General Kinematic-Isotropic Hardening Model

Abstract

This paper first points out that an evolution rule of the yield center without a motion component in the plastic strain rate direction leads to ratchetting, while an evolution rule with such a component motion leads to proportional material response. The paper then successfully tackles such a dilemma by proposing a general kinematic-isotropic hardening model that is able to control the yield center motion and to allow the radius of the yield surface to evolve arbitrarily as needed. Theoretical analysis shows that this model is capable of describing all the possible material responses. With a plastic modulus also proposed in the paper, an example is then given to show that the theoretical prediction compares very well with the ratchetting test.