Plastic collapse in presence of non-linear kinematic hardening by the bipotential and the sequential limit analysis approaches

The limit analysis approach as a direct method limit loads assessment of plastic deformable bodies is followed up to deal with plastic collapse of non-linear kinematic strain hardening materials. For this goal, the kinematic and static approaches of modern limit analysis are adopted. The non-linear kinematic hardening law is a non-associative plastic flow rule, but, it can be described by the bipotential concept. Based on this, an extension of the limit analysis approach is proposed. Limit loads, back stresses and other variables are assessed at each step by the sequential limit analysis method. Large plastic deformation could be taken into consideration by updating geometry after each sequence.