate accuracy for re-bar design. As a second example, Mat slab of Reactor building is analyzed. The quantity of re-bars calculated by this method, comes to about two third of re-bars less than those required when self-restraining stress is considered as normal stress. Also, the self-restraining stress reduction factor is about 0.5. (orig./HP)

  7. Peak stresses shift from femoral tunnel aperture to tibial tunnel aperture in lateral tibial tunnel ACL reconstructions: a 3D graft-bending angle measurement and finite-element analysis.

    Science.gov (United States)

    Van Der Bracht, Hans; Tampere, Thomas; Beekman, Pieter; Schepens, Alexander; Devriendt, Wouter; Verdonk, Peter; Victor, Jan

    2018-02-01

    To investigate the effect of tibial tunnel orientation on graft-bending angle and stress distribution in the ACL graft. Eight cadaveric knees were scanned in extension, 45°, 90°, and full flexion. 3D reconstructions with anatomically placed anterior cruciate ligament (ACL) grafts were constructed with Mimics 14.12 ® . 3D graft-bending angles were measured for classic medial tibial tunnels (MTT) and lateral tibial tunnels (LTT) with different drill-guide angles (DGA) (45°, 55°, 65°, and 75°). A pivot shift was performed on 1 knee in a finite-element analysis. The peak stresses in the graft were calculated for eight different tibial tunnel orientations. In a classic anatomical ACL repair, the largest graft-bending angle and peak stresses are seen at the femoral tunnel aperture. The use of a different DGA at the tibial side does not change the graft-bending angle at the femoral side or magnitude of peak stresses significantly. When using LTT, the largest graft-bending angles and peak stresses are seen at the tibial tunnel aperture. In a classic anatomical ACL repair, peak stresses in the ACL graft are found at the femoral tunnel aperture. When an LTT is used, peak stresses are similar compared to classic ACL repairs, but the location of the peak stress will shift from the femoral tunnel aperture towards the tibial tunnel aperture. the risk of graft rupture is similar for both MTTs and LTTs, but the location of graft rupture changes from the femoral tunnel aperture towards the tibial tunnel aperture, respectively. I.

  8. Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide

    OpenAIRE

    Kim, Gun-Hee; Lee, Jeong-Won; Seo, Tae-Il

    2013-01-01

    Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this stud...

  9. Environmental and economic life cycle analysis of plastic waste management options. A review

    OpenAIRE

    Bernardo, C. A.; Simões, Carla L.; Pinto, Lígia

    2016-01-01

    In recent years, rising worldwide plastic consumption led to the generation of increasing amounts of plastic waste and to the awareness of the importance of its management. In that framework, the present work describes how Life Cycle Assessment (LCA) and economic assessment methodologies can be used for evaluating environmental and economic impacts of alternative plastic waste management systems. The literature on LCA of plastic waste management systems is vast and the results reported are ge...

  10. [Systematic analysis of the readability of patient information on the websites of clinics for plastic surgery].

    Science.gov (United States)

    Esfahani, B Janghorban; Faron, A; Roth, K S; Schaller, H-E; Medved, F; Lüers, J-C

    2014-12-01

    The Internet is becoming increasing-ly important as a source of information for patients in medical issues. However, many patients have problems to adequately understand texts, especially with medical content. A basic requirement to understand a written text is the read-ability of a text. The aim of the present study was to examine texts on the websites of German -plastic-surgical hospitals with patient information regarding their readability. In this study, the read-ability of texts of 27 major departments of plastic and Hand surgery in Germany was systematically analysed using 5 recognised readability indices. First, texts were searched based on 20 representative key words and themes. Thereafter, texts were assigned to one of 3 major themes in order to enable statistical analysis. In addition to the 5 readability indices, further objective text parameters were also recorded. Overall, 288 texts were found for analyzation. Most articles were found on the topic of "handsurgery" (n=124), less were found for "facial plastic surgery" (n=80) and "flaps, breast and reconstructive surgery" (n=84). Consistently, all readability indices showed a poor readability for the vast majority of analysed texts with the text appearing readable only for readers with a higher educational level. No significant differences in readability were found between the 3 major themes. Especially in the communication of medical information, it is important to consider the knowledge and education of the addressee. The texts studied consistently showed a readability that is understandable only for academics. Thus, a large part of the intended target group is probably not reached. In order to adequately deliver online information material, a revision of the analysed internet texts appears to be recommendable. © Georg Thieme Verlag KG Stuttgart · New York.

  11. A Study on U-bending Technology using Rotary Draw Bending

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Ok-gyu; Kim, Won-seok [BHI Co., Gyunsang-Namdo (Korea, Republic of); Ku, Tae-wan [Pusan National Univ., Busan (Korea, Republic of)

    2014-10-15

    In the steam generator, heat transfer phenomenon for producing the steam between the primary system of the nuclear reactor and the secondary one occurs around the heat transfer tube. That is, the primary coolant with high temperature(320 .deg.. C) and high pressure(157Kgf/cm2) derived from the reactor flows in the heat transfer tube, and the secondary one runs out that tube. Therefore, it is able to mention that the heat transfer tube itself is a boundary of the heat transfer phenomenon. The heat transfer tube bundle of each steam generator used for the PWR and the PHWR(Pressurized Heavy Water Reactor) is generally composed of about 8,000-13,000 U-tubes. And these tubes are the core component as the structural and heat transfer material in the steam generator, which is in charge of cooling about 70% of the cooling surface of the primary system. For achieving the U-bending process with the thin walled tube, generally, a mandrel could be inserted in the tube according to the bending radius. But when the bending radius is small, the tube U-bending process could be also performed without the mandrel. In this study, numerical and experimental investigations on the U-bending process for producing the heat transfer tubes by using the straight and long tubes were carried out with the consideration of the elastic recovery after the U-bending. In the numerical approach, finite element analysis scheme was adopted with a commercial code, ABAQUS Implicit/Explicit. As the precedent study, the related experiment was also performed to verify the predicted results on the ovality and the minimum wall thickness of the U-bending heat transfer tube. Furthermore, its bending process was also conducted to analyze the deformation behavior for the Alloy 690 tube. In this study, the U-bending process was considered to simulate and manufactured the heat transfer tube used for the steam generator. To investigate the deformation behavior of the U-bending process, and a series of the

  12. A Cost-Effectiveness Analysis for Incineration or Recycling of Dutch Household Plastics

    NARCIS (Netherlands)

    Gradus, R.H.J.M.; Nillesen, P; Dijkgraaf, E.; Koppen, R. van

    2017-01-01

    The cost-effectiveness of two different plastic waste treatment options is compared. This paper evaluates the recycling of plastic waste with the more conventional incineration of plastic waste, using data for the Netherlands. Both options have specific revenues and costs. The main benefit from

  13. Collapse Scenarios of High-Rise Buildings Using Plastic Limit Analysis

    Directory of Open Access Journals (Sweden)

    G. Liu

    2009-01-01

    Full Text Available The Twin Towers of the World Trade Center (WTC in New York, USA collapsed on 11 September, 2001. The incident is regarded as the most severe disaster for high-rise buildings in history. Investigations into the collapse scenarios are still being conducted. Possible collapse scenarios assessed by local and international experts were reported. Another possible collapse scenario of the WTC based on two hypotheses was proposed in this paper, and the idea of plastic limit analysis was applied to evaluate the approximate limit load. According to the theory analysis and numerical calculations, a conclusion can be drawn that the large fires, aroused by the terrorist attack, play a significant role on the collapse of the WTC.

  14. Nonlinear analysis of pre-stressed concrete containment vessel (PCCV) using the damage plasticity model

    Energy Technology Data Exchange (ETDEWEB)

    Shokoohfar, Ahmad; Rahai, Alireza, E-mail: rahai@aut.ac.ir

    2016-03-15

    Highlights: • This paper describes nonlinear analyses of a 1:4 scale model of a (PCCV). • Coupled temp-disp. analysis and concrete damage plasticity are considered. • Temperature has limited effects on correct failure mode estimation. • Higher pre-stressing forces have limited effects on ultimate radial displacements. • Anchorage details of liner plates leads to prediction of correct failure mode. - Abstract: This paper describes the nonlinear analyses of a 1:4 scale model of a pre-stressed concrete containment vessel (PCCV). The analyses are performed under pressure and high temperature effects with considering anchorage details of liner plate. The temperature-time history of the model test is considered as an input boundary condition in the coupled temp-displacement analysis. The constitutive model developed by Chang and Mander (1994) is adopted in the model as the basis for the concrete stress–strain relation. To trace the crack pattern of the PCCV concrete faces, the concrete damage plasticity model is applied. This study includes the results of the thermal and mechanical behaviors of the PCCV subject to temperature loading and internal pressure at the same time. The test results are compared with the analysis results. The analysis results show that the temperature has little impact on the ultimate pressure capacity of the PCCV. To simulate the exact failure mode of the PCCV, the anchorage details of the liner plates around openings should be maintained in the analytical models. Also the failure mode of the PCCV structure hasn’t influenced by hoop tendons pre-stressing force variations.

  15. Formulation of Forming Load in V-Bending

    Directory of Open Access Journals (Sweden)

    Koumura Yuki

    2016-01-01

    Full Text Available A novel method is described to calculate the forming load in V-bending by a press brake. The data of forming load are collected by FEM analysis. With an increase of the punch stroke in V-bending, the forming load increases gradually after the elastic limit, and then decreases after showing the maximum value. The proposal formulation to trace the variations in the forming load curve includes the calculating method of the load of the elastic limit, the maximum load in air bending and the variations of the forming load before/after the bending stroke of the maximum load. The calculated precision is confirmed by comparing with the measured load-stroke curves in V-bending with a press brake.

  16. Microsurgery: the top 50 classic papers in plastic surgery: a citation analysis.

    Science.gov (United States)

    Joyce, Cormac Weekes; Carroll, Sean Michael

    2014-03-01

    The number of citations that a published article has received reflects the importance of the paper in the particular area of practice. In microsurgery, thus far, which journal articles are cited most frequently is unknown. The purpose of this study was to identify and analyze the characteristics of the top 50 papers in the field of microsurgery in the plastic surgery literature. The 50 most cited papers published in high impact plastic surgery and microsurgery journals were identified. The articles were ranked in the order of the number of citations received. These 50 classic papers were analyzed for article type, journal distribution, and geographic and institutional origin. Six international journals contributed to the top 50 papers in microsurgery. The most cited paper reported on the early use of the vascularized bone graft and was cited 116 times. The top 50 papers originated from just 10 countries with the United States producing the most. The Preston and Northcote Community Hospital, Melbourne published 5 papers and this was the most productive institution in the top 50. These papers represent many important milestones in the relatively short history of microsurgery. Furthermore, our citation analysis provides useful information to budding authors as to what makes a paper attain a "classic" status.

  17. Analysis of thermal-plastic response of shells of revolution by numerical integration

    International Nuclear Information System (INIS)

    Leonard, J.W.

    1975-01-01

    An economic technique for the numerical analysis of the elasto-plastic behaviour of shells of revolution would be of considerable value in the nuclear reactor industry. A numerical method based on the numerical integration of the governing shell equations has been shown, for elastic cases, to be more efficient than the finite element method when applied to shells of revolution. In the numerical integration method, the governing differential equations of motion are converted into a set of initial-value problems. Each initial-value problem is integrated numerically between meridional boundary points and recombined so as to satisfy boundary conditions. For large-deflection elasto-plastic behaviour, the equations are nonlinear and, hence, are recombined in an iterative manner using the Newton-Raphson procedure. Suppression techniques are incorporated in order to eliminate extraneous solutions within the numerical integration procedure. The Reissner-Meissner shell theory for shells of revolution is adopted to account for large deflection and higher-order rotation effects. The computer modelling of the equations is quite general in that specific shell segment geometries, e.g. cylindrical, spherical, toroidal, conical segments, and any combinations thereof can be handled easily. (Auth.)

  18. Spectral Analysis Method of Plastic Scintillator-based Radiation Detector against Nuclear/Radiological Terrorism

    International Nuclear Information System (INIS)

    Kwak, Sung-Woo; Yoo, Ho-Sik; Jang, Sung Soon; Kim, Jung-Soo; Yoon, Wan-Ki

    2008-01-01

    In these days, the threats relating to nuclear or radioactive materials have become a matter of internationally increased grave concern. A plastic scintillation detector in radiation portal monitoring (RPM) application has been used to detect radioactive sources in steel scrap entering reprocessing facilities, and to detect illicit transport of radioactive material across border ports-of-entry. The detection systems for RPM application usually are large and can not easily be moved to a different location. For some situations, an inconspicuous and mobile system for the radioactive or nuclear material during road transport is needed. The mobile radiation detection system has employed a NaI- based radiation detector to detect and identify the material hidden in vehicle. There are some operational constraints - short measuring time, weak activity due to heavy shield of illegal source, long distance - of inspection system in such nuclear security applications. Due to these constraints, large area sensor is required to maximize its sensitivity. Large NaI material, however, is extremely expensive. In designing a radiation detector for prevention of illicit trafficking of nuclear or radioactive materials, the trade-off should be carefully optimized between performance and cost in order to achieve cost-effective inspection system. For the cost-effective mobile radiation detection system, this paper describes new spectral analysis method to use the crude spectroscopic information available from a plastic detector to discriminate other man-made radiation source from NORM

  19. Analysis of thermal-plastic response of shells of revolution by numerical integration

    International Nuclear Information System (INIS)

    Leonard, J.W.

    1975-01-01

    A numerical method based instead on the numerical integration of the governing shell equations has been shown, for elastic cases, to be more efficient than the finite element method when applied to shells of revolution. In the numerical integration method, the governing differential equations of motions are converted into a set of initial-value problems. Each initial-value problem is integrated numerically between meridional boundary points and recombined so as to satisfy boundary conditions. For large-deflection elasto-plastic behavior, the equations are nonlinear and, hence, are recombined in an iterative manner using the Newton-Raphson procedure. Suppression techniques are incorporated in order to eliminate extraneous solutions within the numerical integration procedure. The Reissner-Meissner shell theory for shells of revolution is adopted to account for large deflection and higher-order rotation effects. The computer modelling of the equations is quite general in that specific shell segment geometries, e.g. cylindrical, spherical, toroidal, conical segments, and any combinations thereof can be handled easily. The elasto-plastic constitutive relations adopted are in accordance with currently recommended constitutive equations for inelastic design analysis of FFTF Components. The Von Mises yield criteria and associated flow rule is used and the kinematic hardening law is followed. Examples are considered in which stainless steels common to LMFBR application are used

  20. Soil Plasticity Model for Analysis of Collapse Load on Layers Soil

    Directory of Open Access Journals (Sweden)

    Md Nujid Masyitah

    2016-01-01

    Full Text Available Natural soil consist of soil deposits which is a soil layer overlying a thick stratum of another soil. The bearing capacity of layered soil studies have been conducted using different approach whether theoretical, experimental and combination of both. Numerical method in computer programme has become a powerful tool in solving complex geotechnical problems. Thus in numerical modelling, stress-strain soil behaviour is well predicted, design and interpreted using appropriate soil model. It is also important to identify parameters and soil model involve in prediction real soil problem. The sand layer overlaid clay layer soil is modelled with Mohr-Coulomb and Drucker-Prager criterion. The bearing capacity in loaddisplacement analysis from COMSOL Multiphysics is obtained and presented. In addition the stress distribution and evolution of plastic strain for each thickness ratio below centre of footing are investigated. The results indicate the linear relation on load-displacement which have similar trend for both soil models while stress and plastic strain increase as thickness ratio increase.

  1. Optimization of Recycled Glass Fibre-Reinforced Plastics Gear via Integration of the Taguchi Method and Grey Relational Analysis

    Science.gov (United States)

    Mizamzul Mehat, Nik; Syuhada Zakarria, Noor; Kamaruddin, Shahrul

    2018-03-01

    The increase in demand for industrial gears has resulted in the increase in usage of plastic-matrix composites particularly glass fibre-reinforced plastics as the gear materials. The usage of these synthetic fibers is to enhance the mechanical strength and the thermal resistance of the plastic gears. Nevertheless, the production of large quantities of these synthetic fibre-reinforced composites poses a serious threat to the ecosystem. Comprehending to this fact, the present work aimed at investigating the effects of incorporating recycled glass fibre-reinforced plastics in various compositions particularly on dimensional stability and mechanical properties of gear produced with diverse injection moulding processing parameters setting. The integration of Grey relational analysis (GRA) and Taguchi method was adopted to evaluate the influence of recycled glass fibre-reinforced plastics and variation in processing parameters on gear quality. From the experimental results, the blending ratio was found as the most influential parameter of 56.0% contribution in both improving tensile properties as well as in minimizing shrinkage, followed by mould temperature of 24.1% contribution and cooling time of 10.6% contribution. The results obtained from the aforementioned work are expected to contribute to accessing the feasibility of using recycled glass fibre-reinforced plastics especially for gear application.

  2. A bend thickness sensitivity study of Candu feeder piping

    International Nuclear Information System (INIS)

    Li, M.; Aggarwal, M.L.; Meysner, A.; Micelotta, C.

    2005-01-01

    In CANDU reactors, feeder bends close to the connection at the fuel channel may be subjected to the highest Flow Accelerated Corrosion (FAC) and stresses. Feeder pipe stress analysis is crucial in the life extension of aging CANDU plants. Typical feeder pipes are interconnected by upper link plates and spacers. It is well known that the stresses at the bends are sensitive to the local bend thicknesses. It is also known from the authors' study (Li and et al, 2005) that feeder inter linkage effect is significant and cannot be ignored. The field measurement of feeder bend thickness is difficult and may be subjected to uncertainty in accuracy. Hence, it is desirable to know how the stress on a subject feeder could be affected by the bend thickness variation of the neighboring feeders. This effect cannot be evaluated by the traditional 'single' feeder model approach. In this paper, the 'row' and 'combined' models developed in the previous study (Li and et al, 2005), which include the feeder interactions, are used to investigate the sensitivity of bend thickness. A series of random thickness bounded by maximum and minimum measured values were applied to feeders in the model. The results show that an individual feeder is not sensitive to the bend thickness variation of the remaining feeders in the model, but depends primarily on its own bend thickness. The highest stress at a feeder always occurs when the feeder has the smallest possible bend thickness. A minimum acceptable bend thickness for individual feeders can be computed by an iterative computing process. The dependency of field thickness measurement and the amount of required analysis work can be greatly reduced. (authors)

  3. Analysis of Simple Creep Stress Calculation Methods for Creep Life Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jun Min; Lee, Han Sang; Kim, Yun Jae [Korea Univ., Daejeon (Korea, Republic of)

    2017-08-15

    Creep analysis takes much more time than elastic or elastic-plastic analysis. In this study, we conducted elastic and elastic-plastic analysis and compared the results with creep analysis results. In the elastic analysis, we used primary stress, which can be classified by the Mα-tangent method and stress intensities recommended in the ASME code. In the elastic-plastic analysis, we calculated the parameters recommended in the R5 code. For the FE models, a bending load, uniaxial load, and biaxial load were applied to the cross shaped welded plate, and a bending load and internal pressure were applied to the elbow pipe. To investigate the element size sensitivity, we conducted FE analysis for various element sizes for the cases where bending load was applied to the cross shaped welded plate. There was no significant difference between the creep.

  4. Development of suitable plastic standards for X-ray fluorescence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mans, Christian [University of Applied Sciences Muenster, Department of Chemical Engineering, Advanced Analytical Chemistry, Stegerwaldstr. 39, 48565 Steinfurt (Germany)], E-mail: c.mans@fh-muenster.de; Hanning, Stephanie [University of Applied Sciences Muenster, Department of Chemical Engineering, Advanced Analytical Chemistry, Stegerwaldstr. 39, 48565 Steinfurt (Germany)], E-mail: hanning@fh-muenster.de; Simons, Christoph [University of Applied Sciences Muenster, Department of Chemical Engineering, Advanced Analytical Chemistry, Stegerwaldstr. 39, 48565 Steinfurt (Germany)], E-mail: simons@fh-muenster.de; Wegner, Anne [University of Applied Sciences Muenster, Department of Chemical Engineering, Advanced Analytical Chemistry, Stegerwaldstr. 39, 48565 Steinfurt (Germany)], E-mail: awegner@fh-muenster.de; Janssen, Anton [University of Applied Sciences Muenster, Department of Chemical Engineering, Advanced Analytical Chemistry, Stegerwaldstr. 39, 48565 Steinfurt (Germany)], E-mail: janssena@fh-muenster.de; Kreyenschmidt, Martin [University of Applied Sciences Muenster, Department of Chemical Engineering, Advanced Analytical Chemistry, Stegerwaldstr. 39, 48565 Steinfurt (Germany)], E-mail: martin.kreyenschmidt@fh-muenster.de

    2007-02-15

    For the adoption of the EU directive 'Restriction on use of certain Hazardous Substances' and 'Waste Electrical and Electronic Equipment' using X-ray fluorescence analysis suitable standard materials are required. Plastic standards based on acrylonitrile-butadiene-styrene terpolymer, containing the regulated elements Br, Cd, Cr, Hg and Pb were developed and produced as granulates and solid bodies. The calibration materials were not generated as a dilution from one master batch but rather the element concentrations were distributed over nine independent calibration samples. This was necessary to enable inter-elemental corrections and empirical constant mass absorption coefficients. The produced standard materials are characterized by a homogenous element distribution, which is more than sufficient for X-ray fluorescence analysis. Concentrations for all elements except for Br could be determined by Inductively Coupled Plasma Atomic Emission Spectroscopy after microwave assisted digestion. The concentration of Br was determined by use of Neutron Activation Analysis at Hahn-Meitner-Institute in Berlin, Germany. The correlation of the X-ray fluorescence analysis measurements with the values determined using Inductively Coupled Plasma Atomic Emission Spectroscopy and Neutron Activation Analysis showed a very good linearity.

