Analysis of the elastoplastic behavior of porous microstructures under volumetric strains through a computational homogenization procedure

Resumo

The rupture processes in ductile materials such as metals and alloys occur by concentration of plas-
tic strains around impurities in the microstructure. Therefore, the formulation of realistic constitutive models for

these materials requires consideration of the effects of this heterogeneity on the distribution of stresses and strains
at the microscale. These impurities are generally considered as voids due to the tendency of detaching from the
surrounding matrix during the deformation process towards rupture. Moreover, different simplifications of the
morphology of both void and matrix portion around it may imply different constitutive responses for identical load
situations. Constitutive responses of porous materials can be constructed through computational homogenization
procedure considering the behavior of representative volume elements (RVE). In this context, the present paper
examines three different geometric configurations of ductile porous media RVE’s subjected to volumetric strains.

The matrix of each RVE is considered to be perfectly elastoplastic undergoing small strains regimes. The homog-
enized constitutive responses of the RVEs are obtained by averaging the stress and strain fields computed by Finite

Element Method (FEM) analyses. The results hereby presented emphasize the determinant influence of the studied
morphologies on the constitutive responses as the load level approaches the rupture regime.