Mechanics of the inelastic behavior of materials - Part 1, theoretical underpinnings

This is the first of a two-part paper that is concerned with the modeling of the behavior of inelastic materials from a continuum viewpoint, taking into account changes in the elastic response and material symmetry that occur due to changes in the microstructure of the material. The first part discusses some of the fundamental issues that must be addressed when modeling the elastic response of these materials. In particular, we discuss in detail the far reaching effects of the notion of materials with families of elastic response functions with corresponding natural configurations that was introduced by Wineman and Rajagopal (1990, Archives of Mechanics, 42, 53-75) and Rajagopal and Wineman (1992, Int. J. Plasticity 8, 385-395) for the study of the inelastic behavior of polymeric materials and later generalized and extended to the study of deformation twinning of polycrystals by Rajagopal and Srinivasa (1995 Int. J. Plasticity 11(6), 653-678, 1997, 13(1/2) 1-35). For these materials, a definition of material symmetry is introduced, that makes it possible to discuss the concept of "evolving material symmetry". (C) 1998 Elsevier Science Ltd. All rights reserved.