  5. Crystal Plasticity Finite Element Analysis of Loading-Unloading Behaviour in Magnesium Alloy Sheet

    International Nuclear Information System (INIS)

    Hama, Takayuki; Fujimoto, Hitoshi; Takuda, Hirohiko

    2010-01-01

    Magnesium alloy sheets exhibit strong inelastic response during unloading. In this study crystal plasticity finite element analysis of loading-unloading behaviour during uniaxial tension in a rolled magnesium alloy sheet was carried out, and the mechanism of this inelastic response was examined in detail in terms of macroscopic and mesoscopic deformations. The unloading behaviour obtained by the simulation was in good agreement with the experiment in terms of variation with stress of instantaneous tangent modulus during unloading. Variations of activities of each family of slip systems during the deformation showed that the activation of basal slip systems is the largest during unloading, and the slip direction during unloading is opposite from during loading. These results indicated that one of the factors of the inelastic behaviour during unloading is the fact that the basal slip systems are easily activated during unloading because of their low strengths.

  6. Analysis of a ceramic filled bio-plastic composite sandwich structure

    International Nuclear Information System (INIS)

    Habib Ullah, M.; Islam, M. T.

    2013-01-01

    Design and analysis of a ceramic-filled bio-plastic composite sandwich structure is presented. This proposed high-dielectric structure is used as a substrate for patch antennas. A meandered-strip line-fed fractal-shape patch antenna is designed and fabricated on a copper-laminated sandwich-structured substrate. Measurement results of this antenna show 44% and 20% of bandwidths with maximum gains of 3.45 dBi and 5.87 dBi for the lower and upper bands, respectively. The half-power beam widths of 104° and 78° have been observed from the measured radiation pattern at the two resonance frequencies 0.9 GHz and 2.5 GHz

  7. Analysis of a ceramic filled bio-plastic composite sandwich structure

    Energy Technology Data Exchange (ETDEWEB)

    Habib Ullah, M. [Institute of Space Science (ANGKASA), Universiti Kebangsaan Malaysia, Bangi Selangor 43600 (Malaysia); Department of Electrical, Electronic and System Engineering, Universiti Kebangsaan Malaysia, Bangi 43600 (Malaysia); Islam, M. T. [Institute of Space Science (ANGKASA), Universiti Kebangsaan Malaysia, Bangi Selangor 43600 (Malaysia)

    2013-11-25

    Design and analysis of a ceramic-filled bio-plastic composite sandwich structure is presented. This proposed high-dielectric structure is used as a substrate for patch antennas. A meandered-strip line-fed fractal-shape patch antenna is designed and fabricated on a copper-laminated sandwich-structured substrate. Measurement results of this antenna show 44% and 20% of bandwidths with maximum gains of 3.45 dBi and 5.87 dBi for the lower and upper bands, respectively. The half-power beam widths of 104° and 78° have been observed from the measured radiation pattern at the two resonance frequencies 0.9 GHz and 2.5 GHz.

  8. Elastic-plastic analysis of part-through crack propagation in piping and pressure vessels

    International Nuclear Information System (INIS)

    Souza, L.A. de; Ebecken, N.F.F.

    1986-01-01

    The shell structures, often used in the construction of reservoirs, pipings, pressure vessels, nuclear power plants, etc, with part-through crack along its thickness, are analysed, using a computer system developed by the finite element method. The surface is discretized with three-dimensional quadratic elements, degenerated in its mid-surface, such the fracture is simulated by scalar elements (non linear springs). The results are analysed by the stress intensity factor K Sub(I) and the strain energy release rate, which is known as J-integral. The analysis is performed in the elastic and elastic-plastic regime. The basic hipothesis and the formulation adopted in the derivation of the scalar elements are also shown. (Author) [pt

  9. Experimental tests on buckling of torispherical heads comparison with plastic bifurcation analysis

    International Nuclear Information System (INIS)

    Roche, R.L.; Autrusson, B.

    1984-06-01

    Sixteen torispherical heads have been tested under internal pressure. All these heads were made by cold spinning from mild steel plates. Deflections on the axis and in the knuckle region have been recorded. As an practical result of these experiments, buckling pressure is given for each tested head. It is also indicated the maximum pressure reached during the tests, this pressure is very higher than the buckling pressure. It is also seen that buckling pressure is little sensitive to initial geometric imperfections. These experimental buckling pressure are compared with computation results obtained by plastic bifurcation analysis. Five different models of bifurcation matrix have been considered. If tangent matrix is unconservative, the use of tangent modulus (in lieu of YOUNG's modulus) is overconservative. Finally a mixing of tangent normal modulus and secant shearing modulus seems to be a good enough model (not to far from experimental results, and with not to large standard deviation)

  10. Plastic Surgery

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Plastic Surgery KidsHealth / For Teens / Plastic Surgery What's in ... her forehead lightened with a laser? What Is Plastic Surgery? Just because the name includes the word " ...

  11. Applied research and development of neutron activation analysis - Development of the precise analysis method for plastic materials by the use of NAA

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kil Yong; Sim, Sang Kwan; Yoon, Yoon Yeol; Chun, Sang Ki [Korea Institute of Geology, Mining and Materials, Taejon (Korea)

    2000-04-01

    The demand for inorganic analysis of plastics has significantly increased in the fields of microelectronic, environmental, nuclear and resource recycling. The difficulties of chemical analysis methods have led to the application of NAA which has great advantages of non-destructivity, freedom from blank, high sensitivity. The goal of the present work is to optimize and to develop the NAA procedures for the inorganic analysis of plastics. Even though NAA has unique advantages, it has two problems for plastics. One is the contamination by metallic utensils during sample treatment and the other is destruction of sample ampule due to pressure build-up by hydrogen and methane gas formed from oxyhydrogenation reaction with neutrons. For the first problem, large plastics were cut to pieces after immersion in liquid nitrogen. And the second problem has been solved by making an aperture on top side of sample ampule. These research results have been applied to analysis of various plastic materials which were used in food, drug containers and toys for children. Moreover, korean irradiation rabbit could be produced by the application of the results and standard reference materials of plastics which were used for the analysis in XRF and ICP could be produced. 36 refs., 6 figs., 37 tabs (Author)

  12. [Analysis of phthalates in plastic food-packaging bags by thin layer chromatography].

    Science.gov (United States)

    Chen, Hui; Wang, Yuan; Zhu, Ruohua

    2006-01-01

    The method for simultaneous determination of four phthalates, namely dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) in plastic food-packaging bags by thin layer chromatography (TLC) was developed. The plastic food-packaging bags were extracted with ethanol by ultrasonication, then the mixture was filtrated through membrane (0.45 microm). The mixture of ethyl acetate-anhydrous ether-isooctane (1 : 4 : 15, v/v) was used as developing agent on the TLC silica gel plate for development. The filtered liquid was spotted on the TLC plate dealt by acetone, and detected with scanning wavelength of 275 nm and reference wavelength of 340 nm. The qualitative analysis of the phthalates was performed using the R(f) values of the chromatogram. The quantitative analysis was performed with external standard method. Good linearities were obtained for DMP, DEP, DBP and DEHP. The detection limits were 2.1 ng for DMP, 2.4 ng for DEP, 3.4 ng for DBP and 4.0 ng for DEHP. The relative standard deviations (RSDs) of the four phthalates were 2.8% - 3.5%. The recoveries of the four phthalate standards in real sample were 78.58% - 111.04%. The method presented has the advantages of high precision, high sensitivity, small sample size, and simple pretreatment . The method was used to detect the four phthalates in the food-packaging bags. The contents in real samples were close to the results by gas chromatography.

  13. Elastic-plastic stress analysis and ASME code evaluation of a bottomhead penetration in a reactor pressure vessel

    International Nuclear Information System (INIS)

    Ranganath, S.

    1979-01-01

    Nuclear pressure vessel components are designed to meet the requirements of Section III of the ASME Boiler and Pressure Vessel Code. Specifically, the design must satisfy the limits on stress range and fatigue usage prescribed in NB-3200, Section III ASME Code for the various design and operating conditions for the component. The Code requirements assure that the component does not experience gross yielding and that in general, elastic shakedown occurs following cyclic loading. When elastic stress analysis is performed this can be shown by meeting the limits in the Code on Primary and Primary plus Secondary (P+Q) stress intensities. However, when the P+Q limits cannot be met and elastic Shakedown cannot be demonstrated, plastic analysis may be performed to meet the requirements of the Code. This paper describes the elastic-plastic stress analysis of a Boiling Water Reactor Vessel bottom head in-core penetration and illustrates how plastic analysis can be used in ASME Code evaluations to show Code compliance. Details of the thermal analysis, elastic-plastic stress analysis and fatigue evaluation are presented and it is shown that the in-core penetration satisfies the code requirements. 6 refs

  14. Structural test and analysis of a model of a BWR suppression chamber support in the plastic regime

    International Nuclear Information System (INIS)

    Blumer, U.R.; Klaeui, E.; Bosshard, E.P.

    1991-01-01

    A BWR Mark I suppression pool support has been analysed and tested in the laboratory. The aim was the demonstration of the acceptability of hypothetical dynamic loadings resulting from simultaneous steam blowdown through all safety relief valves. The analysis has shown that plastic deformation will locally occur, which is difficult to assess purely theoretical. Therefore tests in reduced scale were performed that show the amount and distribution of plastic flow in the supports. The paper describes the elastic analysis, the theory of the scaling laws for the reduced scale test, the test and its results. It also shows the thermographical method that has been used to determine the plastic material flow in the support structure. (author)

  15. From macro- to microplastics - Analysis of EU regulation along the life cycle of plastic bags

    DEFF Research Database (Denmark)

    Steensgaard, Ida M; Syberg, Kristian; Rist, Sinja

    2017-01-01

    Plastic pollution and its environmental effects has received global attention the recent years. However, limited attention has so far been directed towards how plastics are regulated in a life cycle perspective and how regulatory gaps can be addressed in order to limit and prevent environmental...... exposure and hazards of macro- and microplastics. In this paper, we map European regulation taking outset in the life cycle perspective of plastic carrier bags: from plastic bag production to when it enters the environment. Relevant regulatory frameworks, directives and authorities along the life cycle...... are identified and their role in regulation of plastics is discussed. Most important regulations were identified as: the EU chemical Regulation, the Packaging and Packaging Waste Directive including the amending Directive regarding regulation of the consumption of lightweight plastic carrier bags, the Waste...

  16. Numerical analysis of turbulent flow and heat transfer in a square sectioned U-bend duct by elliptic-blending second moment closure

    International Nuclear Information System (INIS)

    Shin, Jong Keun; Choi, Young Don; An, Jeong Soo

    2007-01-01

    A second moment turbulence closure using the elliptic-blending equation is introduced to analyze the turbulence and heat transfer in a square sectioned U-bend duct flow. The turbulent heat flux model based on the elliptic concept satisfies the near-wall balance between viscous diffusion, viscous dissipation and temperature-pressure gradient correlation, and also has the characteristics of approaching its respective conventional high Reynolds number model far away from the wall. Also, the traditional GGDH heat flux model is compared with the present elliptic concept-based heat flux model. The turbulent heat flux models are closely linked to the elliptic blending second moment closure which is used for the prediction of Reynolds stresses. The predicted results show their reasonable agreement with experimental data for a square sectioned U-bend duct flow field adopted in the present study

  17. The influence of end constraints on smooth pipe bends

    International Nuclear Information System (INIS)

    Thomson, G.; Spence, J.

    1981-01-01

    With present trends in the power industries towards higher operating temperatures and pressures, problems associated with the design and safety assessment of pipework systems have become increasingly complex. Within such systems, the importance of smooth pipe bends is well established. The work which will be presented will attempt to clarify the situation and unify the results. An analytical solution of the problem of a linear elastic smooth pipe bend with end constraints under in-plane bending will be presented. The analysis will deal with constraints in the form of flanged tangents of any length. The analysis employs the theorem of minimum total potential energy with suitable kinematically admissible displacements in the form of Fourier series. The integrations and minimisation were performed numerically, thereby permitting the removal of several of the assumptions made by previous authors. Typical results for flexibilities will be given along with comparisons with other works. The differences in some earlier theory are clarified and other more recent work using different solution techniques is substantiated. The bend behaviour is shown to be strongly influenced by the pipe bend parameter, the bend angle, the tangent pipe length and the bend/cross-sectional radius ratio. (orig./GL)

  18. A Generalized Orthotropic Elasto-Plastic Material Model for Impact Analysis

    Science.gov (United States)

    Hoffarth, Canio

    Composite materials are now beginning to provide uses hitherto reserved for metals in structural systems such as airframes and engine containment systems, wraps for repair and rehabilitation, and ballistic/blast mitigation systems. These structural systems are often subjected to impact loads and there is a pressing need for accurate prediction of deformation, damage and failure. There are numerous material models that have been developed to analyze the dynamic impact response of polymer matrix composites. However, there are key features that are missing in those models that prevent them from providing accurate predictive capabilities. In this dissertation, a general purpose orthotropic elasto-plastic computational constitutive material model has been developed to predict the response of composites subjected to high velocity impacts. The constitutive model is divided into three components - deformation model, damage model and failure model, with failure to be added at a later date. The deformation model generalizes the Tsai-Wu failure criteria and extends it using a strain-hardening-based orthotropic yield function with a non-associative flow rule. A strain equivalent formulation is utilized in the damage model that permits plastic and damage calculations to be uncoupled and capture the nonlinear unloading and local softening of the stress-strain response. A diagonal damage tensor is defined to account for the directionally dependent variation of damage. However, in composites it has been found that loading in one direction can lead to damage in multiple coordinate directions. To account for this phenomena, the terms in the damage matrix are semi-coupled such that the damage in a particular coordinate direction is a function of the stresses and plastic strains in all of the coordinate directions. The overall framework is driven by experimental tabulated temperature and rate-dependent stress-strain data as well as data that characterizes the damage matrix and failure

  19. Rigid-Plastic Approximations for Predicting Plastic Deformation of Cylindrical Shells Subject to Dynamic Loading

    Directory of Open Access Journals (Sweden)

    Michelle S. Hoo Fatt

    1996-01-01

    Full Text Available A theoretical approach was developed for predicting the plastic deformation of a cylindrical shell subject to asymmetric dynamic loads. The plastic deformation of the leading generator of the shell is found by solving for the transverse deflections of a rigid-plastic beam/string-on-foundation. The axial bending moment and tensile force in the beam/string are equivalent to the longitudinal bending moments and membrane forces of the shell, while the plastic foundation force is equivalent to the shell circumferential bending moment and membrane resistances. Closed-form solutions for the transient and final deformation profile of an impulsive loaded shell when it is in a “string” state were derived using the eigenfunction expansion method. These results were compared to DYNA 3D predictions. The analytical predictions of the transient shell and final centerline deflections were within 25% of the DYNA 3D results.

  20. Inelastic seismic response of precast concrete frames with constructed plastic hinges

    Science.gov (United States)

    Sucuoglu, H.

    1995-07-01

    A modified seismic design concept is introduced for precast concrete frames in which beam plastic hinges with reduced yield capacities are constructed away from the precast beam-column connections arranged at the column faces. Plastic hinge location and yield capacity are employed as the basic parameters of an analytical survey in which the inelastic dynamic responses of a conventional precast frame and its modified counterparts are calculated and compared under two earthquake excitations by using a general purpose computer program for dynamic analysis of inelastic frames (left bracket) 1, 2 (right bracket). An optimum design is obtained by providing plastic hinges on precast beams located at one depth away from the beam ends, in which primary (negative) bending moment yield capacities are reduced between one-third and one-quarter of the beam design end moments. With such plastic hinge configurations, precast beam-column connections at the column faces can be designed to remain elastic under strong earthquake excitations.

  1. From perceptual to lexico-semantic analysis--cortical plasticity enabling new levels of processing.

    Science.gov (United States)

    Schlaffke, Lara; Rüther, Naima N; Heba, Stefanie; Haag, Lauren M; Schultz, Thomas; Rosengarth, Katharina; Tegenthoff, Martin; Bellebaum, Christian; Schmidt-Wilcke, Tobias

    2015-11-01

    Certain kinds of stimuli can be processed on multiple levels. While the neural correlates of different levels of processing (LOPs) have been investigated to some extent, most of the studies involve skills and/or knowledge already present when performing the task. In this study we specifically sought to identify neural correlates of an evolving skill that allows the transition from perceptual to a lexico-semantic stimulus analysis. Eighteen participants were trained to decode 12 letters of Morse code that were presented acoustically inside and outside of the scanner environment. Morse code was presented in trains of three letters while brain activity was assessed with fMRI. Participants either attended to the stimulus length (perceptual analysis), or evaluated its meaning distinguishing words from nonwords (lexico-semantic analysis). Perceptual and lexico-semantic analyses shared a mutual network comprising the left premotor cortex, the supplementary motor area (SMA) and the inferior parietal lobule (IPL). Perceptual analysis was associated with a strong brain activation in the SMA and the superior temporal gyrus bilaterally (STG), which remained unaltered from pre and post training. In the lexico-semantic analysis post learning, study participants showed additional activation in the left inferior frontal cortex (IFC) and in the left occipitotemporal cortex (OTC), regions known to be critically involved in lexical processing. Our data provide evidence for cortical plasticity evolving with a learning process enabling the transition from perceptual to lexico-semantic stimulus analysis. Importantly, the activation pattern remains task-related LOP and is thus the result of a decision process as to which LOP to engage in. © 2015 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc.

  2. Comprehensive Deformation Analysis of a Newly Designed Ni-Free Duplex Stainless Steel with Enhanced Plasticity by Optimizing Austenite Stability

    Science.gov (United States)

    Moallemi, Mohammad; Zarei-Hanzaki, Abbas; Eskandari, Mostafa; Burrows, Andrew; Alimadadi, Hossein

    2017-08-01

    A new metastable Ni-free duplex stainless steel has been designed with superior plasticity by optimizing austenite stability using thermodynamic calculations of stacking fault energy and with reference to literature findings. Several characterization methods comprising optical microscopy, magnetic phase measurements, X-ray diffraction (XRD) and electron backscattered diffraction were employed to study the plastic deformation behavior and to identify the operating plasticity mechanisms. The results obtained show that the newly designed duplex alloy exhibits some extraordinary mechanical properties, including an ultimate tensile strength of 900 MPa and elongation to fracture of 94 pct due to the synergistic effects of transformation-induced plasticity and twinning-induced plasticity. The deformation mechanism of austenite is complex and includes deformation banding, strain-induced martensite formation, and deformation-induced twinning, while the ferrite phase mainly deforms by dislocation slip. Texture analysis indicates that the Copper and Rotated Brass textures in austenite (FCC phase) and {001} texture in ferrite and martensite (BCC phases) are the main active components during tensile deformation. The predominance of these components is logically related to the strain-induced martensite and/or twin formation.

  3. Size dependence of energy storage and dissipation in a discrete dislocation plasticity analysis of static friction

    NARCIS (Netherlands)

    Deshpande, VS; Needleman, A; Van der Giessen, E; Deshpande, V.S.

    2005-01-01

    The initiation of frictional sliding between a flat-bottomed indenter and a planar single crystal substrate is analyzed using discrete dislocation plasticity. Plastic deformation is modeled through the motion of edge dislocations in an elastic solid with the lattice resistance to dislocation motion,

  4. A Cost-Effectiveness Analysis for Incineration or Recycling of Dutch Household Plastics

    NARCIS (Netherlands)

    R.H.J.M. Gradus (Raymond); R. van Koppen (Rick); E. Dijkgraaf (Elbert); P. Nillesen (Paul)

    2016-01-01

    textabstractThe cost-effectiveness of plastic recycling is compared to energy recovery from plastic incineration in a waste-to-energy plant using data for the Netherlands. Both options have specific benefits and costs. The benefits of recycling are the avoidance of both CO2 that otherwise would be

  5. Scalable parallel elastic-plastic finite element analysis using a quasi-Newton method with a balancing domain decomposition preconditioner

    Science.gov (United States)

    Yusa, Yasunori; Okada, Hiroshi; Yamada, Tomonori; Yoshimura, Shinobu

    2018-04-01

    A domain decomposition method for large-scale elastic-plastic problems is proposed. The proposed method is based on a quasi-Newton method in conjunction with a balancing domain decomposition preconditioner. The use of a quasi-Newton method overcomes two problems associated with the conventional domain decomposition method based on the Newton-Raphson method: (1) avoidance of a double-loop iteration algorithm, which generally has large computational complexity, and (2) consideration of the local concentration of nonlinear deformation, which is observed in elastic-plastic problems with stress concentration. Moreover, the application of a balancing domain decomposition preconditioner ensures scalability. Using the conventional and proposed domain decomposition methods, several numerical tests, including weak scaling tests, were performed. The convergence performance of the proposed method is comparable to that of the conventional method. In particular, in elastic-plastic analysis, the proposed method exhibits better convergence performance than the conventional method.

  6. Comprehensive Deformation Analysis of a Newly Designed Ni-Free Duplex Stainless Steel with Enhanced Plasticity by Optimizing Austenite Stability

    DEFF Research Database (Denmark)

    Moallemi, Mohammad; Zarei-Hanzaki, Abbas; Eskandari, Mostafa

    2017-01-01

    A new metastable Ni-free duplex stainless steel has been designed with superior plasticity by optimizing austenite stability using thermodynamic calculations of stacking fault energy and with reference to literature findings. Several characterization methods comprising optical microscopy, magnetic......, including an ultimate tensile strength of ~900 MPa and elongation to fracture of ~94 pct due to the synergistic effects of transformation-induced plasticity and twinning-induced plasticity. The deformation mechanism of austenite is complex and includes deformation banding, strain-induced martensite...... formation, and deformation-induced twinning, while the ferrite phase mainly deforms by dislocation slip. Texture analysis indicates that the Copper and Rotated Brass textures in austenite (FCC phase) and {001}〈110〉 texture in ferrite and martensite (BCC phases) are the main active components during...

