Damage analysis of aluminum matrix composite considering non-uniform distribution of SiC particles

In this study, based on the fracture surface observations using an SEM (scanning electron microscope), a numerical unit model and 3-dimensional non-uniform model for FEM (finite element method) analysis are proposed by using Gurson's model as a constitutive equation. The effect of the non-uniform distribution of the SiC particle volume fraction and aspect ratio in the matrix are considered for the evaluation of the stress-strain relationship and the damage. The results show that the dimple fracture process of matrix aluminum alloy is well simulated, after a large amount of plastic deformation. The non-uniformity of the SiC particle volume fraction, aspect ratio and its locations have a strong effect on the local and global damage behavior and stress-strain relationships. It is shown that the fracture strain increases largely when the aspect ratio of SiC particles is 1.0 and it is distributed uniformly in the matrix. The numerical model is improved by considering the non-uniform effect on the tensile stress, fracture strain and local and global fracture. (C) 1998 Acta Metallurgica Inc.