COMPARISON OF SOME PLASTICITY THEORIES BY MEANS OF THE FINITE ELEMENT METHOD

Abstract

This paper deals with six plasticity theories by means of finite element method. These are the time-independent theory of Prandtl-Reuss, Hencky-Nadai, Ilyushin and Valanis and the elasto-viscoplastic theory of Perzyna and Krempl. The stress-strain relation in the plasticity theories investigated is written uniformly in incremental form. The time-independent theories are compared by computing the deformation of a thin- walled tube subjected to combined tension-torsion. The two elasto-viscoplastic theories are applied to a thick-walled cylinder subjected to a pressurization rate of 1 Mpa/s. The hoop stress distribution is presented.