  7. Quantitative analysis of plastic debris on recreational beaches in Mumbai, India.

    Science.gov (United States)

    Jayasiri, H B; Purushothaman, C S; Vennila, A

    2013-12-15

    Plastic litter was quantified on four sandy beaches in Mumbai. The mean abundance of 7.49 g and 68.83 items per square metre was recorded. The abundance of plastics significantly varied among the beaches showing an increasing trend in the southern part. The abundance of plastics by weight in Dadar was significantly higher than that in Aksa. The size fractionation of plastics proved that small particles (1-20 mm) are predominant with 41.85% microplastics (1-5 mm) which emphasizes the high risk to marine organisms due to possible ingestion. The highest quantity of microplastics was seen in Juhu beach (55.33%) followed by Versova, Aksa and Dadar. The major contributing factors for the abundance are beach usage for different activities such as recreational, religious and fishing which suggest that the land-based sources provide major inputs to plastic pollution in these beaches. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Optimization of the wavelength shifter ratio in a polystyrene based plastic scintillator through energy spectrum analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ye Won; Kim, Myung Soo; Yoo, Hyun Jun; Lee, Dae Hee; Cho, Gyu Seong [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Moon, Myung Kook [Neutron Instrumentation Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-02-15

    The scintillation efficiency of the polystyrene based plastic scintillator depends on the ratio of the wavelength shifters, organic fluors (PPO and POPOP). Thus, 24 samples of the plastic scintillator were fabricated in order to find out the optimum ratio of the wavelength shifters in the plastic scintillator. The fabricated plastic scintillators were trimmed through a cutting and polishing process. They were used in gamma energy spectrum measurement with the {sup 137}Cs emitting monoenergy photon with 662 keV for the comparison of the scintillation efficiency. As a result, it was found out that the scintillator sample with 1.00 g of PPO (2,5-Diphenyloxazole) and 0.50 g of POPOP (1,4-Bis(5-phnyl-2oxidazolyl)benzene) dissolved in 100 g of styrene solution has the optimum ratio in terms of the light yield of the polystyrene based plastic scintillator.

  9. From macro- to microplastics - Analysis of EU regulation along the life cycle of plastic bags.

    Science.gov (United States)

    Steensgaard, Ida M; Syberg, Kristian; Rist, Sinja; Hartmann, Nanna B; Boldrin, Alessio; Hansen, Steffen Foss

    2017-05-01

    Plastic pollution and its environmental effects has received global attention the recent years. However, limited attention has so far been directed towards how plastics are regulated in a life cycle perspective and how regulatory gaps can be addressed in order to limit and prevent environmental exposure and hazards of macro- and microplastics. In this paper, we map European regulation taking outset in the life cycle perspective of plastic carrier bags: from plastic bag production to when it enters the environment. Relevant regulatory frameworks, directives and authorities along the life cycle are identified and their role in regulation of plastics is discussed. Most important regulations were identified as: the EU chemical Regulation, the Packaging and Packaging Waste Directive including the amending Directive regarding regulation of the consumption of lightweight plastic carrier bags, the Waste Framework Directive and the Directive on the Landfill of Waste. The main gaps identified relate to lack of clear definitions of categories of polymers, unambitious recycling rates and lack of consideration of macro- and microplastics in key pieces of legislation. We recommend that polymers are categorized according to whether they are polymers with the same monomer constituents (homopolymers) or with different monomer constituents (copolymers) and that polymers are no longer exempt from registration and evaluation under REACH. Plastics should furthermore have the same high level of monitoring and reporting requirements as hazardous waste involving stricter requirements to labelling, recordkeeping, monitoring and control over the whole lifecycle. Finally, we recommend that more ambitious recycle and recovery targets are set across the EU. Regulation of the consumption of lightweight plastic carrier bags should also apply to heavyweight plastic carrier bags. Last, the Marine and Water Framework Directives should specifically address plastic waste affecting water quality

  10. What patients look for when choosing a plastic surgeon: an assessment of patient preference by conjoint analysis.

    Science.gov (United States)

    Waltzman, Joshua T; Scholz, Thomas; Evans, Gregory R D

    2011-06-01

    The knowledge of patient preference is crucial for plastic surgeons to determine optimal marketing strategies. Conjoint analysis is a statistical technique whereby research participants make a series of trade-offs. Analysis of these trade-offs reveals the relative importance of component attributes. This study will evaluate the relative importance of attributes that influence the selection and decision-making process when choosing a plastic surgeon. A questionnaire consisting of 18 plastic surgeon profiles was rated by 111 patients. Attributes analyzed were as follows: travel distance, number of years in practice, board certification status, method of referral, office décor, and procedure cost. A traditional full-profile conjoint analysis was performed. Subjects consisted of 10 men and 101 women (n = 111). Median age was 51 years (range, 19-72). The "mean importance" of the attributes are as follows: board certification status, 39.7%; method of referral, 23.5%; distance from home to office, 13.2%; office décor, 9.0%; number of years in practice, 7.5%; and cost of procedure, 7.2%. Internal validity checks showed a high correlation (Pearson ρ = 0.995; P market research in the health care system. The level of importance for each attribute reliably helps plastic surgeons to understand the preferences of their patients, thus being able to improve marketing strategies for private practices and institutions. The present study indicates that the most important attributes were board certification and method of referral.

  11. Bending characteristics of resin concretes

    Directory of Open Access Journals (Sweden)

    Ribeiro Maria Cristina Santos

    2003-01-01

    Full Text Available In this research work the influence of composition and curing conditions in bending strength of polyester and epoxy concrete is analyzed. Various mixtures of resin and aggregates were considered in view of an optimal combination. The Taguchi methodology was applied in order to reduce the number of tests, and in order to evaluate the influence of various parameters in concrete properties. This methodology is very useful for the planning of experiments. Test results, analyzed by this methodology, shown that the most significant factors affecting bending strength properties of resin concretes are the type of resin, resin content and charge content. An optimal formulation leading to a maximum bending strength was achieved in terms of material parameters.

  12. NRC concerns about steam generator tube U-bend failures

    International Nuclear Information System (INIS)

    Dillon, R.L.

    1981-01-01

    This paper concerns itself with genralized NRC regulatory policy regarding SGT failures and staff reports and opinions which may tend to influence the developing policy specific to U-bend failures. The most significant analysis at hand in predicting NRC policy on SGT U-bend failures is Marsh's Evaluation of Steam Generator Tube Rupture Events. Marsh sets out to describe and analyze the five steam generator tube ruptures that are known to NRC. All have occurred in the period 1975 to 1980

  13. FRICTION ANALYSIS ON SCRATCH DEFORMATION MODES OF VISCO-ELASTIC-PLASTIC MATERIALS

    Directory of Open Access Journals (Sweden)

    Budi Setiyana

    2013-11-01

    Full Text Available Understanding of abrasion resistance and associated surfaces deformation mechanisms is of primary importance in materials engineering and design. Instrumented scratch testing has proven to be a useful tool for characterizing the abrasion resistance of materials. Using a conical indenter in a scratch test may result in different deformation modes, like as elastic deformation, ironing, ductile ploughing and cutting. This paper presents the friction analysis of some deformation modes of visco-elastic-plastic behaving polymer materials, especially PEEK (poly ether ether ketone.In general, it is accepted that the friction consist of an adhesion and a deformation component, which can be assumed to be independent to each others. During a scratch test, the friction coefficient is influenced by some parameters, such as the sharpness of indenter, the deformation modes and the degree of elastic recovery. Results show that the adhesion component strongly influences the friction in the elastic and ironing deformation mode (scratching with a blunt cone, friction for the cutting deformation mode (scratching with a sharp cone is dominantly influenced by the deformation component. From the analysis, it can be concluded that the adhesion friction model is suitable for ironing - elastic deformation mode and the deformation friction model with elastic recovery is good for cutting mode. Moreover, the ductile ploughing mode is combination of the adhesion and plastic deformation friction model. ANALISIS FRIKSI PADA BENTUK DEFORMASI AKIBAT GORESAN PADA MATERIAL VISKO-ELASTIK-PLASTIK. Pemahaman tentang ketahanan abrasi dan deformasi permukaan  yang  menyertainya merupakan hal yang penting dalam rekayasa dan disain material. Peralatan uji gores terbukti ampuh untuk menyatakan ketahanan abrasi dari material. Pemakaian indenter kerucut dalam uji gores akan menghasilkan beberapa bentuk deformasi seperti halnya deformasi elastik, penyetrikaan, plowing dan pemotongan

  14. Analysis of References on the Plastic Surgery In-Service Training Exam.

    Science.gov (United States)

    Silvestre, Jason; Zhang, Alicia; Lin, Samuel J

    2016-06-01

    The Plastic Surgery In-Service Training Exam is a knowledge assessment tool widely used during plastic surgery training in the United States. This study analyzed literature supporting correct answer choices to determine highest yield sources, journal publication lag, and journal impact factors. Digital syllabi of 10 consecutive Plastic Surgery In-Service Training Exam administrations (2006 to 2015) were reviewed. The most-referenced articles, journals, and textbooks were determined. Mean journal impact factor and publication lag were calculated and differences were elucidated by section. Two thousand questions and 5386 references were analyzed. From 2006 to 2015, the percentage of journal citations increased, whereas textbook references decreased (p < 0.001). Plastic and Reconstructive Surgery was cited with greatest frequency (38.5 percent), followed by Clinics in Plastic Surgery (5.6 percent), Journal of Hand Surgery (American volume) (5.1 percent), and Annals of Plastic Surgery (3.8 percent). There was a trend toward less publication lag over the study period (p = 0.05), with a mean publication lag of 9.1 ± 9.0 years for all journal articles. Mean journal impact factor was 2.3 ± 4.3 and lowest for the hand and lower extremity section (1.7 ± 2.8; p < 0.001). The highest yield textbooks were elucidated by section. Plastic surgery faculty and residents may use these data to facilitate knowledge acquisition during residency.

  15. Improving formability of tube bending for a copper material using finite element simulation

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Duc Toan; Nnuyen, Dinh Thanh [Hungyen University of Technology and Education, Hungyen (Viet Nam); Kim, Young Suk [Kyungpook National University, Daegu (Korea, Republic of)

    2015-10-15

    Bending tubes are key products in many industries. The geometric parameters of the bending process are considered according to Taguchi's orthogonal array and then coupled with finite element simulation to predict and improve the formability of the tube bending process for copper JIS25A material. Three parameters, namely, mandrel diameter, distance between mandrel rings, and distance from the tip of the mandrel bar to the center of the base die, are selected to study their effects on the quality of the bending process. The variance analysis shows that the effect distribution of each parameter to bending quality is determined, and optimal conditions are adopted to conduct experiments.

  16. Emittance growth of bunched beams in bends

    International Nuclear Information System (INIS)

    Carlsten, B.E.; Raubenheimer, T.O.

    1995-01-01

    Talman [Phys. Rev. Lett. 56, 1429 (1986)] has proposed a novel relativistic effect that occurs when a charged particle beam is bent in the magnetic field from an external dipole. The consequence of this effect is that the space-charge forces from the particles do not exhibit the usual inverse-square energy dependence and some part of them are, in fact, independent of energy. This led to speculation that this effect could introduce significant emittance growth for a bending electron beam. Subsequently, it was shown that this effect's influence on the beam's transverse motion is canceled for a dc beam by a potential depression within the beam (to first order in the beam radius divided by the bend radius). In this paper, we extend the analysis to include short bunch lengths (as compared to the beam pipe dimensions) and find that there is no longer the cancellation for forces both transverse to and in the direction of motion. We provide an estimate for the emittance growth as a function of bend angle, beam radius, and current, and for magnetic compression of an electron bunch

  17. Analysis of white noise excited elasto-plastic oscillator of several degrees of freedom

    DEFF Research Database (Denmark)

    Randrup-Thomsen, Søren

    1997-01-01

    The response of the white noise excited multi-degree-of-freedom (MDOF) oscillator has been analyzed in order to describe the plastic displacements of the relative response. Three different types of structural systems have been considered. The first type is a shear-wall frame having elastic......-ideal plastic stiffness properties of the columns connecting the two top-most floors. The second type is a shear-wall frame having elastic-ideal plastic stiffness properties of all columns, while the third type is a single-degree-of-freedom (SDOF) oscillator excited by horizontal and vertical white noise ground...

  18. Analysis of plastic residues in maple sap and syrup collected from tubing systems sanitized with isopropyl alcohol

    Directory of Open Access Journals (Sweden)

    Luc Lagacé

    2017-05-01

    Full Text Available A plastic tubing system operated under vacuum is usually used to collect sap from maple trees during spring time to produce maple syrup. This system is commonly sanitized with isopropyl alcohol (IPA to remove microbial contamination colonizing the system during the sugar season. Questions have been raised whether IPA would contribute to the leaching of plastic residues in maple sap and syrup coming from sanitized systems. First, an extraction experiment was performed in the lab on commercial plastic tubing materials that were submitted to IPA under harsh conditions. The results of the GC-MS analysis revealed the presence of many compounds that served has target for further tests. Secondly, tests were done on early and mid-season maple sap and syrup coming from many sugarbushes using IPA or not to determine potential concentrations of plastic residues. Results obtained from sap and syrup samples showed that no quantifiable (< 1–75 μg/L concentration of any plastic molecules tested was determined in all samples coming from IPA treated or not treated systems. However, some samples of first sap run used as a rinse solution to be discarded before the season start and that were coming from non sanitized or IPA sanitized systems, showed quantifiable concentrations of chemical residue such as ultraviolet protector (octabenzone. These results show that IPA can be safely used to sanitize maple sap collection system in regards to the leaching of plastic residues in maple sap and syrup and reinforced the need to thoroughly rinse the tubing system at the beginning of the season for both sanitized and non sanitized systems. Keywords: Food science, Food safety, Materials chemistry

  19. An analysis of the composition and metal contamination of plastics from waste electrical and electronic equipment (WEEE)

    Energy Technology Data Exchange (ETDEWEB)

    Stenvall, Erik, E-mail: erik.stenvall@chalmers.se [Department of Materials and Manufacturing Technology, Chalmers University of Technology, 41296 Göteborg (Sweden); Tostar, Sandra [Department of Industrial Materials Recycling, Chalmers University of Technology, 41296 Göteborg (Sweden); Boldizar, Antal [Department of Materials and Manufacturing Technology, Chalmers University of Technology, 41296 Göteborg (Sweden); Foreman, Mark R.StJ. [Department of Industrial Materials Recycling, Chalmers University of Technology, 41296 Göteborg (Sweden); Möller, Kenneth [Chemistry and Materials Technology, SP, 50115 Borås (Sweden)

    2013-04-15

    The compositions of three WEEE plastic batches of different origin were investigated using infrared spectroscopy, and the metal content was determined with inductively coupled plasma. The composition analysis of the plastics was based mainly on 14 samples collected from a real waste stream, and showed that the major constituents were high impact polystyrene (42 wt%), acrylonitrile–butadiene–styrene copolymer (38 wt%) and polypropylene (10 wt%). Their respective standard deviations were 21.4%, 16.5% and 60.7%, indicating a considerable variation even within a single batch. The level of metal particle contamination was found to be low in all samples, whereas wood contamination and rubber contamination were found to be about 1 wt% each in most samples. In the metal content analysis, iron was detected at levels up to 700 ppm in the recyclable waste plastics fraction, which is of concern due to its potential to catalyse redox reactions during melt processing and thus accelerate the degradation of plastics during recycling. Toxic metals were found only at very low concentrations, with the exception of lead and cadmium which could be detected at 200 ppm and 70 ppm levels, respectively, but these values are below the current threshold limits of 1000 ppm and 100 ppm set by the Restriction of Hazardous Substances directive.

  20. An analysis of the composition and metal contamination of plastics from waste electrical and electronic equipment (WEEE)

    International Nuclear Information System (INIS)

    Stenvall, Erik; Tostar, Sandra; Boldizar, Antal; Foreman, Mark R.StJ.; Möller, Kenneth

    2013-01-01

    The compositions of three WEEE plastic batches of different origin were investigated using infrared spectroscopy, and the metal content was determined with inductively coupled plasma. The composition analysis of the plastics was based mainly on 14 samples collected from a real waste stream, and showed that the major constituents were high impact polystyrene (42 wt%), acrylonitrile–butadiene–styrene copolymer (38 wt%) and polypropylene (10 wt%). Their respective standard deviations were 21.4%, 16.5% and 60.7%, indicating a considerable variation even within a single batch. The level of metal particle contamination was found to be low in all samples, whereas wood contamination and rubber contamination were found to be about 1 wt% each in most samples. In the metal content analysis, iron was detected at levels up to 700 ppm in the recyclable waste plastics fraction, which is of concern due to its potential to catalyse redox reactions during melt processing and thus accelerate the degradation of plastics during recycling. Toxic metals were found only at very low concentrations, with the exception of lead and cadmium which could be detected at 200 ppm and 70 ppm levels, respectively, but these values are below the current threshold limits of 1000 ppm and 100 ppm set by the Restriction of Hazardous Substances directive

  1. An analysis of the composition and metal contamination of plastics from waste electrical and electronic equipment (WEEE).

    Science.gov (United States)

    Stenvall, Erik; Tostar, Sandra; Boldizar, Antal; Foreman, Mark R StJ; Möller, Kenneth

    2013-04-01

    The compositions of three WEEE plastic batches of different origin were investigated using infrared spectroscopy, and the metal content was determined with inductively coupled plasma. The composition analysis of the plastics was based mainly on 14 samples collected from a real waste stream, and showed that the major constituents were high impact polystyrene (42 wt%), acrylonitrile-butadiene-styrene copolymer (38 wt%) and polypropylene (10 wt%). Their respective standard deviations were 21.4%, 16.5% and 60.7%, indicating a considerable variation even within a single batch. The level of metal particle contamination was found to be low in all samples, whereas wood contamination and rubber contamination were found to be about 1 wt% each in most samples. In the metal content analysis, iron was detected at levels up to 700 ppm in the recyclable waste plastics fraction, which is of concern due to its potential to catalyse redox reactions during melt processing and thus accelerate the degradation of plastics during recycling. Toxic metals were found only at very low concentrations, with the exception of lead and cadmium which could be detected at 200 ppm and 70 ppm levels, respectively, but these values are below the current threshold limits of 1000 ppm and 100 ppm set by the Restriction of Hazardous Substances directive. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. A calculational round robin in elastic-plastic fracture mechanics

    International Nuclear Information System (INIS)

    Larsson, L.H.

    1983-01-01

    Eighteen organisations participated in this elastic-plastic fracture mechanics (EPFM) numerical analysis round robin which treated the same three-point bend problem as a similar round robin conducted by ASTM four years earlier. The work involved the calculation of overall deformation, J, CTOD and crack profile using plane strain elastic-plastic finite element analysis for a monotonically increasing load up to a maximum deformation which was far beyond the elastic regime. It was found that all of the elastic solutions were accurate to within a few per cent. In the elastic-plastic regime, however, there was a large scatter of the results, increasing with increasing plastic deformation and roughly of the same order as in the ASTM round robin which contained ten solutions. No significant progress has taken place in the state of the art of numerical EPFM analysis over the four-year interval. The reasons for this scatter and tentative conclusions on the most suitable numerical analysis methods in EPFM are discussed. (author)

  3. Limited Associations between Keel Bone Damage and Bone Properties Measured with Computer Tomography, Three-Point Bending Test, and Analysis of Minerals in Swiss Laying Hens

    Directory of Open Access Journals (Sweden)

    Sabine G. Gebhardt-Henrich

    2017-08-01

    Full Text Available Keel bone damage is a wide-spread welfare problem in laying hens. It is unclear so far whether bone quality relates to keel bone damage. The goal of the present study was to detect possible associations between keel bone damage and bone properties of intact and damaged keel bones and of tibias in end-of-lay hens raised in loose housing systems. Bones were palpated and examined by peripheral quantitative computer tomography (PQCT, a three-point bending test, and analyses of bone ash. Contrary to our expectations, PQCT revealed higher cortical and trabecular contents in fractured than in intact keel bones. This might be due to structural bone repair after fractures. Density measurements of cortical and trabecular tissues of keel bones did not differ between individuals with and without fractures. In the three-point bending test of the tibias, ultimate shear strength was significantly higher in birds with intact vs. fractured keel bones. Likewise, birds with intact or slightly deviated keel bones had higher mineral and calcium contents of the keel bone than birds with fractured keel bones. Calcium content in keel bones was correlated with calcium content in tibias. Although there were some associations between bone traits related to bone strength and keel bone damage, other factors such as stochastic events related to housing such as falls and collisions seem to be at least as important for the prevalence of keel bone damage.

  4. The best marketing strategy in aesthetic plastic surgery: evaluating patients' preferences by conjoint analysis.

    Science.gov (United States)

    Marsidi, Nick; van den Bergh, Maurice W H M; Luijendijk, Roland W

    2014-01-01

    To provide the best marketing strategy for a private clinic, knowledge of patients' preferences is essential. In marketing, conjoint analysis has been frequently used to calculate which attributes of a product are most valuable to consumers. This study investigates the relative importance of attributes that influence the selection and decision-making process when choosing an aesthetic private clinic, using conjoint analysis. The following attributes were chosen by the senior author (R.W.L.) and a marketing and communications director after a preselection of 25 randomly selected people: relative cost of the procedure, travel time, experience of the plastic surgeon, size of the clinic, method of referral, and online presentation. The attributes were then divided into levels. Using a random factor conducted by SPSS, 18 different scenarios were created and rated online by 150 potential patients before their potential visit or consultation. The patients could rate these scenarios on a scale from 1 to 7 with respect to the likeliness of visiting the clinic. The most important attribute was experience of the surgeon (35.6 percent), followed by method of referral (21.5 percent), travel time (14.2 percent), cost of procedure (12.9 percent), online presentation (9.7 percent), and size of the clinic (6.1 percent). Six of 16 levels gave a negative influence on the decision making. The authors' study shows that the two most important attributes are the experience of the surgeon and the method of referral and that conjoint analysis is effective in determining patients' preferences. It also shows which levels positively or negatively contribute per attribute.

  5. Lateralization of the Avian Magnetic Compass: Analysis of Its Early Plasticity

    Directory of Open Access Journals (Sweden)

    Dennis Gehring

    2017-05-01

    Full Text Available In European Robins, Erithacus rubecula, the magnetic compass is lateralized in favor of the right eye/left hemisphere of the brain. This lateralization develops during the first winter and initially shows a great plasticity. During the first spring migration, it can be temporarily removed by covering the right eye. In the present paper, we used the migratory orientation of robins to analyze the circumstances under which the lateralization can be undone. Already a period of 1½ h being monocularly left-eyed before tests began proved sufficient to restore the ability to use the left eye for orientation, but this effect was rather short-lived, as lateralization recurred again within the next 1½ h. Interpretable magnetic information mediated by the left eye was necessary for removing the lateralization. In addition, monocularly, the left eye seeing robins could adjust to magnetic intensities outside the normal functional window, but this ability was not transferred to the “right-eye system”. Our results make it clear that asymmetry of magnetic compass perception is amenable to short-term changes, depending on lateralized stimulation. This could mean that the left hemispheric dominance for the analysis of magnetic compass information depends on lateralized interhemispheric interactions that in young birds can swiftly be altered by environmental effects.

