Elastic Potentials and the Structure of Inelastic Constitutive Laws

The existence of a work potential, governing material response when elastic behavior occurs, is shown to provide a concise framework for the structure of inelastic constitutive laws. The discussion includes the identification of differential invariants in conjugate stress and strain variables, an examination and reformulation of postulates leading to "normality rules", and a study of the transmission of constitutive properties from subelements to overall behavior of heterogeneous systems. Also, internal variable representations of inelasticity are examined within this framework.