Generalized midpoint integration algorithms for J2 plasticity with linear hardening

We consider four schemes based on generalized midpoint rule and return map algorithm for the integration of the classical J2 plasticity model with linear hardening. The comparison, aiming to establish which is the preferable scheme among the four considered, is both theoretical and numerical. On one side, extending and completing the existing results in the literature, we investigate the four schemes from the theoretical viewpoint, addressing in particular the existence of solution, long-term behaviour, accuracy and stability. On the other hand, we develop an extensive set of numerical tests, based on pointwise stress-strain loading histories, iso-error maps and initial boundary-value problems