  6. Stochastic higher order finite element elasto-plastic analysis of the necking phenomenon

    Directory of Open Access Journals (Sweden)

    Strąkowski Michał

    2017-01-01

    Full Text Available The principal goal of this work is to investigate an application of the stochastic perturbation technique of the 10th order in coupled thermo-elasto-plastic analysis of tension of the steel elastic bar exposed to fire with thermally dependent material characteristics. An ambient temperature, calculated from the fire curve after ISO 834-1, equivalent to the fire exposure of the steel structure is treated here as the input Gaussian random variable. It is uniquely defined by the constant mean value at outer surfaces of this element, where material parameters of the steel as Young modulus, yield strength, heat conductivity, capacity and thermal elongation are considered all as highly temperature-dependent. Computational implementation known as the Stochastic Finite Element Method is carried out with the use of the FEM system ABAQUS and computer algebra system MAPLE. It uses both polynomial and non-polynomial local response functions of stresses and displacements. The basic probabilistic characteristics of time-dependent structural response are determined (expectations, coefficients of variation, skewness and kurtosis and verified with classical Monte-Carlo simulation scheme and semi-analytical technique for input coefficient of variation not larger than 0.20. Finally, probabilistic convergence of all three methods versus increasing input uncertainty level is investigated.

  7. IR thermographic observation and shear bands plasticity analysis in Fe-based metallic glass

    International Nuclear Information System (INIS)

    Bouzakher, B.; Benameur, T.; Sidhom, H.

    2009-01-01

    Infrared thermography observation and in situ atomic force microscopy characterization were carried out to investigate the mechanical damage processes at the edge-notch region of large ribbons of Fe 78 Si 10 B 12 metallic glass. An obvious thermoelastic and inelastic degradation phenomenon was observed ahead at the notched region of the specimens, which probably result from free volume accumulation process and shear band activity during plane stress solicitations. Moreover, AFM topographic and frictional analysis of changes in the crack path during stable crack propagation regime revealed a periodic morphology evolution, formation of nanoscale damage cavity in the range of 20-140 nm and a maximum temperature rise ahead of the pre-crack tip was found in the order of 1.5 deg. C. The nanometer scaled shear offset, discreteness and shear bands density were determined. While these key parameters play a role in observing a large plastic zone in front of the crack, however they are unable to explain the distinct intrinsic ductility of some monolithic metallic glasses. A general Mohr-Coulomb-type constitutive description was used to deduce analytic expressions for prediction of the variation of hydrostatic component of the applied stress to the shear stress ratio as function of Poisson's ratio.

  8. Analysis of mean lifetime for capture of neutrons in boron-loaded plastic scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Kamykowski, E.A. (Grumman Corp., Bethpage, NY (USA). Research Center)

    1990-12-20

    The commercial availabiltiy of boron-loaded organic scintillators has led to the development of neutron detectors that operate as ''electronically'' black, totally absorbing spectrometers. The key to the enhanced spectroscopy is the delayed capture of nearly thermalized neutrons by {sup 10}B that can occur within a few microseconds after the energy pulse from prompt proton recoils. Accurate information regarding the mean lifetime is important for correct setting of the timing logic of the detection system to obtain good neutron detection efficiency with a low chance coincidence rate. In this paper we present an analysis of the mean lifetime for neutron capture for the boron-loaded plastic BC454. Measurements of the capture time constant obtained with a 7.62 cm diameter, 10.16 cm long detector are compared with values computed with the time-dependent Monte Carlo neutron transport code MCNP. Additional analyses using MCNP examine the dependence of the mean lifetime on the boron concentration, the detector's dimensions and the incident neutron energy. (orig.).

  9. Magnetically Assisted Bilayer Composites for Soft Bending Actuators

    Directory of Open Access Journals (Sweden)

    Sung-Hwan Jang

    2017-06-01

    Full Text Available This article presents a soft pneumatic bending actuator using a magnetically assisted bilayer composite composed of silicone polymer and ferromagnetic particles. Bilayer composites were fabricated by mixing ferromagnetic particles to a prepolymer state of silicone in a mold and asymmetrically distributed them by applying a strong non-uniform magnetic field to one side of the mold during the curing process. The biased magnetic field induces sedimentation of the ferromagnetic particles toward one side of the structure. The nonhomogeneous distribution of the particles induces bending of the structure when inflated, as a result of asymmetric stiffness of the composite. The bilayer composites were then characterized with a scanning electron microscopy and thermogravimetric analysis. The bending performance and the axial expansion of the actuator were discussed for manipulation applications in soft robotics and bioengineering. The magnetically assisted manufacturing process for the soft bending actuator is a promising technique for various applications in soft robotics.

  10. Magnetically Assisted Bilayer Composites for Soft Bending Actuators.

    Science.gov (United States)

    Jang, Sung-Hwan; Na, Seon-Hong; Park, Yong-Lae

    2017-06-12

    This article presents a soft pneumatic bending actuator using a magnetically assisted bilayer composite composed of silicone polymer and ferromagnetic particles. Bilayer composites were fabricated by mixing ferromagnetic particles to a prepolymer state of silicone in a mold and asymmetrically distributed them by applying a strong non-uniform magnetic field to one side of the mold during the curing process. The biased magnetic field induces sedimentation of the ferromagnetic particles toward one side of the structure. The nonhomogeneous distribution of the particles induces bending of the structure when inflated, as a result of asymmetric stiffness of the composite. The bilayer composites were then characterized with a scanning electron microscopy and thermogravimetric analysis. The bending performance and the axial expansion of the actuator were discussed for manipulation applications in soft robotics and bioengineering. The magnetically assisted manufacturing process for the soft bending actuator is a promising technique for various applications in soft robotics.

  11. [Is the use of plastic capillary tubes justified for blood gases analysis?].

    Science.gov (United States)

    Daurès, Marie-Françoise; Bozonnat, Marie-Cécile; Cristol, Jean-Paul

    2011-01-01

    Some clinical units, such as neonatal or maternity units, preferentially use capillary tubes when analysing blood gases. Using glass tubes is delicate and nurses must recollect blood when breaking. In order to eliminate this problem, we tested flexible, plastic capillary tubes in both the above mentionned units and in our biochemistry laboratory. Each unit, where glass tubes were habitually used, tested 200 flexible, plastic capillary tubes. In addition, the nursing staffed filled out a questionnaire concerned tube usage. Both units clearly preferred using the flexible tubes. In the laboratory, results for blood gas analyses were compared between rigid glass and flexible plastic capillary tubes for 112 patients. Concordance tests did not showed significant differences between the two tube types, except for hematocrit and total haemoglobin. A questionnaire was also presented to the lab technician, who confirmed the easier usability of plastic capillary tubes.

  12. A new approach for elasto-plastic finite strain analysis of cantilever ...

    Indian Academy of Sciences (India)

    GЦKHAN T TAYYAR

    mental kinematic theories are not well selected according to the expected deflection. ... elasto-plastic behavior to curvature-based kinematic dis- placement theory (KDT) [11]. In KDT ..... transportation and exploitation of sea resources. London:.

  13. Plastic Surgery and the Breast: A Citation Analysis of the Literature

    Directory of Open Access Journals (Sweden)

    Cormac W. Joyce, MB BCh

    2014-11-01

    Conclusions: This study has identified the most influential articles on breast in the plastic surgery literature over the past 68 years and highlighted many important scientific breakthroughs and landmarks that have occurred during this time.

  14. Elasto/visco-plastic analysis of moderately thick shells of revolution under asymmetrical loading

    International Nuclear Information System (INIS)

    Tao, K.; Takezono, S.

    1987-01-01

    In the present paper the analytical formulation for the elasto/visco-plastic problems of general, moderately thick shells of revolution subjected to asymmetrical loads is developed in consideration of the effect of shear deformation. The equations of equilibrium and the relations between the strains and displacements are derived by extending the Reissner-Naghdi theory (1941, 1957) for elastic shells with given consideration to the effect of shear deformation. As the constitutive relation, Hooke's law is used in the liner elastic range, and the elasto/visco-plastic equations by Perzyna (1966) are employed in the plastic range. The fundamental equations on the elasto/visco-plastic problems derived for incremental values are numerically solved by a finite difference method and the solutions are obtained by summation of the incremental values. (orig./GL)

  15. Taylor-plasticity-based analysis of length scale effects in void growth

    KAUST Repository

    Liu, Junxian; Demiral, Murat; El Sayed, Tamer S.

    2014-01-01

    plasticity as the flow rule, the critical cavitation condition, appearing when the derivative of the externally imposed mean stress with respect to the current void radius becomes zero, is rewritten analytically according to the Leibniz relation and found

  16. 3D finite element analysis on crack-tip plastic zone

    African Journals Online (AJOL)

    user

    International Journal of Engineering, Science and Technology ... directed in this investigation to achieve a few numerical estimations of 3D plastic zone shape ..... crack front, using domain integral method the software (ABAQUS) automatically.

  17. Industry Financial Relationships in Plastic Surgery: Analysis of the Sunshine Act Open Payments Database.

    Science.gov (United States)

    Chao, Albert H; Gangopadhyay, Noopur

    2016-08-01

    Limited data exist regarding industry financial relationships in plastic surgery. The Sunshine Act Open Payments Database currently represents the largest repository of these data, but is limited primarily to queries of individual providers. The purpose of this study was to analyze these data and present them in a manner that better delineates these relationships, and to compare plastic surgery with other surgical subspecialties. A review of the Open Payments Database was performed for the period from January 1, 2014, to December 31, 2014. These data were analyzed with respect to types of payments, characteristics of plastic surgeons and companies, and comparison with other surgical subspecialties. A total of 49,053 payments from 274 companies were identified that were made to 4812 plastic surgeons (475 academic and 4337 private practice). The total value of payments was $17,091,077. Food and beverage represented the most common type of payment (82.2 percent). Royalties and licensing represented the highest valued type of payment (35.7 percent), but were received by only a minority of plastic surgeons (0.5 percent). No significant differences were identified between academic and private practice plastic surgeons in the value or quantity of payments. Plastic surgery (54.5 percent) exhibited the lowest prevalence of industry financial relationships compared with otolaryngology (57.9 percent), orthopedics (62.4 percent), neurosurgery (87.8 percent), and urology (63.1 percent) (p < 0.001). Approximately half of all plastic surgeons have industry financial relationships. The prevalence of these relationships is comparatively less than in other surgical subspecialties.

  18. Discrete dislocation plasticity analysis of loading rate-dependent static friction.

    Science.gov (United States)

    Song, H; Deshpande, V S; Van der Giessen, E

    2016-08-01

    From a microscopic point of view, the frictional force associated with the relative sliding of rough surfaces originates from deformation of the material in contact, by adhesion in the contact interface or both. We know that plastic deformation at the size scale of micrometres is not only dependent on the size of the contact, but also on the rate of deformation. Moreover, depending on its physical origin, adhesion can also be size and rate dependent, albeit different from plasticity. We present a two-dimensional model that incorporates both discrete dislocation plasticity inside a face-centred cubic crystal and adhesion in the interface to understand the rate dependence of friction caused by micrometre-size asperities. The friction strength is the outcome of the competition between adhesion and discrete dislocation plasticity. As a function of contact size, the friction strength contains two plateaus: at small contact length [Formula: see text], the onset of sliding is fully controlled by adhesion while for large contact length [Formula: see text], the friction strength approaches the size-independent plastic shear yield strength. The transition regime at intermediate contact size is a result of partial de-cohesion and size-dependent dislocation plasticity, and is determined by dislocation properties, interfacial properties as well as by the loading rate.

  19. Determining the bio-based content of bio-plastics used in Thailand by radiocarbon analysis

    Science.gov (United States)

    Ploykrathok, T.; Chanyotha, S.

    2017-06-01

    Presently, there is an increased interest in the development of bio-plastic products from agricultural materials which are biodegradable in order to reduce the problem of waste disposal. Since the amount of modern carbon in bio-plastics can indicate how much the amount of agricultural materials are contained in the bio-plastic products, this research aims to determine the modern carbon in bio-plastic using the carbon dioxide absorption method. The radioactivity of carbon-14 contained in the sample is measured by liquid scintillation counter (Tri-carb 3110 TR, PerkinElmer). The percentages of bio-based content in the samples were determined by comparing the observed modern carbon content with the values contained in agricultural raw materials. The experimental results show that only poly(lactic acid) samples have the modern carbon content of 97.4%, which is close to the agricultural materials while other bio-plastics types are found to have less than 50% of the modern carbon content. In other words, most of these bio-plastic samples were mixed with other materials which are not agriculturally originated.

  20. Determining the bio-based content of bio-plastics used in Thailand by radiocarbon analysis

    International Nuclear Information System (INIS)

    Ploykrathok, T; Chanyotha, S

    2017-01-01

    Presently, there is an increased interest in the development of bio-plastic products from agricultural materials which are biodegradable in order to reduce the problem of waste disposal. Since the amount of modern carbon in bio-plastics can indicate how much the amount of agricultural materials are contained in the bio-plastic products, this research aims to determine the modern carbon in bio-plastic using the carbon dioxide absorption method. The radioactivity of carbon-14 contained in the sample is measured by liquid scintillation counter (Tri-carb 3110 TR, PerkinElmer). The percentages of bio-based content in the samples were determined by comparing the observed modern carbon content with the values contained in agricultural raw materials. The experimental results show that only poly(lactic acid) samples have the modern carbon content of 97.4%, which is close to the agricultural materials while other bio-plastics types are found to have less than 50% of the modern carbon content. In other words, most of these bio-plastic samples were mixed with other materials which are not agriculturally originated. (paper)

  1. COMPARATIVE ANALYSIS OF PLASTIC ATTRIBUTES OF DIFFERENT CARP KOI FORMS (CYPRINUS CARPIO KOI

    Directory of Open Access Journals (Sweden)

    O. O. Lysak

    2014-08-01

    variances of morphometric indexes of fish from different groups is mathematically approved by Student’s index-criterion. Variances were considered to be valid if Student’s criterion exceeded 2, 68 at insurance level of magnitude α = 0,01 that is accepted as an ample for majority of biological objects. By comparison of different carp koi (Cyprinus carpio koi forms researchers used Mayr’s coefficient of resolution. (CD. It is evident that the less curves of two compared populations are lapped over, the more difference is between middle М1 and М2 divided by sum of middle quadric deviations σ1 і σ2. Coefficient of directive deviation (Кdv characterizes percentage deviation of two compared indexes of particular attribute. For deviation determination (Кdv between the index, the difference between an attribute A and the same attribute of sample index E is necessary to divide by index of attribute E and multiply by 100%.Estimation criterion is the same as in variability index – low level of deviation Кdv ≤ 5%, middle Кdv  = 10-30%, large Кdv > 30-50%. At conducting the morphological analysis of groups №I-IV of carp koi different forms authors researched 30 plastic attributes. Plastic attributes were grouped according to indexes which were determined by percents from zoological length of the body ( standard length, trunk length, the biggest and smallest heights, antidorsal and postdorsal distances, length of tail-stem, antipectoral, antiventral, antianal pectroventral, ventroanal distances and length of a head; were determined by percents from length of a head ( length of a fish snout, eye diameter, sight unseen distance, height and width of forehead, lengths of lower and upper jaw, height of the head near the nape and through the middle of the eye but the measuring of all the fins were held separately so as for koi they are the criterion for estimation of form quality, which also were determined by percents from body length ( the biggest height and length of

  2. Finite element elasto-plastic analysis of thin walled structures of reinforced concrete as applied to reactor facilities

    International Nuclear Information System (INIS)

    Fujita, F.; Tsuboi, Y.

    1981-01-01

    The authors developed a new program of elasto-plastic analysis of reinforced concrete shells, in which the simplest model of shell element and an orthotropic constitutive relation are adopted, and verified its validity with reference to the results of model experiments of containers and box-wall structures with various loading conditions. For the two-dimensional stress-strain relationship of concrete, an orthotropic nonlinear formula proposed by one of the authors was adopted. For concrete, the octahedral shear failure and tension cut-off criteria were also imposed. The Kirchhoff-Love's assumptions were assumed to be valid for the whole range of the analysis and the layered approach of elasto-plastic stiffness evaluation. Derivation of the shell element is outlined with examination of its accuracy in elastic range and the assumption of elasto-plastic material property and the procedure of nonlinear analysis are described. As examples, the method is applied to the analysis of a cylindrical container and a box-wall structure. Comparison of the computed results with the corresponding experimental data indicates the applicability of the proposed method. (orig./HP)

  3. Comparison Between Stress Obtained by Numerical Analysis and In-Situ Measurements on a Flexible Pipe Subjected to In-Plane Bending Test

    DEFF Research Database (Denmark)

    Vestergaard Lukassen, Troels; Glejbøl, Kristian; Lyckegaard, Anders

    2016-01-01

    to stress patterns obtained during in-situ OMS measurements carried out during an actual experimental inplane bending test. The study showed a good correlation between the stress variation predicted with the finite element model and the measured stress variation.......To predict the lifetime and long-term properties of tensile armour wires in a dynamically loaded pipe, it is essential to have a tool which allows detailed prediction of the stress variations in the tensile armour wires during global pipe loading. Furthermore, detailed understanding of the stress...... variations will allow for performance optimization of the armour layers. To study the detailed stress variations in flexible pipes during dynamic loading, a comprehensive three-dimensional implicit nonlinear finite element model has been developed. The predicted numerical stress variations will be compared...

  4. The effect of cracks on the limit load of pipe bends under in-plane bending

    International Nuclear Information System (INIS)

    Griffiths, J.E.

    1976-06-01

    The limit analysis of the in-plane bending of curved tubes had received attention previously, but the effect of defects in the tube has not been considered. A lower bound has been established which, with no defects present, is in agreement with previous theoretical work. The method of linear programming allows cracks to be introduced into analysis, and results have been obtained for various geometries of defect. The results show that the presence of cracks in the pipe bend can have a marked effect on the theoretical limit load: a part-through crack penetrating only half the wall thickness will reduce the limit moment by up to 10%. The worst possible case of a through-crack may reduce the limit load by 60%. (author)

  5. The effect of cracks on the limit load of pipe bends under in-plane bending

    International Nuclear Information System (INIS)

    Griffiths, J.E.

    1976-06-01

    The limit analysis of the in-plane bending of curved tubes had received attention previously, but the effect of defects in the tube has not been considered. A lower bound is established, which, with no defects present, is in agreement with previous theoretical work. The method of linear programming allows cracks to be introduced into the analysis. and results have been obtained for various geometries of defect. The results show that the presence of cracks in the pipe bend can have a marked effect on the theoretical limit load: a part-through crack penetrating only half the wall thickness will reduce the limit moment by up to 10%. The worst possible case of a through-crack may reduce the limit load by 60% (author)

  6. 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.

  7. Texture analysis with neutron bending on geological/mineralogical multi-phase samples using a locally resolving detector and profile analysis

    International Nuclear Information System (INIS)

    Merz, P.L.

    1991-02-01

    In the context of this work, the NANCY four circuit diffractometer of the University of Bonn at the RRJ2 research reactor at KFA Juelich was equipped with a linear locally resolving scintillation detector JULIOS. To evaluate the diffractogram occurring at a pole figure measurement, user-friendly profile analysis and other evaluation programs were developed on the PC. The course of evaluation was largely automated, so that only a few interactive steps are required. The measuring period of a sample is usually two to three days. Up to 35 pole figures are produced, depending on the phase conditions of the examined sample. The evaluation of up to 900 diffractograms with the aid of the automatically running profile analysis program takes between 30 and 100 minutes on a 20 MHz PC 386. Pole figure datafiles are produced from the intensity data obtained in this way by a conversion program. The texture analyses of copper pyrites ores introduced here are connected with geological questions. (orig.) [de

  8. Mass spectrometry analysis of etch products from CR-39 plastic irradiated by heavy ions

    Science.gov (United States)

    Kodaira, S.; Nanjo, D.; Kawashima, H.; Yasuda, N.; Konishi, T.; Kurano, M.; Kitamura, H.; Uchihori, Y.; Naka, S.; Ota, S.; Ideguchi, Y.; Hasebe, N.; Mori, Y.; Yamauchi, T.

    2012-09-01

    As a feasibility study, gas chromatography-mass spectrometry (GC-MS) and matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) have been applied to analyze etch products of CR-39 plastic (one of the most frequently used solid states nuclear track detector) for the understanding of track formation and etching mechanisms by heavy ion irradiation. The etch products of irradiated CR-39 dissolved in sodium hydroxide solution (NaOH) contain radiation-induced fragments. For the GC-MS analysis, we found peaks of diethylene glycol (DEG) and a small but a definitive peak of ethylene glycol (EG) in the etch products from CR-39 irradiated by 60 MeV N ion beams. The etch products of unirradiated CR-39 showed a clear peak of DEG, but no other significant peaks were found. DEG is known to be released from the CR-39 molecule as a fragment by alkaline hydrolysis reaction of the polymer. We postulate that EG was formed as a result of the breaking of the ether bond (C-O-C) of the DEG part of the CR-39 polymer by the irradiation. The mass distribution of polyallylalcohol was obtained from the etch products from irradiated and unirradiated CR-39 samples by MALDI-MS analysis. Polyallylalcohol, with the repeating mass interval of m/z = 58 Da (dalton) between m/z = 800 and 3500, was expected to be produced from CR-39 by alkaline hydrolysis. We used IAA as a matrix to assist the ionization of organic analyte in MALDI-MS analysis and found that peaks from IAA covered mass spectrum in the lower m/z region making difficult to identify CR-39 fragment peaks which were also be seen in the same region. The mass spectrometry analysis using GC-MS and MALDI-MS will be powerful tools to investigate the radiation-induced polymeric fragments and helping to understand the track formation mechanism in CR-39 by heavy ions.

