Internal variables and phenomenological models for metals plasticity

2014 This paper aims towards a presentation of the general structure of the phenomenological models presently used for the macroscopic description of metal plasticity and a discussion of their interaction with microstructural investigation. Attention is concentrated on internal variables modelization which, from the very beginning, must include some ideas about the microstructural material state. After a presentation of the basic mechanical and thermodynamical framework, the classical models will be described through the usual internal variables, the associated thermodynamic forces and the microstructural features they are supposed to take into account. Some approaches will then be presented to give a deeper microstructural content to these models. A distinction will be made between micromechanical approaches and qualitative use of microstructural informations. This methodological discussion will be illustrated by some recent works and models, and concluded by some examples showing the necessity to combine these two approaches. The concept of internal stress will also be discussed. As a conclusion the need for an increasing interaction between the mechanics and physics of materials will be advocated. Revue Phys. Appl. 23 (1988) 649-659 AVRIL 1988, Classification