An enhanced concept of rheological models to represent nonlinear thermoviscoplasticity and its energy storage behavior

An enhanced rheological network is presented for the material modeling of thermoviscoplasticity. By introducing new basic elements, nonlinear isotropic and kinematic hardening may be depicted as well as an improved description of energy storage and dissipation during plastic deformations. Satisfying the thermomechanical consistency, the yield function and the flow rule are directly deduced from the stress equilibrium and the kinematics of the rheological network by means of simple algebraic calculations. Novel approaches are proposed to account for a process-dependent energy storage also for the case of ideal plasticity. The resulting energy storage behavior is investigated and validated by means of the simulation of tension test data.