A CONSTITUTIVE INEQUALITY IN PLASTICITY INVOLVING LEFT-HAND AND RIGHT-HAND RATES

An incremental inequality was given by Pouya (1993) for the study of the rate discontinuities of elastoplastic materials. It will be shown here that this inequality can be considered as a general postulate for standard elastoplastic materials. This inequality unifies the three postulates of the symmetry of the elastic compliance tenser, the normality flow rule, and, for models with a hardening matrix, the local symmetry of this matrix. A stronger interpretation of this inequality contains also the local convexity of the elastic domain.