[hal-01068888] A family of bi-potentials describing the non-associated flow rule of pressure-dependent plastic models

In this paper, we discuss in detail the derivation of the bi-potential function used to express the flow rule of pressure-dependent non-associated plastic models. In particular, we show that an infinity of equivalent expressions of the bi-potential can be derived for pressure-dependent models. The method consists in applying a transformation to the plastic strain rate or the stress or both to recover the normality rule. Then, the Fenchel inequality is used to derive the bi-potential function. The construction method itself indicates clearly that a class with infinite equivalent expressions of the bi-potential can be derived.



from HAL : Dernières publications http://ift.tt/1pxeyHF