On the evolution equation for the rest stress in rate-dependent plasticity

Three different structures of the evolution equation for the rest stress are derived. They correspond to different models of viscoplastic response, constructed by three-dimensional generalization of simple one-dimensional rheological models. Isotropic, kinematic and combined isotropic–kinematic hardening, with an evolution equation for the back stress, are incorporated in the constitutive framework. The results may be of interest in the analytical and numerical studies of the rate-dependent inelastic response.