  9. Analysis of trophic interactions reveals highly plastic response to climate change in a tri-trophic High-Arctic ecosystem

    DEFF Research Database (Denmark)

    Mortensen, Lars O.; Schmidt, Niels Martin; Hoye, Toke T.

    2016-01-01

    As a response to current climate changes, individual species have changed various biological traits, illustrating an inherent phenotypic plasticity. However, as species are embedded in an ecological network characterised by multiple consumer-resource interactions, ecological mismatches are likely...... to arise when interacting species do not respond homogeneously. The approach of biological networks analysis calls for the use of structural equation modelling (SEM), a multidimensional analytical setup that has proven particularly useful for analysing multiple interactions across trophic levels. Here we...

  10. Determination of mercury in discharge water from plastic manufactory by neutron activation analysis and copper powder adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Houng-Huei, L [National Tsing Hua University Hsinchu, Taiwan (Republic of China)

    1979-02-28

    Through copper powder adsorption, neutron activation analysis was used to determine the mercury in discharge water from a plastic manufactory where the water samples were taken from various discharge ditches. The experimental results showed that waste water from mercury cells contained 1.7x10/sup -9/ approximately 8.19x10/sup -6/ g Hg/ml while water samples taken from other areas did not show significant mercury level and were below the limit of detection.

  11. Automated analysis of damages for radiation in plastics surfaces; Analisis automatizado de danos por radiacion en superficies plasticas

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, C; Camacho M, E; Tavera, L; Balcazar, M [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1990-02-15

    Analysis of damages done by the radiation in a polymer characterized by optic properties of polished surfaces, of uniformity and chemical resistance that the acrylic; resistant until the 150 centigrade grades of temperature, and with an approximate weight of half of the glass. An objective of this work is the development of a method that analyze in automated form the superficial damages induced by radiation in plastic materials means an images analyst. (Author)

  12. Structural evaluation method for class 1 vessels by using elastic-plastic finite element analysis in code case of JSME rules on design and construction

    International Nuclear Information System (INIS)

    Asada, Seiji; Hirano, Takashi; Nagata, Tetsuya; Kasahara, Naoto

    2008-01-01

    A structural evaluation method by using elastic-plastic finite element analysis has been developed and published as a code case of Rules on Design and Construction for Nuclear Power Plants (The First Part: Light Water Reactor Structural Design Standard) in the JSME Codes for Nuclear Power Generation Facilities. Its title is 'Alternative Structural Evaluation Criteria for Class 1 Vessels Based on Elastic-Plastic Finite Element Analysis' (NC-CC-005). This code case applies elastic-plastic analysis to evaluation of such failure modes as plastic collapse, thermal ratchet, fatigue and so on. Advantage of this evaluation method is free from stress classification, consistently use of Mises stress and applicability to complex 3-dimensional structures which are hard to be treated by the conventional stress classification method. The evaluation method for plastic collapse has such variation as the Lower Bound Approach Method, Twice-Elastic-Slope Method and Elastic Compensation Method. Cyclic Yield Area (CYA) based on elastic analysis is applied to screening evaluation of thermal ratchet instead of secondary stress evaluation, and elastic-plastic analysis is performed when the CYA screening criteria is not satisfied. Strain concentration factors can be directly calculated based on elastic-plastic analysis. (author)

  13. Study of laser bending of a preloaded Titanium alloy sheet

    Directory of Open Access Journals (Sweden)

    Wang Xiufeng

    2014-01-01

    Full Text Available Laser bending of sheet metals with preload offers some attractive characteristics/merits, comparing to laser free bending without prestressing on the metals. The study reported in this paper was focused on a Titanium alloy which finds widespread applications in aerospace manufacturing. FE simulation of laser bending with prestressing on the Titanium alloy sheet was conducted for the analysis of the bending process and experiment carried out to verify the model and the result. It was shown that the simulation result is close to that measured in the experiment. Based on the computed result, the load-displacement curve was analysed and transmission efficiency of the elastic energy defined to evaluate the bending effect. These enhanced understanding of the mechanism of laser bending with a preload. A method for the optimization on technological parameters was further proposed. Referring to the deformation targeted, the preload value was determined through the FE simulation. The result showed that, on the premise that the specimen surface can be prevented from damaging, transmission efficiency of the elastic energy could reach to the maximum value through adjusting technological parameters of the laser system and deformation accuracy of the specimen could also be improved through this approach. The work presented in this paper may find its application in the manufacture of Titanium alloy sheets with a more cost-effective and a more precise way.

  14. Tunable characteristics of bending resonance frequency in magnetoelectric laminated composites

    Institute of Scientific and Technical Information of China (English)

    Chen Lei; Li Ping; Wen Yu-Mei; Zhu Yong

    2013-01-01

    As the magnetoelectric (ME) effect in piezoelectric/magnetostrictive laminated composites is mediated by mechanical deformation,the ME effect is significantly enhanced in the vicinity of resonance frequency.The bending resonance frequency (fr) of bilayered Terfenol-D/PZT (MP) laminated composites is studied,and our analysis predicts that (i) the bending resonance frequency of an MP laminated composite can be tuned by an applied dc magnetic bias (Hdc) due to the △E effect; (ii) the bending resonance frequency of the MP laminated composite can be controlled by incorporating FeCuNbSiB layers with different thicknesses.The experimental results show that with Hdc increasing from 0Oe (1 Oe=79.5775 A/m)to 700 Oe,the bending resonance frequency can be shifted in a range of 32.68 kHz ≤ fr ≤ 33.96 kHz.In addition,with the thickness of the FeCuNbSiB layer increasing from 0 μm to 90 μm,the bending resonance frequency of the MP laminated composite gradually increases from 33.66 kHz to 39.18 kHz.This study offers a method of adjusting the strength of dc magnetic bias or the thicknesses of the FeCuNbSiB layer to tune the bending resonance frequency for ME composite,which plays a guiding role in the ME composite design for real applications.

  15. Integrative Analysis of Disease Signatures Shows Inflammation Disrupts Juvenile Experience-Dependent Cortical Plasticity

    Science.gov (United States)

    Smith, Milo R.; Burman, Poromendro

    2016-01-01

    Throughout childhood and adolescence, periods of heightened neuroplasticity are critical for the development of healthy brain function and behavior. Given the high prevalence of neurodevelopmental disorders, such as autism, identifying disruptors of developmental plasticity represents an essential step for developing strategies for prevention and intervention. Applying a novel computational approach that systematically assessed connections between 436 transcriptional signatures of disease and multiple signatures of neuroplasticity, we identified inflammation as a common pathological process central to a diverse set of diseases predicted to dysregulate plasticity signatures. We tested the hypothesis that inflammation disrupts developmental cortical plasticity in vivo using the mouse ocular dominance model of experience-dependent plasticity in primary visual cortex. We found that the administration of systemic lipopolysaccharide suppressed plasticity during juvenile critical period with accompanying transcriptional changes in a particular set of molecular regulators within primary visual cortex. These findings suggest that inflammation may have unrecognized adverse consequences on the postnatal developmental trajectory and indicate that treating inflammation may reduce the burden of neurodevelopmental disorders. PMID:28101530

  16. Characteristic Analysis Light Intensity Sensor Based On Plastic Optical Fiber At Various Configuration

    Science.gov (United States)

    Arifin, A.; Lusiana; Yunus, Muhammad; Dewang, Syamsir

    2018-03-01

    This research discusses the light intensity sensor based on plastic optical fiber. This light intensity sensor is made of plastic optical fiber consisting of two types, namely which is cladding and without cladding. Plastic optical fiber used multi-mode step-index type made of polymethyl metacrylate (PMMA). The infrared LED emits light into the optical fiber of the plastic and is subsequently received by the phototransistor to be converted to an electric voltage. The sensor configuration is made with three models: straight configuration, U configuration and gamma configuration with cladding and without cladding. The measured light source uses a 30 Watt high power LED with a light intensity of 0 to 10 Klux. The measured light intensity will affect the propagation of light inside the optical fiber sensor. The greater the intensity of the measured light, the greater the output voltage that is read on the computer. The results showed that the best optical fiber sensor characteristics were obtained in U configuration. Sensors with U-configuration without cladding had the best sensitivity and resolution values of 0.0307 volts/Klux and 0.0326 Klux. The advantages of this measuring light intensity based on the plastic optical fiber instrument are simple, easy-to-make operational systems, low cost, high sensitivity and resolution.

  17. Analysis of the influencing factors of PAEs volatilization from typical plastic products.

    Science.gov (United States)

    Chen, Weidong; Chi, Chenchen; Zhou, Chen; Xia, Meng; Ronda, Cees; Shen, Xueyou

    2018-04-01

    The primary emphasis of this research was to investigate the foundations of phthalate (PAEs) pollutant source researches and then firstly confirmed the concept of the coefficient of volatile strength, namely phthalate total content in per unit mass and unit surface area of pollutant sources. Through surveying and evaluating the coefficient of volatile strength of PAEs from typical plastic products, this research carried out reasonable classification of PAEs pollutant sources into three categories and then investigated the relationship amongst the coefficient of volatile strength as well as other environmental factors and the concentration level of total PAEs in indoor air measured in environment chambers. Research obtained phthalate concentration results under different temperature, humidity, the coefficient of volatile strength and the closed time through the chamber experiment. In addition, this study further explored the correlation and ratio of influencing factors that affect the concentration level of total PAEs in environment chambers, including environmental factors, the coefficient of volatile strengths of PAEs and contents of total PAEs in plastic products. The research created an improved database system of phthalate the coefficient of volatile strengths of each type of plastic goods, and tentatively revealed that the volatile patterns of PAEs from different typical plastic goods, finally confirmed that the coefficient of volatile strengths of PAEs is a major factor that affects the indoor air total PAEs concentration, which laid a solid foundation for further establishing the volatile equation of PAEs from plastic products. Copyright © 2017. Published by Elsevier B.V.

  18. Extension versus Bending for Continuum Robots

    Directory of Open Access Journals (Sweden)

    George Grimes

    2008-11-01

    Full Text Available In this paper, we analyze the capabilities of a novel class of continuous-backbone ("continuum" robots. These robots are inspired by biological "trunks, and tentacles". However, the capabilities of established continuum robot designs, which feature controlled bending but not extension, fall short of those of their biological counterparts. In this paper, we argue that the addition of controlled extension provides dual and complementary functionality, and correspondingly enhanced performance, in continuum robots. We present an interval-based analysis to show how the inclusion of controllable extension significantly enhances the workspace and capabilities of continuum robots.

  19. Minimum emittance of three-bend achromats

    International Nuclear Information System (INIS)

    Li Xiaoyu; Xu Gang

    2012-01-01

    The calculation of the minimum emittance of three-bend achromats (TBAs) made by Mathematical software can ignore the actual magnets lattice in the matching condition of dispersion function in phase space. The minimum scaling factors of two kinds of widely used TBA lattices are obtained. Then the relationship between the lengths and the radii of the three dipoles in TBA is obtained and so is the minimum scaling factor, when the TBA lattice achieves its minimum emittance. The procedure of analysis and the results can be widely used in achromats lattices, because the calculation is not restricted by the actual lattice. (authors)

  20. Thermo-elastic-plastic analysis for elastic component under high temperature fatigue crack growth rate

    Science.gov (United States)

    Ali, Mohammed Ali Nasser

    The research project presents a fundamental understanding of the fatigue crack growth mechanisms of AISI 420 martensitic stainless steel, based on the comparison analysis between the theoretical and numerical modelling, incorporating research findings under isothermal fatigue loading for solid cylindrical specimen and the theoretical modelling with the numerical simulation for tubular specimen when subjected to cyclic mechanical loading superimposed by cyclic thermal shock.The experimental part of this research programme studied the fatigue stress-life data for three types of surface conditions specimen and the isothermal stress-controlled fatigue testing at 300 °C - 600 °C temperature range. It is observed that the highest strength is obtained for the polished specimen, while the machined specimen shows lower strength, and the lowest strength is the notched specimen due to the high effect of the stress concentration. The material behaviour at room and high temperatures shows an initial hardening, followed by slow extension until fully plastic saturation then followed by crack initiation and growth eventually reaching the failure of the specimen, resulting from the dynamic strain ageing occurred from the transformation of austenitic microstructure to martensite and also, the nucleation of precipitation at grain boundaries and the incremental temperature increase the fatigue crack growth rate with stress intensity factor however, the crack growth rate at 600 °C test temperature is less than 500 °C because of the creep-fatigue taking place.The theoretical modelling presents the crack growth analysis and stress and strain intensity factor approaches analysed in two case studies based on the addition of thermo-elastic-plastic stresses to the experimental fatigue applied loading. Case study one estimates the thermal stresses superimposed sinusoidal cyclic mechanical stress results in solid cylinder under isothermal fatigue simulation. Case study two estimates the

  1. Happy and Unhappy Patients: A Quantitative Analysis of Online Plastic Surgeon Reviews for Breast Augmentation.

    Science.gov (United States)

    Dorfman, Robert G; Purnell, Chad; Qiu, Cecil; Ellis, Marco F; Basu, C Bob; Kim, John Y S

    2018-05-01

    Online reviews have become modern versions of the word-of-mouth recommendation, and prospective patients are increasingly consulting them before making decisions about their surgical care. The authors' objectives were to (1) identify trends in the use of online reviews, and (2) important reasons for patient satisfaction and dissatisfaction with aesthetic surgery. The authors selected breast augmentation as the primary procedure of interest. Reviews of the top 10 to 20 most reviewed plastic surgeons in each of six large metropolitan areas were obtained from Google, Yelp, and RealSelf. Reviews were assessed for predefined dimensions of satisfaction and dissatisfaction. A total of 1077 breast augmentation reviews were obtained. Ratings were distributed bimodally, with peaks at five stars and one star. The majority of reviews were positive (87.5 percent). Relative popularity of Google versus Yelp varied across geographic regions, and average rating varied by platform. Between 2011 and 2016, the number of online reviews for breast augmentation grew at an average rate of 42.6 percent per year. Aesthetic outcome was the most commonly cited dimension (69.8 percent of reviews), whereas cost was mentioned in only 7.8 percent of reviews. A substantial minority of negative Yelp (37 percent) and Google (9.4 percent) reviews were written by patients who did not actually undergo surgery. Free-text analysis of heterogeneous reviews (containing positive and negative attributes) classified dimensions as critical, redeemable, or protective. As the influence of online review platforms continues to grow, understanding drivers of positive and negative reviews may help surgeons improve patient satisfaction.

  2. Three-dimensional elasto-plastic soil modelling and analysis of sauropod tracks

    Directory of Open Access Journals (Sweden)

    Eugenio Sanz

    2016-06-01

    Full Text Available This paper reports the use of FEA (Finite Element Analysis to model dinosaur tracks. Satisfactory reproductions of sauropod ichnites were simulated using 3D numerical models of the elasto-plastic behaviour of soils. Though the modelling was done of ichnites in situ at the Miraflores I tracksite (Soria, Spain, the methodology could be applied to other tracksites to improve their ichnological interpretation and better understand how the type and state of the trodden sediment at the moment the track is created is a fundamental determinant of the morphology of the ichnite. The results obtained explain why the initial and commonly adopted hypothesis—that soft sediments become progressively more rigid and resistant at depth—is not appropriate at this tracksite. We explain why it is essential to consider a more rigid superficial layer (caused by desiccation overlying a softer layer that is extruded to form a displacement rim. Adult sauropods left trackways behind them. These tracks could be filled up with water due to phreatic level was close to the ground surface. The simulation provides us with a means to explain the differences between similar tracks (of different depths; with or without displacement rims in the various stratigraphic layers of the tracksite and to explain why temporary and variable conditions of humidity lead to these differences in the tracks. The simulations also demonstrate that track depth alone is insufficient to differentiate true tracks from undertracks and that other discrimination criteria need to be taken into account. The scarcity of baby sauropod tracks is explained because they are shallow and easily eroded.

  3. 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

  4. Economic analysis of irrigated melon cultivated in greenhouse with and without soil plastic mulching

    Directory of Open Access Journals (Sweden)

    Elvis M. de C. Lima

    Full Text Available ABSTRACT The objective of this study was to analyze technically and economically the irrigated ‘Gália’ melon (Hybrid Nectar, cultivated in greenhouse with and without using plastic mulch covering on the soil. Simultaneously, two experiments were conducted using a completely randomized design (CRD, in which melon plants were submitted to five water availability levels, defined by 50, 75, 100, 125, and 150% of crop evapotranspiration, with four replicates. The difference between experiments were only about the soil covering with plastic mulch: with (CC or without (SC plastic mulch. The economically optimal irrigation depths were 208.83 and 186.88 mm, resulting in yields of 50.85 and 44.51 t ha-1 for the experiments with and without mulching, respectively. The results showing the economically optimal irrigation depths were very close to those that produced the highest yield.

  5. Analysis of Polyadipate Ester Content in PVC Plastics by Means of FT-Raman Spectroscopy

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2006-01-01

    Plasticizers are needed in flexible PVC (PolyVinylChloride) products. There is serious concern that commonly used phthalate esters may harm life reproduction systems. To avoid the problems, instead adipate di-esters (AEs) of C8 to C10 alcohols are used as higher prized alternatives; e.g. di-2......-ethylhexyl adipate or DEHA [103-23-1], also known as Adimoll or di-octyl adipate, DOA. A widely used plasticizer in food (cling) films is DEHA, often in combination with polymers, epoxidized soya-bean oil, etcetera. DEHA also occurs in children toys. We have previously shown that the presence of phthalate...... esters in PVC can be rapidly analyzed by Fourier transform (FT-) Raman spectroscopy excited with a 1064 nm laser. Here in this project we report a similar study. The aim was to find out whether FT-Raman spectroscopy can be used to determine the presence of adipate esters (AEs) as plasticizers...

  6. Multidimensional Analysis of Direct-Drive Plastic-Shell Implosions on OMEGA

    Science.gov (United States)

    Radha, P. B.

    2004-11-01

    Direct-drive implosions of plastic shells with the OMEGA laser are used as energy-scaled warm surrogates for ignition cryogenic targets designed for use on the National Ignition Facility. Plastic targets involve varying shell thickness (15 to 33 μm), fill pressures (3 to 15 atm), and shell adiabats. The multidimensional hydrodynamics code DRACO is used to evaluate the effects of capsule-surface roughness and illumination nonuniformities on target performance. These simulations indicate that shell stability during the acceleration phase plays a critical role in determining fusion yields. For shells that are thick enough to survive the Rayleigh--Taylor growth, target yields are significantly reduced by growth of the long (ℓ surrogacy between these plastic-shell implosions and the cryogenic ignition designs.

  7. Strain gradient crystal plasticity analysis of a single crystal containing a cylindrical void

    DEFF Research Database (Denmark)

    Borg, Ulrik; Kysar, J.W.

    2007-01-01

    to one another. Finite element simulations are performed using a strain gradient crystal plasticity formulation with an intrinsic length scale parameter in a non-local strain gradient constitutive framework. For a vanishing length scale parameter the non-local formulation reduces to a local crystal...... plasticity formulation. The stress and deformation fields obtained with a local non-hardening constitutive formulation are compared to those obtained from a local hardening formulation and to those from a non-local formulation. Compared to the case of the non-hardening local constitutive formulation......, it is shown that a local theory with hardening has only minor effects on the deformation field around the void, whereas a significant difference is obtained with the non-local constitutive relation. Finally, it is shown that the applied stress state required to activate plastic deformation at the void is up...

  8. Testing and Analysis of the First Plastic Melt Waste Compactor Prototype

    Science.gov (United States)

    Pace, Gregory S.; Fisher, John W.

    2005-01-01

    A half scale Plastic Melt Waste Compactor prototype has been developed at NASA Ames Research Center. The half scale prototype unit will lead to the development of a full scale Plastic Melt Waste Compactor prototype that is representative of flight hardware that would be used on near and far term space missions. This report details the testing being done on the prototype Plastic Melt Waste Compactor by the Solid Waste Management group at NASA Ames Research Center. The tests are designed to determine the prototype's functionality, simplicity of operation, ability to contain and control noxious off-gassing, biological stability of the processed waste, and water recovery potential using a waste composite that is representative of the types of wastes produced on the International Space Station, Space Shuttle, MIR and Skylab missions.

  9. Elasto-Plastic Stress Analysis in Rotating Disks and Pressure Vessels Made of Functionally Graded Materials

    Directory of Open Access Journals (Sweden)

    Amir T. Kalali

    Full Text Available Abstract A new elastio-plastic stress solution in axisymmetric problems (rotating disk, cylindrical and spherical vessel is presented. The rotating disk (cylindrical and spherical vessel was made of a ceramic/metal functionally graded material, i.e. a particle-reinforced composite. It was assumed that the material's plastic deformation follows an isotropic strain-hardening rule based on the von-Mises yield criterion. The mechanical properties of the graded material were modeled by the modified rule of mixtures. By assuming small strains, Hencky's stress-strain relation was used to obtain the governing differential equations for the plastic region. A numerical method for solving those differential equations was then proposed that enabled the prediction of stress state within the structure. Selected finite element results were also presented to establish supporting evidence for the validation of the proposed approach.

  10. Sensitivity analysis of limit state functions for probability-based plastic design

    Science.gov (United States)

    Frangopol, D. M.

    1984-01-01

    The evaluation of the total probability of a plastic collapse failure P sub f for a highly redundant structure of random interdependent plastic moments acted on by random interdepedent loads is a difficult and computationally very costly process. The evaluation of reasonable bounds to this probability requires the use of second moment algebra which involves man statistical parameters. A computer program which selects the best strategy for minimizing the interval between upper and lower bounds of P sub f is now in its final stage of development. The relative importance of various uncertainties involved in the computational process on the resulting bounds of P sub f, sensitivity is analyzed. Response sensitivities for both mode and system reliability of an ideal plastic portal frame are shown.

  11. Finite element historical deformation analysis in piecewise linear plasticity by mathematical programming

    International Nuclear Information System (INIS)

    De Donato, O.; Parisi, M.A.

