Study of Integration Strategy for Thermal-Elastic-Plastic Models

Abstract

The accuracy of a new integration algorithm is examined for a von Mises-type model of thermal-elastic-plasticity with nonlinear, mixed isotropic-kinematic hardening. The algorithm is founded on the frame of an integral representation of the conventional rate constitutive equations in contrast to the conventional rate equations themselves. The thermal effect on the yield surface is built in this approach without any difficulty. Under a generalized assumption of a constant strain rate, the model can be reduced to two scalar first-order ordinary differential equations which make an error-controllable integration method possible. Furthermore, for a nonconstant strain rate, e.g., a linear strain rate, the same idea of derivation achieves a similar conclusion. Errors of single-step stress predictions for given total strain increments are discussed.