Effect of microstructure of particle reinforced composites on the damage evolution: probabilistic and numerical analysis

The effect of particle clustering on the effective response and damage evolution in particle reinforced Al/SiC composites is studied numerically and analytically. A probability of material failure is determined on the basis of the model of a composite as an array of subdomains, and with the use of the probabilistic analysis of failure of matrix ligaments between particles. It was found that the clustered particle arrangement leads to the three times higher probability of specimen failure than the random uniform particle arrangement. Mesomechanical finite element simulations of damage evolution in the composite with clustered and uniform particle arrangements, and different amounts, sizes and volume contents of SiC particles have been carried out. Tensile stress-strain curves and the fraction of failed particles plotted versus the applied far-field strain curves were determined numerically for all the microstructures. It was shown that the failure stress of composites increases with increasing the average nearest-neighbor distance between the particles in the composite, and with decreasing the degree of clustering of particles. (C) 2004 Elsevier Ltd. All rights reserved.