The Extended Elastoplastic Constitutive Equation with Tangential Stress Rate Effect

The extension of the elastoplastic constitutive equation so as to describe the plastic stretching due to the stress rate component tangential to the yield or loading surface has been one of the most pressing problems in the elastoplasticity. To this aim, various models have been proposed in the past. However, a pertinent model applicable to a general loading process has not previously been proposed. In this article, the elastoplastic constitutive equation extended so as to describe a plastic stretching due to a stress rate component tangential to a yield or loading surface is formulated keeping a single and smooth yield surface. It would be a pertinent one which fulfills the mechanical requirements for elastoplastic constitutive equation and which is applicable to an arbitrary loading process. Based on this equation, a constitutive equation of metals with the isotropic-kinematic hardening is formulated.