    1977-01-01

    When loads increase proportionally beyond the elastic limit in the presence of elastic-plastic piecewise-linear constitutive laws, the problem of finding the whole evolution of the plastic strain and displacements of structures was recently shown to be amenable to a parametric linear complementary problem (PLCP) in which the parameter is represented by the load factor, the matrix is symmetric positive definite or at least semi-definite (for perfect plasticity) and the variables with a direct mechanical meaning are the plastic multipliers. With reference to plane trusses and frames with elastic-plastic linear work-hardening material behaviour numerical solutions were also fairly efficiently obtained using a recent mathematical programming algorithm (due to R.W. Cottle) which is able to provide the whole deformation history of the structure and, at the same time to rule out local unloadings along the given proportional loading process by means of 'a priori' checks carried out before each pivotal step of the procedure. Hence it becomes possible to use the holonomic (reversible, path-independent) constitutive laws in finite terms and to benefit by all the relevant numerical and computational advantages despite the non-holonomic nature of plastic behaviour. In the present paper the method of solution is re-examined in view to overcome an important drawback of the algorithm deriving from the size of PLCP fully populated matrix when structural problems with large number of variables are considered and, consequently, the updating, the storing or, generally, the handling of the current tableau may become prohibitive. (Auth.)

  12. Plastic Limit Loads for Slanted Circumferential Through-Wall Cracked Pipes Using 3D Finite-Element Limit Analyses

    International Nuclear Information System (INIS)

    Jang, Hyun Min; Cho, Doo Ho; Kim, Young Jin; Huh, Nam Su; Shim, Do Jun; Choi, Young Hwan; Park, Jung Soon

    2011-01-01

    On the basis of detailed 3D finite-element (FE) limit analyses, the plastic limit load solutions for pipes with slanted circumferential through-wall cracks (TWCs) subjected to axial tension, global bending, and internal pressure are reported. The FE model and analysis procedure employed in the present numerical study were validated by comparing the present FE results with existing solutions for plastic limit loads of pipes with idealized TWCs. For the quantification of the effect of slanted crack on plastic limit load, slant correction factors for calculating the plastic limit loads of pipes with slanted TWCs from pipes with idealized TWCs are newly proposed from extensive 3D FE calculations. These slant-correction factors are presented in tabulated form for practical ranges of geometry and for each set of loading conditions

  13. A 3D elasto-plastic soil model for lateral buckling analysis

    DEFF Research Database (Denmark)

    Hededal, Ole; Strandgaard, Torsten

    2008-01-01

    Modeling the lay-down of pipelines and subsequently the in- service conditions for a pipeline involves definition of a pipe-soil interaction model. A generalized true 3D elasto-plastic spring element based on an anisotropic hardening/degradation model for sliding is presented. The basis...... for the model is the elasto-plastic framework. A generic format is selected, allowing different yield criteria and flow rules to be implemented in a simple way. The model complies to a finite element format allowing it to be directly implemented into a standard finite element code. Examples demonstrating...

  14. MIT miniaturized disk bend test

    International Nuclear Information System (INIS)

    Harling, O.K.; Lee, M.; Sohn, D.S.; Kohse, G.; Lau, C.W.

    1983-01-01

    A miniaturized disk bend test (MDBT) using transmission electron microscopy specimens for the determination of various mechanical properties is being developed at MIT. Recent progress in obtaining strengths and ductilities of highly irradiated metal alloys is reviewed. Other mechanical properties can also be obtained using the MDBT approach. Progress in fatigue testing and in determination of the ductile-to-brittle transition temperature is reviewed briefly. 11 figures

  15. Effect of tensile properties on time-dependent C(t) and J(t) integrals in elastic-plastic-creep FE analysis

    International Nuclear Information System (INIS)

    Lee, So-Dam; Lee, Han-Sang; Kim, Yun-Jae; Ainsworth, Robert A.; Dean, David W.

    2016-01-01

    This technical note presents the effect of elastic-plastic properties on calculated time-dependent C(t) and J(t) values. This is investigated via systematic elastic-plastic-creep finite element (FE) analysis. Three different stress-strain curves are used, having essentially the same plastic properties at large strains but different tensile data near the 0.2% proof (yield) strength. It is found that the plastic property in stress-strain curve affects the FE C(t) values only at short times (within approximately 20% of the redistribution time). The plastic property affects the initial J values at time t = 0 but not the rate of change of J(t) with time. - Highlights: • The effect of elastic-plastic properties on calculated time-dependent C(t) and J(t) values is presented via FE analysis. • The plastic property affects the FE C(t) values only at short times up to ∼20% of the redistribution time. • The plastic property affects the initial J values at time t = 0 but not the rate of change of J(t) with time.

  16. In-situ nanomechanical study on bending characteristics of individual multi-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Ping-Chi, E-mail: pctjbenchen@yahoo.com.tw [Department of Mechanical Engineering, National Chung Cheng University, Chia-Yi 621, Taiwan (China); Advanced Institute of Manufacturing with High-Tech Innovations, National Chung Cheng University, Chia-Yi 621, Taiwan (China); Jeng, Yeau-Ren, E-mail: imeyrj@ccu.edu.tw [Department of Mechanical Engineering, National Chung Cheng University, Chia-Yi 621, Taiwan (China); Advanced Institute of Manufacturing with High-Tech Innovations, National Chung Cheng University, Chia-Yi 621, Taiwan (China)

    2016-03-21

    Bending characteristics of individual thin-walled carbon nanotubes (CNTs) are investigated through a novel in-situ nanoindentation in transmission electron microscopy. Unlike thick-walled CNTs, the graphitic layers of thin ones buckle into V-shaped kinks rather than Yoshimura ripples. These kinks are found to be entirely reversible without residual plastic deformation following unloading.

  17. Prevalence of Body Dysmorphic Disorder in Plastic Surgery and Dermatology Patients: A Systematic Review with Meta-Analysis.

    Science.gov (United States)

    Ribeiro, Rafael Vilela Eiras

    2017-08-01

    The aim of the present study was to evaluate the prevalence of body dysmorphic disorder in plastic surgery and dermatology patients, by performing a systematic review of the literature and meta-analysis. The most relevant studies published originally in any language were analyzed. The literature search was performed using the PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Scielo databases. The final sample comprised 33 publications that were submitted to meta-analysis. The study verified that 15.04% of plastic surgery patients had body dysmorphic disorder (range 2.21-56.67%); patient mean age was 34.54 ± 12.41 years, and most were women (74.38%). Among dermatology patients, 12.65% (range 4.52-35.16%) had body dysmorphic disorder; patient mean age was 27.79 ± 9.03 years, and most were women (76.09%). Both plastic surgeons and dermatologists must adequately assess their patients to identify those with a higher likelihood of body dysmorphic disorder and should arrange multidisciplinary care for such individuals. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  18. Cold bending of 34'' OD API 5L X80 pipes; Curvamento a frio de tubos API 5L X80 de 34'' de diametro

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ronaldo; Moreira, Fabio A.; Chad, Luis; Fritz, Marcelo C. [TenarisConfab, Pindamonhangaba, SP (Brazil); Batista, Gilmar Z.; Hippert, Eduardo [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    A key factor that demands special attention in the pipeline construction is the cold bending process, since 30 to 40% of the pipes use this process in the field. This study aimed to evaluate the X80 cold bending operational parameters, in order make viable the use of this process in the installation of future onshore pipelines. Three 34''OD x 0,750'' pipes were bended. The bending was conducted using a hydraulic equipment with application of equally spaced punches, recording the correspondent angles related to the elastic and plastic deformations in order to assess the spring-back effect and performing dimensional inspection. Samples from pipe and the weld were subjected to mechanical and metallographic tests. It was possible to obtain a 19 deg curve and 27D radius without presenting any evidence of wrinkles, out of roundness or any type of mechanical damage. After analysis, all criteria established from project specifications were complied, the mechanical tests performed allowed comparing pipe mechanical properties of straight and bended regions. The results of this study provide technical know how for future X80 onshore pipelines applications. (author)

  19. Effect of Bend Radius on Magnitude and Location of Erosion in S-Bend

    Directory of Open Access Journals (Sweden)

    Quamrul H. Mazumder

    2015-01-01

    Full Text Available Solid particle erosion is a mechanical process that removes material by the impact of solid particles entrained in the flow. Erosion is a leading cause of failure of oil and gas pipelines and fittings in fluid handling industries. Different approaches have been used to control or minimize damage caused by erosion in particulated gas-solid or liquid-solid flows. S-bend geometry is widely used in different fluid handling equipment that may be susceptible to erosion damage. The results of a computational fluid dynamic (CFD simulation of diluted gas-solid and liquid-solid flows in an S-bend are presented in this paper. In addition to particle impact velocity, the bend radius may have significant influence on the magnitude and the location of erosion. CFD analysis was performed at three different air velocities (15.24 m/s–45.72 m/s and three different water velocities (0.1 m/s–10 m/s with entrained solid particles. The particle sizes used in the analysis range between 50 and 300 microns. Maximum erosion was observed in water with 10 m/s, 250-micron particle size, and a ratio of 3.5. The location of maximum erosion was observed in water with 10 m/s, 300-micron particle size, and a ratio of 3.5. Comparison of CFD results with available literature data showed reasonable and good agreement.

  20. Predicting Residential Exposure to Phthalate Plasticizer Emitted from Vinyl Flooring - A Mechanistic Analysis

    Science.gov (United States)

    A two-room model is developed to estimate the emission rate of di-2-ethylhexyl phthalate (DEHP) from vinyl flooring and the evolving gas-phase and adsorbed surface concentrations in a realistic indoor environment. Adsorption isotherms for phthalates and plasticizers on interior ...

  1. Discrete dislocation plasticity analysis of loading rate-dependent static friction

    NARCIS (Netherlands)

    Song, H.; Deshpande, V. S.; van der Giessen, E.

    2016-01-01

    From a microscopic point of view, the frictional force associated with the relative sliding of rough surfaces originates from deformation of the material in contact, by adhesion in the contact interface or both. We know that plastic deformation at the size scale of micrometres is not only dependent

  2. Stochastic Finite Element Analysis of Non-Linear Structures Modelled by Plasticity Theory

    DEFF Research Database (Denmark)

    Frier, Christian; Sørensen, John Dalsgaard

    2003-01-01

    A Finite Element Reliability Method (FERM) is introduced to perform reliability analyses on two-dimensional structures in plane stress, modeled by non-linear plasticity theory. FERM is a coupling between the First Order Reliability Method (FORM) and the Finite Element Method (FEM). FERM can be us...

  3. A cohesive plastic/damage-zone model for ductile crack analysis

    International Nuclear Information System (INIS)

    Zhang, C.; Gross, D.

    1995-01-01

    A cohesive plastic/damage-zone model of the Dugdale-Barenblatt type (G.I. Barenblatt, Adv. Appl. Mech. 7 (1962) 55-129; D.S. Dugdale, J. Mech. Phys. Solids 8 (1960) 100-104) is presented for analyzing crack growth in ductile materials with damage evolution. A semi-infinite Mode I crack in plane stress or plane stress is considered. The damage is assumed to be present in form of dispersed microvoids which are localized into a narrow strip ahead of the crack-tip. A simple damage model of the Gurson model type (A.L. Gurson, J. Eng. Mater. Technol. 99 (1977) 2-15; V. Tvergaard, Advances in Applied Mechanics, Vol. 27, Academic Press, 1990, pp. 83-151) is developed for uniaxial tension to describe the macroscopic properties of the cohesive plastic/damage-zone. Under small-scale yielding and small-scale damage conditions, a system of nonlinear integral equations for the plastic strain and the length of the cohesive plastic/damage-zone is derived. Numerical results are presented and discussed to reveal the effect of damage evolution on the ductile crack growth. (orig.)

  4. Stability studies and degradation analysis of plastic solar cell materials by FTIR spectroscopy

    NARCIS (Netherlands)

    Neugebauer, H.; Brabec, C.J.; Hummelen, J.C.; Janssen, R.A.J.; Sariciftci, N.S.

    1999-01-01

    Results of controlled degradation experiments performed with the individual components and with the actual mixture used in plastic solar cells are shown. A testing procedure for the stability and for degradation effects under illumination in controlled atmosphere using FTIR-ATR spectroscopy is

  5. Analysis of non-phthalates plasticizers on porous graphitic carbon by supercritical fluid chromatography using evaporative light scattering detection.

    Science.gov (United States)

    Vaccher, Claude; Decaudin, Bertrand; Sautou, Valérie; Lecoeur, Marie

    2014-09-12

    The analysis of several plasticizers, widely used in the production of medical devices, was investigated on porous graphitic carbon (PGC) stationary phase in supercritical fluid chromatography (SFC) with an evaporative light scattering detector (ELSD). Due to strong interaction of compounds with the PGC support, solvents of strong eluotropic strength were added to the CO2 supercritical fluid. The effect of alkyl chain (pentane, hexane, heptane) and chlorinated (CH2Cl2, CHCl3, CCl4) solvents was studied on the retention and on the ELSD detection of plasticizers. A co-solvent mixture composed of CHCl3/heptane, eluted under gradient mode, allowed a significant improvement of the ELSD response compared to the use of each solvent individually. Then, a central composite design (CCD) was implemented to optimize both the separation and the detection of plasticizers. The parameters involved were the outlet pressure, the gradient slope, the co-solvent composition and the drift tube temperature of the ELSD. After optimization, baseline separation of plasticizers was achieved in 7min and best signal-to-noise ratios were obtained with outlet pressure and drift tube temperature of ELSD set at 200bar and 31°C, respectively. The co-solvent mixture was also composed of CHCl3/heptane (35/65 v/v) and a gradient from 15 to 60% of co-solvent in 2.2min was employed. The results demonstrated that CCD is a powerful tool for the optimization of SFC/ELSD method and the response surface model analysis can provide statistical understandings of the significant factors required to achieve optimal separation and ELSD sensitivity. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Moisture Absorption/Desorption Effects on Flexural Property of Glass-Fiber-Reinforced Polyester Laminates: Three-Point Bending Test and Coupled Hygro-Mechanical Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Xu Jiang

    2016-08-01

    Full Text Available Influence of moisture absorption/desorption on the flexural properties of Glass-fibre-reinforced polymer (GFRP laminates was experimentally investigated under hot/wet aging environments. To characterize mechanical degradation, three-point bending tests were performed following the ASTM test standard (ASTM D790-10A. The flexural properties of dry (0% Mt/M∞, moisture unsaturated (30% Mt/M∞ and 50% Mt/M∞ and moisture saturated (100% Mt/M∞ specimens at both 20 and 40 °C test temperatures were compared. One cycle of moisture absorption-desorption process was considered in this study to investigate the mechanical degradation scale and the permanent damage of GFRP laminates induced by moisture diffusion. Experimental results confirm that the combination of moisture and temperature effects sincerely deteriorates the flexural properties of GFRP laminates, on both strength and stiffness. Furthermore, the reducing percentage of flexural strength is found much larger than that of E-modulus. Unrecoverable losses of E-modulus (15.0% and flexural strength (16.4% for the GFRP laminates experiencing one cycle of moisture absorption/desorption process are evident at the test temperature of 40 °C, but not for the case of 20 °C test temperature. Moreover, a coupled hygro-mechanical Finite Element (FE model was developed to characterize the mechanical behaviors of GFRP laminates at different moisture absorption/desorption stages, and the modeling method was subsequently validated with flexural test results.

  7. Effect of local wall thinning on the collapse behavior of pipe elbows subjected to a combined internal pressure and in-plane bending load

    International Nuclear Information System (INIS)

    Kim, Jin-Weon; Na, Man-Gyun; Park, Chi-Yong

    2008-01-01

    The objective of this study was to investigate the effect of local wall thinning on the collapse behavior of pipe elbows subjected to a combined internal pressure and in-plane bending load. This study evaluated the global deformation behavior and collapse moment of the elbows, which contained various types of local wall-thinning defects at their intrados or extrados, using three-dimensional elastic-plastic finite element analysis. The analysis results showed that the global deformation behavior of locally wall-thinned elbows was largely governed by the mode of the bending and the elbow geometry rather than the wall-thinning parameters, except for elbows with considerably large and deep wall thinning that showed plastic instabilities induced by local buckling and plastic collapsing in the thinned area. The reduction in the collapse moment with wall-thinning depth was considerable when local buckling occurred in the thinned areas, whereas the effect of the thinning depth was small when ovalization occurred. The effects of the circumferential thinning angle and thinning length on the collapse moment of elbows were not major for shallow wall-thinning cases. For deeper wall-thinning cases, however, their effects were significant and the dependence of collapse moment on the axial thinning length was governed by the stress type applied to the wall-thinned area. Typically, the reduction in the collapse moment due to local wall thinning was clearer when the thinning defect was located at the intrados rather than the extrados, and it was apparent for elbows with larger bend radius

  8. Limit moments for non circular cross-section (elliptical) pipe bends

    International Nuclear Information System (INIS)

    Spence, J.

    1977-01-01

    A number of experiment studies have been reported or are underway which investigate limit moments applied to pipe bends. Some theoretical work is also available. However, most of the work has been confined to nominally circular cross-section bends and little account has been taken of the practical problem of manufacturing tolerances. Many methods of manufacture result in bends which are not circular in cross-section but have an oval or elliptical shape. The present paper extends previous analyses on circular bends to cater for initially elliptical cross-sections. The loading is primarily in plane bending but out of plane is also considered and several independent methods are presented. No previous information is known to the authors. Upper and lower bound limit moments are derived first of all from existing linear elastic analyses and secondly upper bound moments are derived via a plastic analogy from existing stationary creep results. It is also shown that the creep information on design factors for bends can be used to obtain a reasonable estimate of the complete moment/strain behaviour of a bend or indeed a system. (Auth.)

  9. 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.

  10. ARE PLASTIC GROCERY BAGS SACKING THE ENVIRONMENT?

    OpenAIRE

    Mangal Gogte

    2009-01-01

    This paper is oriented on analysis impacts of plastic bags on environment. In this paper is analyzed did plastic bags are so harmful, and what are the main ingredients of it. One part of this paper is oriented on effects of plastic bags and management of their usage. There is also made comparative analysis between impacts of plastic and paper bags on environment.

  11. Spatially resolved analysis of short-range structure perturbations in a plastically bent molecular crystal

    Science.gov (United States)

    Panda, Manas K.; Ghosh, Soumyajit; Yasuda, Nobuhiro; Moriwaki, Taro; Mukherjee, Goutam Dev; Reddy, C. Malla; Naumov, Panče

    2015-01-01

    The exceptional mechanical flexibility observed with certain organic crystals defies the common perception of single crystals as brittle objects. Here, we describe the morphostructural consequences of plastic deformation in crystals of hexachlorobenzene that can be bent mechanically at multiple locations to 360° with retention of macroscopic integrity. This extraordinary plasticity proceeds by segregation of the bent section into flexible layers that slide on top of each other, thereby generating domains with slightly different lattice orientations. Microscopic, spectroscopic and diffraction analyses of the bent crystal showed that the preservation of crystal integrity when stress is applied on the (001) face requires sliding of layers by breaking and re-formation of halogen-halogen interactions. Application of stress on the (100) face, in the direction where π···π interactions dominate the packing, leads to immediate crystal disintegration. Within a broader perspective, this study highlights the yet unrecognized extraordinary malleability of molecular crystals with strongly anisotropic supramolecular interactions.

  12. Analysis of plasticiser migration to meat roasted in plastic bags by SPME-GC/MS.

    Science.gov (United States)

    Moreira, Miriany Avelino; André, Leiliane Coelho; Cardeal, Zenilda de Lourdes

    2015-07-01

    Plasticisers are compounds used in the polymer industry to increase the flexibility of plastics. Some of these compounds cause endocrine dysfunction in humans and animals by interfering with the production, release, transport, metabolism, binding or elimination of natural hormones in the body and are therefore recognised as endocrine disruptors. This paper describes cold-fibre solid-phase microextraction as a sampling technique to analyse eight plasticisers in spices and roasted chicken meat stored in plastic bags by gas chromatography-mass spectrometry. Limits of detection for this method ranged from 0.01 to 0.18 μg kg(-)(1). Diisobutyl phthalate and dibutyl phthalate were found in the samples of spices and roasted chicken meat. The highest concentrations of plasticisers were found in the spices used to cook the chicken meat. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Analysis of Phthalate Ester Content in PVC Plastics by means of FT-Raman Spectroscopy

    DEFF Research Database (Denmark)

    Nørbygaard, Thomas; Berg, Rolf W.

    2004-01-01

    Polyvinyl chloride, PVC or [CH2-CHCl]n , is a common polymer used extensively for a wide range of industrial and household products. To achieve the proper material characteristics (e.g. softness, ductility), plasticizers such as phthalates are usually added to the otherwise hard and brittle PVC......, medical devices and toys may harm the e.g. reproductive organs of exposed infants. PVC is readily distinguished from other common polymers (e.g. polyethylene, polypropylene, polystyrene) by the use of Raman spectroscopy. By far the most commonly used phthalate plasticizer in PVC is di(2-ethylhexyl......-phenyl group, and as the relative intensities of the six bands vary only slightly from one phthalate ester to the next one we have obtained an identifiable, characteristic fingerprint of the phthalate ester group as a whole. By use of the set of six bands, which are common to all the measured Raman spectra, we...

  14. Bending and stretching of plates

    CERN Document Server

    Mansfield, E H; Hemp, W S

    1964-01-01

    The Bending and Stretching of Plates deals with elastic plate theory, particularly on small- and large-deflexion theory. Small-deflexion theory concerns derivation of basic equations, rectangular plates, plates of various shapes, plates whose boundaries are amenable to conformal transformation, plates with variable rigidity, and approximate methods. Large-deflexion theory includes general equations and some exact solutions, approximate methods in large-deflexion theory, asymptotic large-deflexion theories for very thin plates. Asymptotic theories covers membrane theory, tension field theory, a

  15. The travail of River Bend

    International Nuclear Information System (INIS)

    Studness, C.M.

