Update of Conventional and Unconventional Plastic Response and Representation

Abstract

The primary purpose of this update is to outline progress that has been made in three directions: 1) exhibiting the real but limited instability of configuration and instability of path for loaded homogeneous specimens of a material model that obeys a non-associated flow rule; 2) exploring the roles of inhomogeneity of material and of stress as explanations for the suitability of idealizing the macroscopic plastic behavior of most structural metals and alloys as stable and time-independent over much of their range of use, despite possible instability on the miniscale and the always-present strong instability and time-dependence on the microscale; and 3) the search for a clearer picture of the likely relation of macroscopic flow stress to properties of dislocation arrays and barrier regions. Other topics, touched upon very briefly, include: finite elastoplasticity, the application of thermodynamics, and the increasing variety of non-traditional or unconventional formulations.