On the applicability of generalized strain measures in large strain plasticity

Abstract

In the present paper two thermodynamically consistent large strain plasticity models are examined and compared in finite simple shear. The first model (A) is based on the multiplicative decomposition of the deformation gradient, while the second one (B) on the additive decomposition of generalized strain measures. Both models are applied to a rigid-plastic material described by a von Mises-type yield criterion. Since both models include neither a hardening nor a softening law, a constant shear stress response, even for large amounts of shear, is expected. Indeed, model A exhibits true constant shear stress behavior independent of the elastic material law. This is not, however, the case for model B so that its applicability under finite shear deformations may be questioned.