Virtual Homogenization Tests on Porous Materials Using 3D RVEs

The mechanical strength of porous material is investigated using virtual tests by a computational homogenization method based on three-dimensional representative volume elements (RVE). The RVE consists of an elastic-perfectly plastic metal matrix, that obeys the von Mises criterion, having randomly distributed non-overlapping spherical voids. By using mixed boundary conditions and varying certain loading parameters, it is possible to obtain different macroscopic stress triaxialities. The macroscopic stress tensor is considered as the mean of its microscopic counterpart, taken for a stabilized RVE response in an asymptotic state. An in-house Abaqus post-processing tool developed in Python was used to examine the asymptotic behavior of porous microstructures. The analyzes are performed with different void volumes, multiple and single pores, and different boundary conditions. The Gurson and Gurson-Tvergaard-Needleman (GTN) models were compared with the results of the computational homogenization. The best GTN model that satisfies the homogenized numerical results is achieved among yield criterion parameters from various references. An examination of the shear macroscopic stresses nullity is also performed, demonstrating that it can produce significant values in specific scenarios.