Implicit J2-bounding surface plasticity using Pragerʹs translation rule

A bounding surface J2-plasticity model that uses Prager’s translation rule is presented. The model preserves Masing’s rules and is developed from the same ideas as classical in nitesimal J2-plasticity, resulting in the same formulation with the exception of the algorithm for the computation of the hardening function. Instead of utilizing a loading surface as in a previous formulation, hardening surfaces are introduced; the formulation is similar to that of multilayer plasticity using Prager’s rule, presented in previous work. An implicit algorithm based on the radial return concept is used, and the consistent elastoplastic tangent is also developed in closed form. Examples illustrating anisotropic behaviour are presented and compared to that predicted by a multilayer J2-plasticity model. The model is also applied to a soil dynamics problem to show the robustness of the algorithm and its applicability to complex loading.