Consistent tangent operator for plasticity models based on the plastic strain rate potential

A stress updating integration algorithm is derived for use with plastic strain rate potentials and with the backward implicit Euler method. An explicit expression is also deduced for the consistent tangent modulus. This analysis extends an earlier treatment developed for elastic-perfectly plastic materials in that it applies to materials which harden isotropically. The method is intended for use in finite element calculations that employ plasticity models based on the plastic strain rate potential. It is particularly suitable for cases where the form of the plastic dual potential has been obtained from texture measurements or from crystallographic models that describe texture evolution during metal forming.