Extended Subloading Surface Model for Elastoplastic Deformation

Abstract

Abstract The subloading surface model does not assume a yield surface enclosing a purely elastic domain, and instead it assumes a subloading surface which always passes through a current stress point even in the unloading state. Thus, it describes a continuous stress rate-strain rate relation and its loading criterion does not require the judgement whether a current stress lies on a yield surface or not. In this paper, a mathematically exact formulation of this model is presented so as to be capable of describing a continuous stress rate-strain rate relation, an anisotropic hardening/softening and a hysteresis effect consistently, formulating a reasonable translation rule of the center of similarity of the normal-yield and the subloading surfaces and a plastic strain rate equation based on the extended consistency condition and deriving the associated flow rule for materials without a purely elastic domain.