ON A KINETIC FORMULATION OF ELASTOVISCOPLASTICITY

A kinetic formulation of elasto-viscoplasticity is proposed. It consis ts of a non-linear Maxwell-like viscoelastic constitutive equation (CE ) that describes the evolution of the recoverable (elastic) part of th e total Finger strain tensor, a thermodynamic formulation of stress te nsor dependence on the elastic strain tensor; and a kinetic equation f or a scalar ''bonding'' factor. The set of CEs does not contain any ma thematical yield criterion but predicts anisotropic yield values for s tress as a transition from solid-like deformations to flow through a b ifurcation. The set of CEs proposed is shown to be globally Hadamard s table. The dissipative stability is also discussed briefly. In the cas e when the elastic strains are sufficiently small, the second-order ap proach is developed. Within this approach, several problems of simple shearing are analyzed to illustrate the model behavior. Published by E lsevier Science Ltd