Comparative Study on the Nonlinear Calculation of Ratcheting Deformation Using Different Constitutive Model

2020 ◽  
Author(s):  
Xuejiao Shao ◽  
Hai Xie ◽  
Furui Xiong ◽  
Xiaolong Fu ◽  
Kaikai Shi ◽  
...  
Keyword(s):  
Plastic Strain ◽  
Constitutive Model ◽  
Kinematic Hardening ◽  
Constitutive Models ◽  
Fatigue Analysis ◽  
Constitutive Law ◽  
Elastic Plastic ◽  
Bending Strain ◽  
Cumulative Strain ◽  
Membrane Strain

Abstract In the fatigue assessment of nuclear components following the RCC-M B3200, if the results using the simplified elastic-plastic method cannot meet the Code’s requirements, it is necessary to conduct a detailed elastic-plastic fatigue analysis of the component. In this paper, the A-F and Chaboche nonlinear kinematic hardening constitutive models are used to conduct an elasto-plastic fatigue analysis for a typical nozzle component, aiming to calculate the secondary cumulative cyclic plastic strain of the structure induced by the rapid temperature change transient. The calculation method of nonlinear ratcheting behavior under cyclic loading is studied. The method of determining the parameters of constitutive model based on cyclic stable stress-strain curve is also studied. A sensitive study of the parameters for the same constitutive law is presented, including the results of cumulative plastic strain. The ratcheting behavior simulation calculated by different constitutive models are compared. The results show that the A-F model has a conservative prediction of ratcheting behavior as the dynamic recovery term is too strong. It was found that the Chaboche constitutive model is the better methodology for ratcheting analysis. In order to evaluate the bearing ability of the section, the membrane strain and bending strain is obtained by linearizing the node strain along the cross section. The ratios of membrane strain and membrane plus bending strain to total strain are calculated, which is helpful to determining the limit criteria for the cumulative strain of structures.

Comparison of Different Constitutive Models in Sheet Metal Forming

2013 ◽  
Vol 554-557 ◽  
pp. 1203-1216 ◽  
Author(s):  
Meriç Uçan ◽  
Haluk Darendeliler
Keyword(s):  
Constitutive Model ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Kinematic Hardening ◽  
Piecewise Linear ◽  
Constitutive Models ◽  
Isotropic Hardening ◽  
Anisotropic Plasticity ◽  
Elastic Plastic

The effects of different constitutive models in sheet metal forming are investigated by considering the cylindrical and square cup drawing and V-bending processes. Numerical analyses are performed by employing eight different constitutive models. These are elastic plastic constitutive model with isotropic hardening, elastic plastic constitutive model with kinematic hardening, elastic plastic constitutive model with combined hardening, power law isotropic plasticity, piecewise linear isotropic plasticity, three-parameter Barlat, anisotropic plasticity and transversely anisotropic elastic plastic models. The simulations are performed for three different materials, St12 steel, Al-5182 aluminum and stainless steel 409 Ni, by using a commercial finite element code. A number of experiments are carried out and the experimental and analytical results are utilized to evaluate the results of simulations.

The Elastic-Plastic Analysis of Tubes—IV: Thermal Ratchetting

1992 ◽  
Vol 114 (2) ◽  
pp. 236-245 ◽  
Author(s):  
W. Jiang
Keyword(s):  
Steady State ◽  
Plastic Strain ◽  
Centrifugal Force ◽  
Kinematic Hardening ◽  
Elastic Plastic ◽  
External Pressures ◽  
Plastic Analysis ◽  
Steady Solutions ◽  
Number Of Cycles

This paper continues the investigation of the shakedown behavior of tubes subjected to cyclic centrifugal force and temperature, and sustained internal and external pressures. It is found that when ratchetting occurs, the plastic strain builds up with each cycle, but finally reaches a steady state after a large number of cycles for kinematic hardening materials. The steady solutions for three kinds of ratchetting behavior are found and given in this paper.

Bodner-Partom Constitutive Model and Nonlinear Finite Element Analysis

1990 ◽  
Vol 112 (3) ◽  
pp. 287-291 ◽  
Author(s):  
F. A. Kolkailah ◽  
A. J. McPhate
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Plastic Strain ◽  
Constitutive Model ◽  
Finite Element Model ◽  
Numerical Technique ◽  
Element Model ◽  
Material Behavior ◽  
Model Parameters ◽  
Elastic Plastic

In this paper, results from an elastic-plastic finite-element model incorporating the Bodner-Partom model of nonlinear time-dependent material behavior are presented. The parameters in the constitutive model are computed from a leastsquare fit to experimental data obtained from uniaxial stress-strain and creep tests at 650°C. The finite element model of a double-notched specimen is employed to determine the value of the elastic-plastic strain and is compared to experimental data. The constitutive model parameters evaluated in this paper are found to be in good agreement with those obtained by the other investigators. However, the parameters determined by the numerical technique tend to give response that agree with the data better than do graphically determined parameters previously used. The calculated elastic-plastic strain from the model agreed well with the experimental strain.

