Rate-dependent isotropic‒kinematic hardening model in tension‒compression of TRIP and TWIP steel sheets

2018 ◽  
Vol 146-147 ◽  
pp. 432-444 ◽  
Author(s):  
Geunsu Joo ◽  
Hoon Huh
Author(s):  
Lallit Anand ◽  
Sanjay Govindjee

This chapter provides an introduction to combined isotropic-kinematic hardening plasticity models in the three-dimensional small strain setting. The additive decomposition of the strain is introduced along with the concepts of plastic strain, equivalent tensile plastic strain, and back stress for three-dimensional problems. Plastic flow is discussed and defined, and a complete model of plasticity is formulated with Kuhn-Tucker loading/unloading conditions. The kinematic hardening model is based upon the Armstrong-Fredrick evolution law. Both rate-independent and rate-dependent (viscoplastic) models are discussed.


Author(s):  
Shree Krishna ◽  
Tasnim Hassan

A set of cyclic and ratcheting experimental responses obtained under proportional to various degrees of nonproportional loading cycles are simulated using the modified Chaboche model in its rate-independent and rate-dependent forms. Features of the modified Chaboche nonlinear-kinematic hardening model needed for simulating cyclic hardening-softening, cyclic relaxation and ratcheting responses under uniaxial and multiaxial loading are elaborated. Significance of “rate-dependent” and novel “back stress shift” modeling features in improving the hysteresis loop and ratcheting rate simulations are demonstrated. Influence of the isotropic and kinematic hardening parameters in improving the multiaxial ratcheting response simulation by the modified Chaboche model are illustrated.


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.


2013 ◽  
Vol 22 (6) ◽  
pp. 303-309 ◽  
Author(s):  
S.C. Park ◽  
T. Park ◽  
Y. Koh ◽  
D.Y. Seok ◽  
T. Kuwabara ◽  
...  

1990 ◽  
Vol 57 (2) ◽  
pp. 298-306 ◽  
Author(s):  
K. W. Neale ◽  
S. C. Shrivastava

The inelastic behavior of solid circular bars twisted to arbitrarily large strains is considered. Various phenomenological constitutive laws currently employed to model finite strain inelastic behavior are shown to lead to closed-form analytical solutions for torsion. These include rate-independent elastic-plastic isotropic hardening J2 flow theory of plasticity, various kinematic hardening models of flow theory, and both hypoelastic and hyperelastic formulations of J2 deformation theory. Certain rate-dependent inelastic laws, including creep and strain-rate sensitivity models, also permit the development of closed-form solutions. The derivation of these solutions is presented as well as numerous applications to a wide variety of time-independent and rate-dependent plastic constitutive laws.


2001 ◽  
Vol 695 ◽  
Author(s):  
Y.-L. Shen ◽  
U. Ramamurty

ABSTRACTThe constitutive behavior of passivated copper films is studied. Stresses in copper films of thickness ranging from 1000 nm to 40 nm, passivated with silicon oxide on a quartz or silicon substrate, were measured using the curvature method. The thermal cycling spans a temperature range from - 196 to 600°C. It is seen that the strong relaxation at high temperatures normally found in unpassivated films is nonexistent for passivated films. The copper film did not show any rate-dependent effect over a range of heating/cooling rate from 5 to 25°C/min. Further analyses showed that significant strain hardening exists during the course of thermal loading. In particular, the measured stress- temperature response can only be fitted with a kinematic hardening model, if a simple constitutive law within the continuum plasticity framework is to be used. The analytic procedures for extracting the film properties are presented. Implications to stress modeling of copper interconnects in actual devices are discussed.


2017 ◽  
Vol 111 ◽  
pp. 9-18 ◽  
Author(s):  
Pundan K. Singh ◽  
Anindya Das ◽  
S. Sivaprasad ◽  
Pinaki Biswas ◽  
Rahul K. Verma ◽  
...  

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