Results Of Elastic-plastic Analysis Research Articles

Elastic-Plastic Thermal and Residual Stress Analysis of Adhesively Bonded Single Lap Joint

In this work, an elastic-plastic thermal and residual stress analysis were performed for adhesively bonded single lap joint. For this purpose, thermoplastic composite adherents were bonded to each other with epoxy adhesive. Thermoplastic composite material was reinforced by steel-fibres, unidirectionally. Finite element method (FEM) was preferred to obtain thermal elastic and elastic-plastic stress distributions on single lap joint. Accordingly, modelling and solution processes were achieved using ANSYS software. So as to determine effects of uniform temperature loadings on thermal and residual stresses, different values of it were loaded on the joint, uniformly. Briefly, both thermal and residual thermal stresses were calculated under uniform temperature loading which was selected from 40 °C to 80 °C. According to obtained results different thermal expansion coefficients of composite adherents and adhesive layer caused thermal and residual stresses on adhesively bonded single lap joint due to applied uniform temperature loadings. Thermal stress values for x and y-directions are very different from each other owing to orthotropic material properties of thermoplastic composite. The magnitudes of elastic analyses results are higher than elastic-plastic analysis results. Contrary to elastic analysis results, elastic-plastic analysis results were nonlinear. Thermal and residual stresses are increased by increasing uniform temperature values, so the highest values were calculated when 80 °C. The plastic yielding was firstly come into being for 50 °C loading and it is expanded related to raising thermal loadings as nonlinear.

Preliminary analysis for thermal-fatigue test of HIP joined W and ferritic-martensitic steel mockup

For the application to plasma facing component (PFC) in a fusion reactor, joining methods between tungsten (W) and ferritic-martensitic steel (FMS) have been developed and three W/FMS mockups were fabricated by HIP (hot isostatic pressing) joining method. Because the high heat flux test should be performed over the thermal lifetime of the mockup to confirm the integrity of joining technology, test conditions are found by performing a thermal-hydraulic and thermo-mechanical analysis with the conventional codes such as ANSYS-CFX and ANSYS-mechanical, respectively. From the analysis, the heating and the cooling conditions are determined, for 1.0MW/m2 heat flux, to be 30s heating and 30s cooling with given test facility cooling system. And the test cycle number for thermal-fatigue testing is determined to be 2500 cycles because the estimated thermal-lifetime of the mockup is about 2324 cycles from the results of elastic-plastic analysis. The high heat flux test with KoHLT-EB will be performed with these test conditions in the near future.

The Application of ABAQUS in Cast-Steel Joints Elastic-Plastic Analysis

The article introduces the application of the large universally used finite element analysis software ABAQUS in elastic-plastic analysis of the cast-steel joints in building structure. Using the cast-steel joint of a large reticulated shell structure in Shenzhen as an example, the article explains how to import the joint model into ABAQUS and start the finite element analysis, and finally get the elastic-plastic analysis results, thus provide the reference for engineering design, analysis and optimize design of cast-steel joints.

Analysis on Energy-Consumption and Earthquake-Mitigation for a High-Rise Building Set Metal Yield Dampers

Based on the mechanical properties of metal yield damper, high-rise residential building is implemented elastic-plastic response analysis for structure by using the nonlinear dynamic time-history analysis method under the effect of M8-class strong earthquake ,and judge performance level of structure and component. According to the elastic-plastic analysis results, put forward the improvement proposal for design to make the structure have the better resistance performance against the earthquake.

Analysis of Hydrogen Diffusion in Notched High-Strength Steel Wires

Fick's laws were used to model the hydrogen diffusion in notched high-strength steel wires loaded in tension under elastic-plastic conditions. The plastic deformation at the notch tip has an effect on the peak distribution of the hydrostatic stress ( h σ ). So, in stress-assisted diffusion analysis, elastic-plastic material behavior should be considered. Coupled diffusion elastic-plastic finite element analysis was implemented in the finite element program ABAQUS using the user element subroutine (UEL) and the coupled temperature-displacement solver routine to solve the variational form of the diffusion equation in order to obtain the hydrogen concentration distribution ahead of the notch tip in high-strength steel wires under plane strain conditions. The analysis results are compared with those obtained from elastic analysis, which shows that, if a critical hydrogen concentration is regarded as a local fracture criterion, the elastic-plastic analysis results can be used to evaluate the hydrogen embrittlement of high-strength steel wires.

引張荷重を受ける傾斜き裂板の座屈特性−弾塑生解析および実験検証

A cracked plate under tension could manifest a local buckling along the crack due to a compressive stress field in the crack’s vicinity. Crack length and location, loading condition, as well as aspect ratio, thickness, and overall dimensions of the plate are among the contributing parameters to the local buckling characteristics. In this study, the buckling characteristics of a cracked plate on whick the crack’s orientation is not perpendicular to the tensile loading were xs examined. Elastic-plastic buckling analyses of a plate with an oblique crack were conducted by taking into account the effect of the plasticity of the crack tip regions on the local buckling. The elastic-plastic analysis results were compared with experimental results as well as with an elastic buckling analysis. This study reveals that the oblique angle of the crack contributes significantly to the characteristics of the buckling behavior.

