Generalized plastic flow rule

An elastoplastic constitutive equation capable of describing the tangential-plastic strain rate induced by the component of stress rate tangential to the subloading surface, called the tangential-plastic stress rate, is proposed based on the subloading surface model [J. Appl. Mech. (ASME) 47 (1980) 266]. Here, the novel tangential-yield surface and the novel tangential-loading criterion are incorporated for the tangential-plastic strain rate. The equation is capable of describing the deformation behavior with the smooth elastic–plastic transition. Based on the equation, a constitutive equation for metals is formulated, its mechanical features are examined and some basic responses are compared with test data.