Thermal and Creep Effects in Work-Hardening Elastic-Plastic Solids

Abstract

EXTREMUM PRINCIPLES GOVERNING the isothermal deformation of a work-hardening elastic-plastic solid have been given by Hodge and Prager and Hill. In the present note it is shown how these principles can be extended to include thermal and creep effects. Using rectangular Cartesian coordinates xt (i = 1, 2, 3), denote the infinitesimal displacement from the s tandard state by uh the infinitesimal strain by eij} the stress by aij} the mean normal stress by a, and the stress deviation by s y . The mean normal stress is defined as