Computational analysis of deformation and fracture in a composite material on the mesoscale level

Presented in this paper are the computational results on deformation and fracture in an aluminum-matrix composite. 2D numerical simulations were carried out using the finite-difference method. To describe the mechanical behavior of elasto-plastic matrix and brittle inclusions use was made of different models—elasto-plastic formulation with the strain hardening and a cracking model with a fracture criterion of Huber type, respectively. The fracture criterion takes into account a difference in critical values for different local stress–strain states: tension and compression. The initial structure of the mesovolume, elastic and strength material constants, as well as the strain hardening function were chosen from the experiments. It has been shown that the composite mesovolume exhibits complex mechanical behavior controlled by both shear band formation in the matrix and cracking of inclusions. When applied to simulation of deformation and fracture in a heterogeneous medium, the criterion proposed allows one to describe adequately direction of crack propagation under different types of loading (tension and compression). The computational results have been analyzed in details, taking into account analytical solution for inclusion problem.