Simplified identification of material parameters for Yoshida-Uemori kinematic hardening model

Author(s):  
T. Phongsai ◽  
V. Uthaisangsuk ◽  
B. Chongthairungruang ◽  
S. Suranuntchai ◽  
S. Jirathearanat
2016 ◽  
Vol 725 ◽  
pp. 132-137
Author(s):  
Geun Su Joo ◽  
Hoon Huh

This paper is concerned with rate-dependent hardening behaviors of the TRIP980 steel sheet. In sheet metal forming, sheet metals experiences complicated loading at various strain rates. In order to predict deformed shape in sheet metal forming, accurate material properties and an appropriate constitutive model in numerical simulation are important to consider reverse loading and various strain rates simultaneously.This paper deals with rate-dependent material parameters of the isotropic/kinematic hardening model. Tension/compression tests of the TRIP980 steel sheet are performed with a newly developed experimental technique at various strain rates ranging from 0.001 to 100 s−1. Tension/compression hardening curves of the TRIP980 steel sheet are approximated by the Chun et al model at each strain rate condition respectively. From acquired material parameters, rate dependencies of tension/compression hardening behaviors are investigated.


Author(s):  
Runze Zhou ◽  
Ikuo Kojima ◽  
Takuyo Kaida ◽  
Hirokazu Tsuji

Fitness-for-service (FFS) assessments are quantitative engineering evaluations that perform to demonstrate the integrity of an in-service component that may contain a flaw or damage [1]. It can be used to make run-repair-replace decisions to help determine if pressured equipment containing flaw that have been identified by inspection can continue to operate safety for some period of time. This paper provides a FFS assessment on carbon steel pipe which contained a LTA (Local Thin Area) against seismic load by FEM (Finite Element Method) analysis. ABAQUS Ver. 6.10, which has the combined isotropic / kinematic hardening model [2], is used to simulate the LTA contained carbon steel pipe against seismic load. Material parameters in the hardening model are identified by a symmetric strain cycle experiment based on ASTM E606. Isotropic hardening component is introduced by specifying the equivalent stress defining the size of the yield surface, as a tabular function of the equivalent plastic strain. Kinematic hardening component is obtained from the stabilized cycle of a specimen that is subjected to symmetric stain cycles. The authors introduced the way how to calibrate the material parameters of combined isotropic / kinematic hardening model. Then the authors calculated up to 100 cycles on carbon steel pipe which contained a Local Thin Area against seismic load at 300 degrees centigrade. The results comparison between FEM analysis and experiment shows that stress-strain hysteresis loop tendency and number of cycles to failure are predicted accurately.


2001 ◽  
Vol 123 (3) ◽  
pp. 287-292 ◽  
Author(s):  
K. M. Zhao ◽  
J. K. Lee

The main objective of this paper is to simulate springback using a combined kinematic/isotropic hardening model. Material parameters in the hardening model are identified by an inverse method. A three-point bending test is conducted on 6022-T4 aluminum sheet. Punch stroke, punch load, bending strain, and bending angle are measured directly during the tests. Bending moments are then computed from these measured data. Bending moments are also calculated based on a constitutive model. Material parameters are identified by minimizing the normalized error between two bending moments. A micro genetic algorithm is used in the optimization procedure. Stress-strain curves are generated with the material parameters found in this way, which can be used with other plasticity models. ABAQUS/Standard, which has the combined isotropic/kinematic hardening model, is used to simulate draw-bend of 6022-T4 aluminum sheet. Absolute springback angles are predicted very accurately.


2000 ◽  
Author(s):  
K. M. Zhao ◽  
J. K. Lee

Abstract The main objective of this paper is to generate cyclic stress-strain curves for sheet metals so that the springback can be simulated accurately. Material parameters are identified by an inverse method within a selected constitutive model that represents the hardening behavior of materials subjected to a cyclic loading. Three-point bending tests are conducted on sheet steels (mild steel and high strength steel). Punch stroke, punch load, bending strain and bending angle are measured directly during the tests. Bending moments are then computed from these measured data. Bending moments are also calculated based on a constitutive model. Normal anisotropy and nonlinear isotropic/kinematic hardening are considered. Material parameters are identified by minimizing the normalized error between two bending moments. Micro genetic algorithm is used in the optimization procedure. Stress-strain curves are generated with the material parameters found in this way, which can be used with other plastic models.


2020 ◽  
Vol 10 (8) ◽  
pp. 2834
Author(s):  
Mohsen Saleh Asheghabadi ◽  
Xiaohui Cheng

In this study, a soil–tunnel model for clay under earthquake loading is analyzed, using finite element methods and a kinematic hardening model with the Von Mises failure criterion. The results are compared with those from the linear elastic–perfectly plastic Mohr–Coulomb model. The latter model does not consider the stiffness degradation caused by imposing cyclic loading and unloading to the soil, whereas the kinematic hardening model can simulate this stiffness degradation. The parameters of the kinematic hardening model are calibrated based on the results of experimental cyclic tests and finite element simulation. Here, two methods—one using data from cyclic shear tests, and the other a new method using undrained cyclic triaxial tests—are used to calibrate the parameters. The parameters investigated are the peak ground acceleration (PGA), tunnel lining thickness, tunnel shape, and tunnel embedment depth, all of which have an effect on the resistance of the shallow tunnel to the stresses and deformations caused by the surrounding clay soils. The results show that unlike traditional models, the nonlinear kinematic hardening model can predict the response reasonably well, and it is able to create the hysteresis loops and consider the soil stiffness degradation under the seismic loads.


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