PLASTIC-POROUS MATERIAL AS A DAMAGED CONTINUUM. APPLICATION TO MICRO-VOIDS NUCLEATION.

摘要

Plastic porous materials undergo void nucleation and growth under applied stresses. Generally, extended Gurson schemes are used in order to solve various problems: as in the original work of Gurson [1], a yield surface is employed that was obtained as a necessary condition from the matrix yield criterion. So "void growth models" are proposed in literature, as in the recent works [2,3]. In some recent papers [4,5], these models were recognised incomplete to consider void growth problems as relevant to the Continuum Damage Mechanics: it was shown the necessity to make use simultaneously of the matrix yield condition together with the Gurson condition, leading to non smooth yield surfaces. In this paper such schemes are defined and an analysis of a nucleation problem is proposed as an example.