A thermal elastic-plastic finite-element analysis to roll-life prediction on the twin roll strip continuous casting process

The rolling force and roll deformation behavior in the twin-roll-type strip continuous casting process have been computed to estimate the thermal characteristics of a caster roll. To calculate the rolling force, the relationship between the flow stress and strain for a roll material and a casting alloy are assumed as a function of the strain rate and temperature, because the mechanical properties of casting materials depend on temperature. The three-dimensional (3-D) thermal elastic-plastic analysis of a cooling roll has also been carried out, to obtain roll stress and plastic strain distributions, with the commercial finite-element analysis package of ANSYS. Temperature field data for a caster roll, provided by the authors, were used to estimate the roll deformation. Therfore, numerical models considering the thermal and rolling forces have been developed to estimate the roll life. Roll life considering the thermal cycle is calculated using thermal elastic-plastic analysis results. The roll life is proposed in terms of roll revolution in the caster roll models with and without the fine crack failure on the roll surface. To obtain plastic strain distributions of the caster roll, thermomechanical properties of a roll sleeve with a copper alloy are obtained by a uniaxial tensile test for variation of temperature. The proposed analysis techniques have improved in caster roll design.

Concepts of plasticity in solenoid stress analysis

The concepts of plasticity are reviewed in the context of solenoid magnet design. The von Mises and Hill yield functions are introduced and related to flow rules. The derivation of equations for an elastic-plastic analysis of solenoids is discussed. Material properties are derived from Nb/sub 3/Sn conductors and used in example calculations. The results of elastic-plastic analyses are compared with those of elastic analyses under various assumptions.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

軸力及び繰返し曲げを受け耐力低下を生じる柱の変形累積の安定性

In order to obtain the basis for the limitation of the constant external forces to ascertain the aseismic safety of structures and their members, the accumulation of deformation and strength deterioration were investigated analytically for three-element models The theoretical solutions of the axial force at the boundary that the accumulation of the strain converges and tthat the beamcolumn collapses were derived under a certain value of the centroidal axial strain, and were compared with the results of elastic-plastic analyses

ＳＵＳ３０４鋼切欠き平板の曲げクリープ・疲労下の変形挙動および寿命評価法の検討

Creep-fatigue tests were carried out on notched plates under cyclic bending loads out of plane at 550°C, and the local strain at the notch-root and micro crack propagation behavior were measured. Then, inelastic analysis was performed for the experiment by using three kinds of constitutive models, such as kinematic hardening, ORNL and Ohno models. From the comparison of the experiment with the results of analysis, the following conclusions were obtained.(1) Creep strain caused at the notch-root during load holding was negligibly small compared with plastic strain, so that the neighborhood of the notch-root is subjected to constrained strain type damage.(2) The strain range at the notch-root can be calculated from the results of elastic-plastic analysis for monotonic loading independent of the constitutive models used, where the cyclic stress-strain relationship was used as the material monotonic deformation property.(3) The mean strain calculated was consistent with the experimental value in case of kinematic hardening or ORNL model, while not in case of Ohno model.(4) A method for predicting the crack initiation life of a notched plate has been proposed on the basis of micro-crack propagation behavior obtained by a fundamental creep-fatigue test.

長期設計荷重下におけるRC造スラブの鉄筋の抜出しに関する解析的研究

As one of the factors which influence long-term deflections on reinforced concrete slabs after being cracked, the slippage of tension steel at fixed edges has been generally accepted. From previously published test data, it is obvious that the influence on the slippage of tension steel is so large that it can not be disregared when compared with the influence on creep and shrinkage of concrete. However, a method for the quantitative estimation on the change of slippage of tension steel with time is still not clear. In this paper, the formulation is shown on the basis of bond stress-relative slippage relation and then the validity of this formulation is examined by comparing analayzed results with experimental results. Finally, even though equations solved by elastic analysis are used as the equation for the calculation of the slippage of tension steel under sustained design loading, it is shown that the analyzed results which are given by these equations are sufficiently useful for structural design when the results of elastic analysis are compared with the results of elastic-plastic analysis. Furthermore, it is shown that L=35 d may be used as the anchorage length in the case of utilizing a calculated equation for the slippage of tension steel on pull-out specimens.

Post-buckling behavior of centrally cracked plates under tension.

The post-buckling behavior of centrally cracked rectangular plates subjected to a uniaxial tension is analyzed by the finite element method, taking into account both geometrical and material nonlinearities. The finite element formulation is based on the total Lagrangian coordinate system and the flow theory of plasticity. The effects of an initial imperfection on buckling deformation are studied in some detail. Post-buckling behavior is discussed in relation to undesirable effects on the fracture of cracked plates. The results of elastic analyses show that the magnitude of the stress intensity factor increases after buckling. The results of elastic-plastic analyses and experiments show that the residual strength of cracked plates is reduced by the interaction between buckling deformation and plastic deformation at the end of cracks.