    1990-01-01

    This article looks at the attempts by Gulf States Utilities to get the River Bend Nuclear Plant into its rate base. The review begins with the initial filing of rate cases in Texas and Louisiana in 1986 and continues through many court cases and appeals all the way to the Texas Supreme Court. The preferred and preference shareholders now nominally control the company through election of 10 of 15 members of the company's board of directors. This case is used as an argument for deregulation in favor of competition

  16. Perfect plasticity with damage and healing at small strains, its modeling, analysis, and computer implementation

    Czech Academy of Sciences Publication Activity Database

    Roubíček, Tomáš; Valdman, Jan

    2016-01-01

    Roč. 76, č. 1 (2016), s. 314-340 ISSN 0036-1399 R&D Projects: GA ČR GA13-18652S; GA ČR GA14-15264S Institutional support: RVO:67985556 ; RVO:61388998 Keywords : Prandtl-Reuss perfect plasticity * bounded-deformation space * incomplete damage Subject RIV: BA - General Mathematics Impact factor: 1.670, year: 2016 http://library.utia.cas.cz/separaty/2016/MTR/valdman-0458557.pdf

  17. Analysis of field usage failure rate data for plastic encapsulated solid state devices

    Science.gov (United States)

    1981-01-01

    Survey and questionnaire techniques were used to gather data from users and manufacturers on the failure rates in the field of plastic encapsulated semiconductors. It was found that such solid state devices are being successfully used by commercial companies which impose certain screening and qualification procedures. The reliability of these semiconductors is now adequate to support their consideration in NASA systems, particularly in low cost systems. The cost of performing necessary screening for NASA applications was assessed.

  18. Elastic-plastic analysis of local and integral straining behaviour in a cracked plate

    International Nuclear Information System (INIS)

    Grueter, L.; Ruettenauer, B.

    1982-01-01

    For components of the primary coolant system of the German LMFBR prototype reactor SNR-300, integrity against anticipated accidents (Bethe-Tait) has to be shown for a cracked structure. Within this programme a number of tests with cracked wide plate specimens yielding overall limit strains of approximately 15% have been run; finite element calculations have been infinated for the wide plate geometry. The paper discusses the straining behaviour of a cracked plate by considering the numerical simulation of structures strained up to such high levels. The stress-strain diagram of the weldment of the austenitic stainless steel X6 CrNi 18 at 450 0 C has been used. Plane strain and stress conditions have been prescribed. The original plate dimensions (t = thickness = 40 mm; h = height = 400 mm) have been used as well as a similar, but smaller plate of t = 8.8 mm width. The crack length is defined as 0.1 t. The results show that for a cracked plate under high plastic strain the near-crack-tip-field values still govern the structural mechanical behaviour. Concerning the absolute dimensions the effects known for elasticity retain their influence in the plastic regime; however, the crack location becomes more unimportant with increasing strain, i.e. the appropriate pure geometry factor tends to unity in the plastic regime. The center-crack, defined as 2a = 0.1 t, corresponds to an equivalent edge crack of depth a = 0.05 t in the elastic case. It can be shown that for high plastic strains this correspondence remains fully valid. (orig.)

  19. On unifying concepts in plasticity theory and related matters in numerical analysis

    International Nuclear Information System (INIS)

    Havner, K.S.

    1977-01-01

    This paper reviews a rate-independent theory (or class of theories) of multiple-mode plastic straining which unifies various constitutive equations of macroscopic solids and single crystals. Some consideration is given to the relationship between the multiple-mode theory and thermodynamic concepts; including physical aspects of finite distortion of metal crystals. Uniqueness criteria and related minimum principles in incremental (or 'rate-type') boundary value problems are presented for the general class at finite strain. Special circumstances (one being infinitesimal strain) are defined under which the uniqueness criteria assure convergence of a form of finite element approximation in the boundary value problem. Extensive reference is made to recently published work of Hill, Rice, Sewell and Havner. A symmetry postulate pertaining to the 'effective hardening moduli' plays a key role in the general theory. This postulate permits the adoption of Sewell's multiple-mode saddle function as a potential for stress and plastic mechanism rates and leads to the connection between uniqueness and (rate-type) minimum principles. The postulate has a remarkable consequence for application of a simple form of the theory to single crystals in the tensile test. At small strain this theory reduces to the classical Taylor hardening of crystals, which has had wide application in micromechanical calculations of crystalline aggregate models. At infinitesimal strain, and at finite strain when the two dominant principal stresses are everywhere tensile, additional minimum principles are given for the 'self-straining problem' which permit the independent variation of displacement and plastic mechanism rates

  20. Hydraulic pressure pulses with elastic and plastic structural flexibility: test and analysis (LWBR Development Program)

    International Nuclear Information System (INIS)

    Schwirian, R.E.

    1978-03-01

    Pressure pulse tests were conducted with a flexible test section in a test vessel filled with room temperature water. The pressure pulses were generated with a drop hammer and piston pulse generator and were of a sufficient magnitude to cause plastic deformation of the test section. Because of the strong pressure relief effect of the deforming test section, pressure pulse magnitudes were below 265 psig in magnitude and had durations of 50 to 55 msecs. Calculations performed with the FLASH-35 bi-linear hysteresis model of structural deformation show good agreement with experiment. In particular, FLASH 35 adequately predicts the decrease in peak pressure and the increase in pulse duration due to elastic and plastic deformation of the test section. Predictions of flexible member motion are good, but are less satisfactory than the pressure pulse results due to uncertainties in the values of yield point and beyond yield stiffness used to model the various flexible members. Coupled with this is a strong sensitivity of the FLASH 35 predictions to the values of yield point and beyond yield stiffness chosen for the various flexible members. The test data versus calculation comparisons presented here provide preliminary qualification for FLASH 35 calculations of transient hydraulic pressures and pressure differentials in the presence of flexible structural members which deform both elastically and plastically

  1. Shakedown Analysis of Composite Steel-Concrete Frame Systems with Plastic and Brittle Elements Under Seismic Action

    Directory of Open Access Journals (Sweden)

    Alawdin Piotr

    2017-06-01

    Full Text Available In this paper the earthquake analysis of composite steel-concrete frames is performed by finding solution of the optimization problem of shakedown analysis, which takes into account the nonlinear properties of materials. The constructions are equipped with systems bearing structures of various elastic-plastic and brittle elements absorbing energy of seismic actions. A mathematical model of this problem is presented on the base of limit analysis theory with partial redistribution of self-stressed internal forces. It is assumed that the load varies randomly within the specified limits. These limits are determined by the possible direction and magnitude of seismic loads. The illustrative example of such analysis of system is introduced. Some attention has been paid to the practical application of the proposed mathematical model.

  2. Shakedown Analysis of Composite Steel-Concrete Frame Systems with Plastic and Brittle Elements Under Seismic Action

    Science.gov (United States)

    Alawdin, Piotr; Bulanov, George

    2017-06-01

    In this paper the earthquake analysis of composite steel-concrete frames is performed by finding solution of the optimization problem of shakedown analysis, which takes into account the nonlinear properties of materials. The constructions are equipped with systems bearing structures of various elastic-plastic and brittle elements absorbing energy of seismic actions. A mathematical model of this problem is presented on the base of limit analysis theory with partial redistribution of self-stressed internal forces. It is assumed that the load varies randomly within the specified limits. These limits are determined by the possible direction and magnitude of seismic loads. The illustrative example of such analysis of system is introduced. Some attention has been paid to the practical application of the proposed mathematical model.

  3. Cholesterol biosensor based on a plastic optical fibre with sol-gel: structural analysis and sensing properties

    Science.gov (United States)

    Razo-Medina, D. A.; Trejo-Durán, M.; Alvarado-Méndez, E.

    2018-02-01

    In this paper, we report the design and characterization of an optical fibre cholesterol biosensor by using sol-gel immobilization technique. The cholesterol enzyme is encapsulated inside of the sol-gel film onto an end of a plastic optical fibre. Two film deposition methods (Dip-Coating and Immersion) were studied. The morphology analysis and sensing properties permit us to determine the best film deposition to sense cholesterol concentration. The range of measured is 4.4-5.2 mM in real time and our results were validated by comparing them with other previously published results. The biosensor is portable, simple cheap, and easy to use.

  4. Assessment of stress-strain data suitable for finite-element elastic--plastic analysis of shipping containers

    International Nuclear Information System (INIS)

    Rack, H.J.; Knorovsky, G.A.

    1978-09-01

    Stress-strain data which describes the influence of strain rate and temperature on the mechanical response of materials presently being used for light water reactor fuel shipping containers have been assembled. Selection of data has been limited to that which is suitable for use in finite-element elastic--plastic analysis of shipping containers (e.g., they must include complete material history profiles). Based on this information, recommendations have been made for further work which is required to complete the necessary data base

  5. Dendrogeochronologic and Anatomic Analysis of Excavated Plains Cottonwoods Determine Overbank Sedimentation Rates and Historical Channel Positions Along the Interior of a Migrating Meander Bend, Powder River, Montana

    Science.gov (United States)

    Metzger, T. L.; Pizzuto, J. E.; Schook, D. M.; Hasse, T. R.; Affinito, R. A.

    2017-12-01

    Dendrochronological dating of buried trees precisely determines the germination year and identifies the stratigraphic context of germination for the trees. This recently developed application of dendrochronology provides accurate time-averaged sedimentation rates of overbank deposition along floodplains and can be used to identify burial events. Previous studies have demonstrated that tamarisk (Tamarix ramosissima) and sandbar willow (Salix exigua) develop anatomical changes within the tree rings (increased vessel size and decreased ring widths) on burial, but observations of plains cottonwood (Populus deltoides ssp. monilifera) are lacking. In September 2016 and June 2017, five buried plains cottonwoods were excavated along a single transect of the interior of a meander bend of the Powder River, Montana. Sediment samples were obtained near each tree for 210Pb and 137Cs dating, which will allow for comparison between dendrochronological and isotopic dating methods. The plains cottonwood samples collected exhibit anatomical changes associated with burial events that are observed in other species. All trees germinated at the boundary between thinly bedded fine sand and mud and coarse sand underlain by sand and gravel, indicating plains cottonwoods germinate on top of point bars prior to overbank deposition. The precise germination age and depth provide elevations and minimum age constraints for the point bar deposits and maximum ages for the overlying sediment, helping constrain past channel positions and overbank deposition rates. Germination years of the excavated trees, estimated from cores taken 1.5 m above ground level, range from 2014 to 1862. Accurate establishment years determined by cross-dating the buried section of the tree can add an additional 10 years to the cored age. The sedimentation rate and accumulation thickness varied with tree age. The germination year, total sediment accumulation, and average sedimentation rate at the five sampled trees is

  6. Involvement of Sodium Nitroprusside (SNP in the Mechanism That Delays Stem Bending of Different Gerbera Cultivars

    Directory of Open Access Journals (Sweden)

    Aung H. Naing

    2017-11-01

    Full Text Available Longevity of cut flowers of many gerbera cultivars (Gerbera jamesonii is typically short because of stem bending; hence, stem bending that occurs during the early vase life period is a major problem in gerbera. Here, we investigated the effects of sodium nitroprusside (SNP on the delay of stem bending in the gerbera cultivars, Alliance, Rosalin, and Bintang, by examining relative fresh weight, bacterial density in the vase solution, transcriptional analysis of a lignin biosynthesis gene, antioxidant activity, and xylem blockage. All three gerbera cultivars responded to SNP by delaying stem bending, compared to the controls; however, the responses were dose- and cultivar-dependent. Among the treatments, SNP at 20 mg L-1 was the best to delay stem bending in Alliance, while dosages of 10 and 5 mg L-1 were the best for Rosalin and Bintang, respectively. However, stem bending in Alliance and Rosalin was faster than in Bintang, indicating a discrepancy influenced by genotype. According to our analysis of the role of SNP in the delay of stem bending, the results revealed that SNP treatment inhibited bacterial growth and xylem blockage, enhanced expression levels of a lignin biosynthesis gene, and maintained antioxidant activities. Therefore, it is suggested that the cause of stem bending is associated with the above-mentioned parameters and SNP is involved in the mechanism that delays stem bending in the different gerbera cultivars.

  7. Validity of fracture toughness determined with small bend specimens

    International Nuclear Information System (INIS)

    Wallin, K.; Rintamaa, R.; Valo, M.

    1994-02-01

    This report considers the validity of fracture toughness estimates obtained with small bend specimens in relation to fracture toughness estimates obtained with large specimens. The study is based upon the analysis and comparison of actual test results. The results prove the validity of the fracture toughness determined based upon small bend specimens, especially when the results are only used to determine the fracture toughness transition temperature T o . In this case the possible error is typically less than 5 deg C and at most 10 deg C. It can be concluded that small bend specimens are very suitable for the estimation of fracture toughness in the case of brittle fracture, provided the results are corrected for statistical size effects. (orig.). (20 refs., 17 figs.)

  8. Evaluation of River Bend Station Unit 1 Technical Specifications

    International Nuclear Information System (INIS)

    Baxter, D.E.; Bruske, S.J.

    1985-08-01

    This document was prepared for the Nuclear Regulatory Commission (NRC) to assist them in determining whether the River Bend Station Unit 1 Technical Specifications (T/S), which govern plant systems configurations and operations, are in conformance with the requirements of the Final Safety Analysis Report (FSAR) as amended, and the requirements of the Safety Evaluation Report (SER) as supplemented. A comparative audit of the FSAR as amended, and the SER as supplemented was performed with the River Bend T/S. Several discrepancies were identified and subsequently resolved through discussions with the cognizant NRC reviewer, NRC staff reviewers and/or utility representatives. The River Bend Station Unit 1 T/S, to the extent reviewed, are in conformance with the FSAR and SER

  9. Yield stress determination from miniaturized disk bend test data

    International Nuclear Information System (INIS)

    Sohn, D.S.; Kohse, G.; Harling, O.K.

    1985-04-01

    Methodology for testing 3.0 mm diameter by 0.25 mm thick disks by bending in a punch and die has been described previously. This paper describes the analysis of load/deflection data from such miniaturized disk bend tests (MDBT) using a finite element simulation. Good simulation has been achieved up to a point just beyond the predominantly elastic response, linear initial region. The load at which deviation from linearity begins has been found to correlate with yield stress, and yield stress has been successfully extracted from disk bend tests of a number of known materials. Although finite element codes capable of dealing with large strains and large rotations have been used, simulation of the entire load/deflection curve up to fracture of the specimen has not yet been achieved

  10. An Analysis of the Advantages of Reusable Plastic Containers in Strawberry Logistics : A Case Study of the Japan Agricultural Cooperative YOICHI

    OpenAIRE

    尾碕, 亨; 樋元, 淳一

    2014-01-01

    This article undertook a comparative analysis of cardboard boxes and reusable plastic containers and their impact on production logistics costs and the receipt prices of producers. The results showed that reusable plastic containers shortened logistical working hours, reduced production logistics costs and increased the receipt prices of the producer. However, exchange-value cannot realized if the quality of the farm product is not maintained, even if it is transported in superior packing con...

  11. Static analysis of a piping system with elbows

    International Nuclear Information System (INIS)

    Bryan, B.J.

    1994-01-01

    Vibration tests of elbows to failure were performed in Japan in the early 1970s. The piping system included two elbows and an eccentric mass. Tests were run both pressurized and unpressurized. This report documents a static analysis of the piping system in which the elbows are subjected to out of plane bending. The effects of internal pressure and material plasticity are investigated

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  13. What Do Our Patients Truly Want? Conjoint Analysis of an Aesthetic Plastic Surgery Practice Using Internet Crowdsourcing.

    Science.gov (United States)

    Wu, Cindy; Scott Hultman, C; Diegidio, Paul; Hermiz, Steven; Garimella, Roja; Crutchfield, Trisha M; Lee, Clara N

    2017-01-01

    What do patients want when looking for an aesthetic surgeon? When faced with attributes like reputation, years in practice, testimonials, photos, and pricing, which is more valuable? Moreover, are attributes procedure-specific? Currently, inadequate evidence exists on which attributes are most important to patients, and to our knowledge, none on procedure-specific preferences. First, to determine the most important attributes to breast augmentation, combined breast/abdominal surgery, and facelift patients using conjoint analysis. Second, to test the conjoint using an internet crowdsourcing service (Amazon Mechanical Turk [MTurk]). Anonymous university members were asked, via mass electronic survey, to pick a surgeon for facelift surgery based on five attributes. Attribute importance and preference was calculated. Once pre-tested, the facelift, breast augmentation and combined breast/abdominal surgery surveys were administered worldwide to MTurk. The university facelift cohort valued testimonials (33.9%) as the most important, followed by photos (31.6%), reputation (18.2%), pricing (14.4%), and practice years (1.9%). MTurk breast augmentation participants valued photos (35.3%), then testimonials (33.9%), reputation (15.7%), pricing (12.2%), and practice years (3%). MTurk combined breast/abdominal surgery and facelift participants valued testimonials (38.3% and 38.1%, respectively), then photos (27.9%, 29.4%), reputation (17.5%, 15.8%), pricing (13.9%, 13.9%), practice years (2.4%, 2.8%). Breast augmentation patients placed higher importance on photos; combined breast/abdominal surgery and facelift patients valued testimonials. Conjoint analysis has had limited application in plastic surgery. To our knowledge, internet crowdsourcing is a novel participant recruitment method in plastic surgery. Its unique benefits include broad, diverse and anonymous participant pools, low-cost, rapid data collection, and high completion rate. © 2016 The American Society for

  14. Catalytic co-pyrolysis of paper biomass and plastic mixtures (HDPE (high density polyethylene), PP (polypropylene) and PET (polyethylene terephthalate)) and product analysis

    International Nuclear Information System (INIS)

    Chattopadhyay, Jayeeta; Pathak, T.S.; Srivastava, R.; Singh, A.C.

    2016-01-01

    Catalytic co-pyrolysis of biomass and plastics (HDPE (high density polyethylene), PP (polypropylene) and PET (polyethylene terephthalate)) has been performed in a fixed-bed reactor in presence of cobalt based alumina, ceria and ceria-alumina catalysts to analyze the product distribution and selectivity. Catalysts are synthesized using co-precipitation method and characterized by BET (Brunauer–Emmett–Teller) surface area and XRD analysis. The effect of catalytic co-pyrolysis at different temperature with product distribution has been evaluated. The results have clearly shown the synergistic effect between biomass and plastics, the liquid products gradually increases forming with rise in the plastic content in the blend. Gaseous products have yielded most during pyrolysis of blend having biomass/plastics ratio of 5:1 with the presence of 40% Co/30% CeO_2/30% Al_2O_3 catalyst with hydrogen gas production touched its peak of 47 vol%. Catalytic performance enhanced with increase with the cobalt loading, with best performance attributing to 40% Co/30% CeO_2/30% Al_2O_3 catalyst. - Highlights: • Catalytic co-pyrolysis of biomass and plastics (HDPE, PP & PET) blends in fixed-bed reactor. • Strong synergistic effect evident between biomass and plastics. • Solid residue diminished with application of catalysts. • Aromatics and olefins production increases with higher plastic content. • More hydrogen production with application of catalysts with higher cobalt content.

  15. Analysis of polyethylene terephthalate PET plastic bottle jointing system using finite element method (FEM)

    Science.gov (United States)

    Zaidi, N. A.; Rosli, Muhamad Farizuan; Effendi, M. S. M.; Abdullah, Mohamad Hariri

    2017-09-01

    For almost all injection molding applications of Polyethylene Terephthalate (PET) plastic was analyzed the strength, durability and stiffness of properties by using Finite Element Method (FEM) for jointing system of wood furniture. The FEM was utilized for analyzing the PET jointing system for Oak and Pine as wood based material of furniture. The difference pattern design of PET as wood jointing furniture gives the difference value of strength furniture itself. The results show the wood specimen with grooves and eclipse pattern design PET jointing give lower global estimated error is 28.90%, compare to the rectangular and non-grooves wood specimen of global estimated error is 63.21%.

  16. Design and Checking Analysis of Injection Mold for a Plastic Cup

    Science.gov (United States)

    Li, Xuebing

    2018-03-01

    A special injection mold was designed for the structural characteristics of a plastic cup part. The mold was simulated by Moldflow software and verified by calculating the stripping force, the pulling force and the clamping force of the mold so that to determine the appropriate injection parameters. It has been proved that the injection mold is effective and practical in the actual producing and can meet the quality requirements during the course of using it, which solved some problems for injection molding of this kind of parts and can provide some reference for the production of other products in the same industry.

  17. Instability analysis of a fully plastic center-cracked strip of a power hardening material

    International Nuclear Information System (INIS)

    Zahoor, A.; Paris, P.C.

    1978-01-01

    An approach for predicting unstable crack growth in a power hardening material is discussed. A fully plastic center-cracked strip of finite width under plane strain conditions, which involves J-controlled crack growth, is analyzed. The conditions for unstable crack growth are identified in terms of a non-dimensional parameter, the Tearing Modulus, T, which incorporates the effect of elastic system compliance on the cracked structure as well as the influence of hardening. Numerical results also illustrate the strong influences on stability of both the strain hardening characteristics of the material and certain geometrical proportions which greatly influence the system compliance. (author)

  18. Microchromatography of hemoglobins. VIII. A general qualitative and quantitative method in plastic drinking straws and the quantitative analysis of Hb-F.

    Science.gov (United States)

    Schroeder, W A; Pace, L A

    1978-03-01

    The microchromatographic procedure for the quantitative analysis of the hemoglobin components in a hemolysate uses columns of DEAE-cellulose in a plastic drinking straw with a glycine-KCN-NaCl developer. Not only may the method be used for the quantitative analysis of Hb-F but also for the analysis of the varied components in mixtures of hemoglobins.

  19. Static Buckling Model Tests and Elasto-plastic Finite Element Analysis of a Pile in Layers with Various Thicknesses

    Science.gov (United States)

    Okajima, Kenji; Imai, Junichi; Tanaka, Tadatsugu; Iida, Toshiaki

    Damage to piles in the liquefied ground is frequently reported. Buckling by the excess vertical load could be one of the causes of the pile damage, as well as the lateral flow of the ground and the lateral load at the pile head. The buckling mechanism is described as a complicated interaction between the pile deformation by the vertical load and the earth pressure change cased by the pile deformation. In this study, series of static buckling model tests of a pile were carried out in dried sand ground with various thickness of the layer. Finite element analysis was applied to the test results to verify the effectiveness of the elasto-plastic finite element analysis combining the implicit-explicit mixed type dynamic relaxation method with the return mapping method to the pile buckling problems. The test results and the analysis indicated the possibility that the buckling load of a pile decreases greatly where the thickness of the layer increases.

  20. Plastic dosimeter

    International Nuclear Information System (INIS)

    Nagai, Shiro; Matsuda, Kohji.