An Expression of Elastic-Plastic Constitutive Law Incorporating Vertex Formation and Kinematic Hardening

1991 ◽  
Vol 58 (3) ◽  
pp. 617-622 ◽  
Author(s):  
Moriaki Goya ◽  
Koichi Ito
Keyword(s):  
Kinematic Hardening ◽  
Sufficient Conditions ◽  
Constitutive Law ◽  
Elastic Plastic ◽  
Hardening Rule ◽  
Direction Angle ◽  
Plastic Materials ◽  
Path Direction ◽  
Elastic Plastic Materials ◽  
Linear Loading

A phenomenological corner theory was proposed for elastic-plastic materials by the authors in the previous paper (Goya and Ito, 1980). The theory was developed by introducing two transition parameters, μ (α) and β (α), which, respectively, denote the normalized magnitude and direction angle of plastic strain increments, and both monotonously vary with the direction angle of stress increments. The purpose of this report is to incorporate the Bauschinger effect into the above theory. This is achieved by the introduction of Ziegler’s kinematic hardening rule. To demonstrate the validity and applicability of a newly developed theory, we analyze the bilinear strain-path problem using the developed equation, in which, after some linear loading, the path is abruptly changed to various directions. In the calculation, specific functions, such as μ (α) = Cos (.5πα/αmax) and β (α) = (αmax- .5π) α/αmax, are chosen for the transition parameters. As has been demonstrated by numerous experimental research on this problem, the results in this report also show a distinctive decrease of the effective stress just after the change of path direction. Discussions are also made on the uniqueness of the inversion of the constitutive equation, and sufficient conditions for such uniqueness are revealed in terms of μ(α), β(α) and some work-hardening coefficients.

Modeling the Ratcheting Phenomenon in an Austenitic Steel at Room Temperature

2000 ◽  
Author(s):  
A. S. Zaki ◽  
H. Ghonem
Keyword(s):  
Plastic Strain ◽  
Constitutive Model ◽  
Austenitic Steel ◽  
Room Temperature ◽  
Polycrystalline Material ◽  
Kinematic Hardening ◽  
Experimental Results ◽  
Experimental Program ◽  
Model Parameters ◽  
Proposed Model

Abstract This paper describes the cyclic accumulative plastic strain in a polycrystalline material when subjected to loading conditions promoting ratcheting behavior. For this purpose, a unified viscoplastic constitutive model based on non-linear kinematic hardening formulation is implemented. Identification of the model parameters was carried out using an experimental program that included monotonic, cyclic and relaxation testing. Simulation of the material response using the proposed model is compared with experimental results for the same loading. This comparison is used to evaluate the model validity.

Development of Elastic-Plastic Constitutive Models for the Evaluation of Nuclear Piping Systems Under Severe Cyclic Loading

2012 ◽  
Author(s):  
Yukio Takahashi ◽  
Yoshihiko Tanaka
Keyword(s):  
Cyclic Loading ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Kinematic Hardening ◽  
Constitutive Models ◽  
Seismic Loading ◽  
Piping System ◽  
Elastic Plastic ◽  
Piping Systems

It is essential to predict the behavior of nuclear piping system under seismic loading to evaluate the structural integrity of nuclear power plants. Relatively large stress cycles may be applied to the piping systems under severe seismic loading and plastic deformation may occur cyclically in some portion of the systems. Accurate description of inelastic deformation under cyclic loading is indispensable for the precise estimation of strain cycles and accumulation potentially leading to the failure due to fatigue-ratcheting interaction. Elastic-plastic constitutive models based on the nonlinear kinematic hardening rule proposed by Ohno and Wang were developed for type 316 austenitic stainless steel and carbon steel JIS STPT410 (similar to ASTM A106 Gr.B), both of which are used in piping systems in nuclear power plants. Different deformation characteristics under cyclic loading in terms of memory of prior hardening were observed on these two materials and they were reflected in the modeling. Results of simulations under various loading conditions were compared with the test data to demonstrate the high capability of the constitutive models.

Study on the Constitutive Model of Composite Materials in Elastic-Plastic Stage

2012 ◽  
Vol 166-169 ◽  
pp. 73-77
Author(s):  
Huan Chao Qin ◽  
Ju Lin Wang
Keyword(s):  
Composite Materials ◽  
Theoretical Analysis ◽  
Plastic Strain ◽  
Constitutive Model ◽  
Experimental Results ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Flexibility Matrix ◽  
Plastic Stage

Elastic-plastic properties of composite materials are an important part of the study on micromechanics. Based on the plastic strain of matrix, the elastic-plastic constitutive model of composite materials is presented in this paper, while considering the influence of the transient flexibility matrix on the flexibility matrix. In comparison with the experimental results, theoretical analysis of the presented model is validated.

Non-Coaxial Plasticity Constitutive Modeling of Sands

2013 ◽  
Vol 684 ◽  
pp. 150-153 ◽  
Author(s):  
Ping Hu ◽  
Mao Song Huang ◽  
Deng Gao Wu
Keyword(s):  
Plastic Strain ◽  
Constitutive Model ◽  
Principal Stress ◽  
Three Dimensional ◽  
Constitutive Models ◽  
Strain Increment ◽  
Stress Axis ◽  
Shear Tests ◽  
Plastic Strain Increment ◽  
Principal Axes

Classical coaxial plasticity constitutive models implicate an inevitable limitation that directions for principal stress and that for principal plastic strain increment are always coaxial. They are not capable of simulating non-coaxial phenomena during the rotation of principal stress axis. In this paper, a three-dimensional, non-coaxial plasticity constitutive model for sands with a modification of Lade angle dependent shape function is introduced to describe the non-coaxial behavior under principal axes rotation. A series of numerical simulations of hollow cylindrical torsional shear tests are performed. The results show that the proposed constitutive model can predict the variations of principal plastic strain increment directions with principal stress directions reasonably.

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