Basic Formulations for Elastoplastic Constitutive Equations

Abstract

Elastic deformation is induced microscopically by the elastic deformations of the material particles themselves, exhibiting a one-to-one correspondence to the stress. However, when the stress reaches an yield stress, slippages between material particles are induced, which do not disappear even if the stress is removed, leading to macroscopically to the plastic deformation. Then, the one-to-one correspondence between the stress and the strain, i.e. the stress-strain relation does not hold in the elastoplastic deformation process.