Various constitutive models for describing the inelastic stretching due to the stress rate component tangential to the yield or loading surface, i.e. the non-coaxiality of stress and inelastic stretching have been proposed in the past. However a pertinent model applicable to a general loading process for materials with an arbitrary yield surface has not been proposed up to the present. In this article, the inelastic constitutive equation extended so as to describe the non-coaxiality is formulated generalizing the Rudnicki and Rice`s [1] J2-deformation theory in rate form and incorporating it into the subloading surface model with a smooth elastic-plastic transition.
