Recovering convexity in non-associated plasticity

作者：Francfort Gilles A^*

来源：Comptes Rendus Mecanique, 2018, 346(3): 198-205.

DOI：10.1016/j.crme.2017.12.005

• Elasto-plasticity
• Non-associated flow rules
• Quasi-static evolution
• Convex analysis

We quickly review two main non-associated plasticity models, the Armstrong-Frederick model of nonlinear kinematic hardening and the Drucker-Prager cap model. Non-associativity is commonly thought to preclude any kind of variational formulation, be it in a Hencky-type (static) setting, or when considering a quasi-static evolution because non-associativity destroys convexity. We demonstrate that such an opinion is misguided: associativity (and convexity) can be restored at the expense of the introduction of state variable-dependent dissipation potentials.

• 出版日期2018-3