A Cyclic Plasticity Model without Yield Surface

In this study after reviewing classical cyclic plasticity models a generalized format of these existing cyclic plasticity models is presented. Using this unique format, the governing relation between stress and strain in deviatoric space can be expressed as two similar equations. The plastic constitutive equation of the model is based on two parameters DP and eint. The first parameter is a scalar function of the material status and the second one is internal strain parameter representing hardening rule. Most of the reviewed models will be presented based on these two parameters. Given this unified formulation, a cyclic plasticity model with no reference to yield surface is described. Different materials under a variety of load paths are considered and solved using the new model. The results agree well with available experimental results.

Keywords:

Cyclic plasticity , Yield surface , Non-proportional loading