A Bounding Surface Theory for Cyclic Thermoplasticity

Abstract

A nonisothermal, rate and time independent generalization of nonlinear kinematic hardening theory for cyclic plasticity is introduced. The model includes decomposition of backstress and of isotropic hardening between the yield surface radius and the backstress amplitude. A purely temperature dependent component of yield surface radius is assumed in addition to an isotropic hardening component. Issues of thermoplastic material stability and temperature history independence are clearly distinguished and addressed via implications of temperature rate terms. Correlations are reported for OFHC copper subjected to thermomechanical cyclic loading.