Constitutive Law of Finite Deformation Elastoplasticity With Proportional Loadings

Abstract

In this paper, decomposition of the total strain into elastic and plastic parts is investigated for extension of elastictype constitutive models to finite deformation elastoplasticity. In order to model the elastic behavior, a Hookeantype constitutive equation based on the logarithmic strain is considered. Based on this constitutive equation and assuming the deformation theory of Hencky as well as the yield criteria of von Mises, the elasticplastic behavior of materials at finite deformation is modeled in the case of the proportional loading. Moreover, this elastoplastic model is applied in order to determine the stress distribution in thickwalled cylindrical pressure vessels at finite deformation elastoplasticity.