    1988-01-01

    The report outlines major features and applications of plastic dosimeters. Some plastic dosimeters, including the CTA and PVC types, detect the response of the plastic material itself to radiations while others, such as pigment-added plastic dosimeters, contain additives as radiation detecting material. Most of these dosimeters make use of color centers produced in the dosimeter by radiations. The PMMA dosimeter is widely used in the field of radiation sterilization of food, feed and medical apparatus. The blue cellophane dosimeter is easy to handle if calibrated appropriately. The rad-color dosimeter serves to determine whether products have been irradiated appropriately. The CTA dosimeter has better damp proofing properties than the blue cellophane type. The pigment-added plastic dosimeter consists of a resin such as nylon, CTA or PVC that contains a dye. Some other plastic dosimeters are also described briefly. Though having many advantages, these plastic dosimeter have disadvantages as well. Some of their major disadvantages, including fading as well as large dependence on dose, temperature, humidity and anviroment, are discussed. (Nogami, K.)

  1. Analysis of the efficacy of marketing tools in facial plastic surgery.

    Science.gov (United States)

    Zavod, Matthew B; Adamson, Peter A

    2008-06-01

    To compare referral sources to a facial plastic surgery practice and to develop models correlating the referral source with the decision for surgery. Retrospective descriptive study. Well-established, metropolitan, private facial plastic surgery practice with training fellowship affiliated with an academic centre. One-thousand eighty-nine new consecutive patients presenting between January 2001 and December 2005 recorded intake data including age, gender, and chief complaint. Final data input was their decision for or against surgery. Main outcome measures included differences in referral sources based on data collected and how those sources related to decision for surgery. A 50% conversion rate was found. Women and older patients were more likely to be referred from magazines, television, and newspapers and for facial rejuvenation. Men and younger patients were more likely to be referred from the website and for rhinoplasty. For facial rejuvenation, both the number of patients interested in and the probability that they agreed to the procedure increased with age. For rhinoplasty, the converse was true. The most likely patients to schedule surgery were those who were referred from other patients, friends, or family members in our practice. The data confirm that word-of-mouth referrals are the most important source for predicting which patients will elect to proceed with surgery in this established facial cosmetic surgery practice.

  2. Wall Street's assessment of plastic surgery--related technology: a clinical and financial analysis.

    Science.gov (United States)

    Krieger, L M; Shaw, W W

    2000-02-01

    Many plastic surgeons develop technologies that are manufactured by Wall Street-financed companies. Others participate in the stock market as investors. This study examines the bioengineered skin industry to determine whether it integrates clinical and financial information as Wall Street tenets would predict, and to see whether the financial performance of these companies provides any lessons for practicing plastic surgeons. In efficient markets, the assumptions on which independent financial analysts base their company sales and earnings projections are clinically reasonable, the volatility of a company's stock price does not irrationally differ from that of its industry sector, and the buy/sell recommendations of analysts are roughly congruent. For the companies in this study, these key financial parameters were compared with a benchmark index of 69 biotech companies of similar age and annual revenues (Student's t test). Five bioengineered skin companies were included in the study. Analysts estimated that each company would sell its product to between 24 and 45 percent of its target clinical population. The average stock price volatility was significantly higher for study companies than for those in the benchmark index (p companies were significantly less congruent than those for the benchmark companies (p invest in the stock market, because of their unique clinical experience, may sometimes be in the position to evaluate new technologies and companies better than Wall Street experts. Well-timed trades that use this expertise can result in opportunities for profit.

  3. Analysis of metal forming processes by using physical modeling and new plastic similarity condition

    International Nuclear Information System (INIS)

    Gronostajski, Z.; Hawryluk, M.

    2007-01-01

    In recent years many advances have been made in numerical methods, for linear and non-linear problems. However the success of them depends very much on the correctness of the problem formulation and the availability of the input data. Validity of the theoretical results can be verified by an experiment using the real or soft materials. An essential reduction of time and costs of the experiment can be obtained by using soft materials, which behaves in a way analogous to that of real metal during deformation. The advantages of using of the soft materials are closely connected with flow stress 500 to 1000 times lower than real materials. The accuracy of physical modeling depend on the similarity conditions between physical model and real process. The most important similarity conditions are materials similarity in the range of plastic and elastic deformation, geometrical, frictional and thermal similarities. New original plastic similarity condition for physical modeling of metal forming processes is proposed in the paper. It bases on the mathematical description of similarity of the flow stress curves of soft materials and real ones

  4. The variability of the trunk forward bending in standing activities during work vs. leisure time

    DEFF Research Database (Denmark)

    Villumsen, Morten; Madeleine, Pascal; Jørgensen, Marie Birk

    2017-01-01

    . The study was conducted on 657 blue-collar workers. Two accelerometers were used to identify the body posture and forward bending of the trunk during work and leisure time. The pattern of forward bending was analyzed using exposure variation analysis (EVA). The recordings comprised of 2.6 ± 0.97 working...

  5. An econometric analysis of regional differences in household waste collection: the case of plastic packaging waste in Sweden.

    Science.gov (United States)

    Hage, Olle; Söderholm, Patrik

    2008-01-01

    The Swedish producer responsibility ordinance mandates producers to collect and recycle packaging materials. This paper investigates the main determinants of collection rates of household plastic packaging waste in Swedish municipalities. This is done by the use of a regression analysis based on cross-sectional data for 252 Swedish municipalities. The results suggest that local policies, geographic/demographic variables, socio-economic factors and environmental preferences all help explain inter-municipality collection rates. For instance, the collection rate appears to be positively affected by increases in the unemployment rate, the share of private houses, and the presence of immigrants (unless newly arrived) in the municipality. The impacts of distance to recycling industry, urbanization rate and population density on collection outcomes turn out, though, to be both statistically and economically insignificant. A reasonable explanation for this is that the monetary compensation from the material companies to the collection entrepreneurs vary depending on region and is typically higher in high-cost regions. This implies that the plastic packaging collection in Sweden may be cost ineffective. Finally, the analysis also shows that municipalities that employ weight-based waste management fees generally experience higher collection rates than those municipalities in which flat and/or volume-based fees are used.

  6. An econometric analysis of regional differences in household waste collection: The case of plastic packaging waste in Sweden

    International Nuclear Information System (INIS)

    Hage, Olle; Soederholm, Patrik

    2008-01-01

    The Swedish producer responsibility ordinance mandates producers to collect and recycle packaging materials. This paper investigates the main determinants of collection rates of household plastic packaging waste in Swedish municipalities. This is done by the use of a regression analysis based on cross-sectional data for 252 Swedish municipalities. The results suggest that local policies, geographic/demographic variables, socio-economic factors and environmental preferences all help explain inter-municipality collection rates. For instance, the collection rate appears to be positively affected by increases in the unemployment rate, the share of private houses, and the presence of immigrants (unless newly arrived) in the municipality. The impacts of distance to recycling industry, urbanization rate and population density on collection outcomes turn out, though, to be both statistically and economically insignificant. A reasonable explanation for this is that the monetary compensation from the material companies to the collection entrepreneurs vary depending on region and is typically higher in high-cost regions. This implies that the plastic packaging collection in Sweden may be cost ineffective. Finally, the analysis also shows that municipalities that employ weight-based waste management fees generally experience higher collection rates than those municipalities in which flat and/or volume-based fees are used

  7. Prediction of plastic deformation under contact condition by quasi-static and dynamic simulations using explicit finite element analysis

    International Nuclear Information System (INIS)

    Siswanto, W. A.; Nagentrau, M.; Tobi, A. L. Mohd; Tamin, M. N.

    2016-01-01

    We compared the quasi-static and dynamic simulation responses on elastic-plastic deformation of advanced alloys using Finite element (FE) method with an explicit numerical algorithm. A geometrical model consisting of a cylinder-on-flat surface contact under a normal load and sliding motion was examined. Two aeroengine materials, Ti-6Al-4V and Super CMV (Cr-Mo-V) alloy, were employed in the FE analysis. The FE model was validated by comparative magnitudes of the FE-predicted maximum contact pressure variation along the contact half-width length with the theoretical Hertzian contact solution. Results show that the (compressive) displacement of the initial contact surface steadily increases for the quasi-static load case, but accumulates at an increasing rate to the maximum level for the dynamic loading. However, the relatively higher stiffness and yield strength of the Super CMV alloy resulted in limited deformation and low plastic strain when compared to the Ti-6Al-4V alloy. The accumulated equivalent plastic strain of the material point at the initial contact position was nearly a thousand times higher for the dynamic load case (for example, 6.592 for Ti-6Al-4V, 1.0 kN) when compared to the quasi-static loading (only 0.0072). During the loading step, the von Mises stress increased with a decreasing and increasing rate for the quasi-static and dynamic load case, respectively. A sudden increase in the stress magnitude to the respective peak value was registered due to the additional constraint to overcome the static friction of the mating surfaces during the sliding step

  8. Prediction of plastic deformation under contact condition by quasi-static and dynamic simulations using explicit finite element analysis

    Energy Technology Data Exchange (ETDEWEB)

    Siswanto, W. A.; Nagentrau, M.; Tobi, A. L. Mohd [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, Batu Pahat (Malaysia); Tamin, M. N. [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Johor Bahru (Malaysia)

    2016-11-15

    We compared the quasi-static and dynamic simulation responses on elastic-plastic deformation of advanced alloys using Finite element (FE) method with an explicit numerical algorithm. A geometrical model consisting of a cylinder-on-flat surface contact under a normal load and sliding motion was examined. Two aeroengine materials, Ti-6Al-4V and Super CMV (Cr-Mo-V) alloy, were employed in the FE analysis. The FE model was validated by comparative magnitudes of the FE-predicted maximum contact pressure variation along the contact half-width length with the theoretical Hertzian contact solution. Results show that the (compressive) displacement of the initial contact surface steadily increases for the quasi-static load case, but accumulates at an increasing rate to the maximum level for the dynamic loading. However, the relatively higher stiffness and yield strength of the Super CMV alloy resulted in limited deformation and low plastic strain when compared to the Ti-6Al-4V alloy. The accumulated equivalent plastic strain of the material point at the initial contact position was nearly a thousand times higher for the dynamic load case (for example, 6.592 for Ti-6Al-4V, 1.0 kN) when compared to the quasi-static loading (only 0.0072). During the loading step, the von Mises stress increased with a decreasing and increasing rate for the quasi-static and dynamic load case, respectively. A sudden increase in the stress magnitude to the respective peak value was registered due to the additional constraint to overcome the static friction of the mating surfaces during the sliding step.

  9. Ductile failure of pipes with defects under combined pressure and bending

    International Nuclear Information System (INIS)

    Darlaston, B.J.L.; Harrison, R.P.

    1977-01-01

    The main part of the experimental programme was carried out on 3.5'' diam. pipes with a wall thickness of 0.064''. Various lengths of defect were assessed but only two depths, 0.044'' and 0.060''. Some full penetration defect tests were carried out under bending loading. The defects were 0.012'' wide and nominally flat bottomed. The tensile properties of the pipes were determined by taking specimens from each of the tubes. The pipes were exposed to pressure only test, bending only test and combined bending and pressure test. The results are given in tables. The observations led to the postulation of a design rule relating to the effect of defect in pipes under combined internal pressure and bending. It applies only to ductile situations in which the mode of failure is by a collapse mechanism: If the failure of a pipe containing an axial defect occurs by plastic collapse then provided the bending moment does not exceed half that for collapse due to bending alone, it will have a negligible effect on the failure pressure. (J.B.)

  10. Shakedown boundary determination of a 90° back-to-back pipe bend subjected to steady internal pressures and cyclic in-plane bending moments

    International Nuclear Information System (INIS)

    Abdalla, Hany F.

    2014-01-01

    No experimental data exist within open literature, to the best knowledge of the author, for determining shakedown boundaries of 90° back-to-back pipe bends. Ninety degree back-to-back pipe bends are extensively utilized within piping networks of nuclear submarines and modern turbofan aero-engines where space limitation is considered a paramount concern. In the current research, the 90° back-to-back pipe bend setup analyzed is subjected to a spectrum of steady internal pressures and cyclic in-plane bending moments. A previously developed direct non-cyclic simplified technique for determining elastic shakedown limit loads is utilized to generate the elastic shakedown boundary of the analyzed structure. The simplified technique outcomes showed excellent correlation with the results of full elastic–plastic cyclic loading finite element simulations. - Highlights: • No shakedown experimental data exist for 90° back-to-back pipe bends. • A non-cyclic technique is utilized to generate the elastic shakedown boundary. • The non-cyclic technique succeeded in generating the structure's Bree diagram. • The non-cyclic technique correlated well with full cyclic loading FE simulations

  11. PLASTIC SURGERY

    African Journals Online (AJOL)

    Department of Plastic and Reconstructive Surgery Sefako Makgatho Health Science University, ... We report on a pilot study on the use of a circumareolar excision and the use of .... and 1 gynecomastia patient) requested reduction in NAC size.

  12. Plastic Fishes

    CERN Multimedia

    Trettnak, Wolfgang

    2015-01-01

    In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness. The slideshow below gives you a taste of the artworks by Wolfgang Trettnak and Margarita Cimadevila.

  13. Determination of structural and mechanical properties, diffractometry, and thermal analysis of chitosan and hydroxypropylmethylcellulose (HPMC films plasticized with sorbitol

    Directory of Open Access Journals (Sweden)

    Jefferson Rotta

    2011-06-01

    Full Text Available In this work, the structural, mechanical, diffractometric, and thermal parameters of chitosan-hydroxypropylmethylcellulose (HPMC films plasticized with sorbitol were studied. Solutions of HPMC (2% w/v in water and chitosan (2% w/v in 2% acetic acid solution were prepared. The concentration of sorbitol used was 10% (w/w to both polymers. This solutions were mixed at different proportions (100/0; 70/30; 50/50; 30/70, and 0/100 of chitosan and HPMC, respectively, and 20 mL was cast in Petri dishes for further analysis of dried films. The miscibility of polymers was assessed by X-ray diffraction, scanning electronic microscopy (SEM, differential scanning calorimetry (DSC, and thermal gravimetric analysis (TGA. The results obtained indicate that the films are not fully miscible at a dry state despite the weak hydrogen bonding between the polymer functional groups.

  14. Co-pyrolysis characteristics and kinetic analysis of organic food waste and plastic.

    Science.gov (United States)

    Tang, Yijing; Huang, Qunxing; Sun, Kai; Chi, Yong; Yan, Jianhua

    2018-02-01

    In this work, typical organic food waste (soybean protein (SP)) and typical chlorine enriched plastic waste (polyvinyl chloride (PVC)) were chosen as principal MSW components and their interaction during co-pyrolysis was investigated. Results indicate that the interaction accelerated the reaction during co-pyrolysis. The activation energies needed were 2-13% lower for the decomposition of mixture compared with linear calculation while the maximum reaction rates were 12-16% higher than calculation. In the fixed-bed experiments, interaction was observed to reduce the yield of tar by 2-69% and promote the yield of char by 13-39% compared with linear calculation. In addition, 2-6 times more heavy components and 61-93% less nitrogen-containing components were formed for tar derived from mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Elastic-plastic fracture mechanics analysis of a pressure vessel with an axial outer surface flaw

    International Nuclear Information System (INIS)

    Aurich, D.

    1988-04-01

    Elastic-plastic finite element analyses of a test vessel (steel 1.6310=20 MnMoNi 55) with a semi-elliptical axial outer surface crack have been performed. The variations of J and CTOD along the crack front and the stresse state in the vicinity of the crack are presented. The applicability of approaches to determine J is examined. The FE results are compared with the experimental data. The results are analyzed with respect to the validity of J-controlled crack growth. It will be shown that the local ductile crack growth and, especially, the 'canoe effect' for a semi-elliptical crack can only be described correctly if local J R -curves are used which account for the varying triaxiality of the stress state along the crack front. (orig./HP) [de

  16. [Experimental study on carbon fiber reinforced plastic plate--analysis of stabilizing force required for plate].

    Science.gov (United States)

    Iizuka, H

    1990-11-01

    Plates currently in use for the management of bone fracture made of metal present with various problems. We manufactured carbon fiber reinforced plastic (CFRP) plates from Pyrofil T/530 puriplegs overlaid at cross angles of +/- 10 degrees, +/- 20 degrees, and +/- 30 degrees for trial and carried out an experimental study on rabbit tibiofibular bones using 316L stainless steel plates of comparable shape and size as controls. The results indicate the influence of CFRP plate upon cortical bone was milder than that of stainless steel plate, with an adequate stabilizing force for the repair of fractured rabbit tibiofibular bones. CFRP has the advantages over metals of being virtually free from corrosion and fatigue, reasonably radiolucent and able to meet a wide range of mechanical requirements. This would make CFRP plate quite promising as a new devices of treating fracture of bones.

  17. Predicting residential exposure to phthalate plasticizer emitted from vinyl flooring: a mechanistic analysis.

    Science.gov (United States)

    Xu, Ying; Hubal, Elaine A Cohen; Clausen, Per A; Little, John C

    2009-04-01

    A two-room model is developed to estimate the emission rate of di-2-ethylhexyl phthalate (DEHP) from vinyl flooring and the evolving gas-phase and adsorbed surface concentrations in a realistic indoor environment. Because the DEHP emission rate measured in a test chamber may be quite different from the emission rate from the same material in the indoor environment the model provides a convenient means to predict emissions and transport in a more realistic setting. Adsorption isotherms for phthalates and plasticizers on interior surfaces, such as carpet, wood, dust, and human skin, are derived from previous field and laboratory studies. Log-linear relationships between equilibrium parameters and chemical vapor pressure are obtained. The predicted indoor air DEHP concentration at steady state is 0.15 microg/m3. Room 1 reaches steady state within about one year, while the adjacent room reaches steady state about three months later. Ventilation rate has a strong influence on DEHP emission rate while total suspended particle concentration has a substantial impact on gas-phase concentration. Exposure to DEHP via inhalation, dermal absorption, and oral ingestion of dust is evaluated. The model clarifies the mechanisms that govern the release of DEHP from vinyl flooring and the subsequent interactions with interior surfaces, airborne particles, dust, and human skin. Although further model development, parameter identification, and model validation are needed, our preliminary model provides a mechanistic framework that elucidates exposure pathways for phthalate plasticizers, and can most likely be adapted to predict emissions and transport of other semivolatile organic compounds, such as brominated flame retardants and biocides, in a residential environment.

  18. Sequencing and comparative genome analysis of two pathogenic Streptococcus gallolyticus subspecies: genome plasticity, adaptation and virulence.

    Directory of Open Access Journals (Sweden)

    I-Hsuan Lin

    Full Text Available Streptococcus gallolyticus infections in humans are often associated with bacteremia, infective endocarditis and colon cancers. The disease manifestations are different depending on the subspecies of S. gallolyticus causing the infection. Here, we present the complete genomes of S. gallolyticus ATCC 43143 (biotype I and S. pasteurianus ATCC 43144 (biotype II.2. The genomic differences between the two biotypes were characterized with comparative genomic analyses. The chromosome of ATCC 43143 and ATCC 43144 are 2,36 and 2,10 Mb in length and encode 2246 and 1869 CDS respectively. The organization and genomic contents of both genomes were most similar to the recently published S. gallolyticus UCN34, where 2073 (92% and 1607 (86% of the ATCC 43143 and ATCC 43144 CDS were conserved in UCN34 respectively. There are around 600 CDS conserved in all Streptococcus genomes, indicating the Streptococcus genus has a small core-genome (constitute around 30% of total CDS and substantial evolutionary plasticity. We identified eight and five regions of genome plasticity in ATCC 43143 and ATCC 43144 respectively. Within these regions, several proteins were recognized to contribute to the fitness and virulence of each of the two subspecies. We have also predicted putative cell-surface associated proteins that could play a role in adherence to host tissues, leading to persistent infections causing sub-acute and chronic diseases in humans. This study showed evidence that the S. gallolyticus still possesses genes making it suitable in a rumen environment, whereas the ability for S. pasteurianus to live in rumen is reduced. The genome heterogeneity and genetic diversity among the two biotypes, especially membrane and lipoproteins, most likely contribute to the differences in the pathogenesis of the two S. gallolyticus biotypes and the type of disease an infected patient eventually develops.

  19. Bends and splitters in graphene nanoribbon waveguides

    DEFF Research Database (Denmark)

    Zhu, Xiaolong; Yan, Wei; Mortensen, N. Asger

    2013-01-01

    We investigate the performance of bends and splitters in graphene nanoribbon waveguides. Although the graphene waveguides are lossy themselves, we show that bends and splitters do not induce any additional loss provided that the nanoribbon width is sub-wavelength. We use transmission line theory...

  20. A study of the deformation and failure mechanisms of protective intermetallic coatings on AZ91 Mg alloys using microcantilever bending

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Mingyuan; Mead, James; Wu, Yueqin; Russell, Hugh; Huang, Han, E-mail: han.huang@uq.edu.au

    2016-10-15

    In this study, a nanoindentation-based microcantilever bending technique was utilized to investigate the interfacial properties of a β-Mg{sub 17}Al{sub 12}/AZ91 Mg alloy film/substrate system under tensile loading conditions. Finite element analysis (FEA) was first undertaken to optimise the design of cantilever structures for inducing high tensile stresses at the interface. Cantilevers consisting of a necked region or notch at the interface were determined to be the most successful designs. Microcantilevers containing the β-Mg{sub 17}Al{sub 12}/AZ91 interface were then made using focused ion beam (FIB) milling technique. Necks were made in the cantilevers to intensify the tension at the interface and notches were used to introduce a stress concentration to the interface. During bending, the cantilevers were deflected to failure. Subsequent analysis of the deformed cantilevers using electron microscopies revealed that plastic deformation, and subsequent ductile rupture, of the AZ91 phase was the dominant failure mechanism. When the β-Mg{sub 17}Al{sub 12}/AZ91 film/substrate system was subjected to tension, the softer AZ91 phase failed prior to interfacial delamination, demonstrating that the strength of the interface exceeded the stresses that caused ductile failure in the substrate material. - Highlights: •Microcantilever bending was used to study the property of film/substrate interface. •FEA was used to optimise cantilever design for achieving high interfacial tension. •The intermetallic coatings on AZ91 substrate have strong interfacial adhesion.