On the evolution of plasticity and incompatibility

The phenomenological theory of elastic-plastic response is reconsidered in the light of recent opinion regarding the constitutive character of the constituent elastic and plastic deformations. The primary role of dissipation in the physics of plastic evolution is emphasized and shown to lead to the clarification of a number of open questions. Particular attention is given to the invariance properties of the elastic and plastic deformations, to the kinematics of discontinuities, and to the role of material symmetry in restricting constitutive equations for elastic response, yield and plastic evolution.