Study of Microstructural Effect in Particulate Composites

Abstract

The effects of random and non-uniform particle distribution on the damage initiation and growth leading to a crack were investigated for particulate composites using a multi-scale technique. Damage was described at the constituent material level (i.e. micro-level) and the results compared well qualitatively and quantitatively with experimental observation. Non-uniform, random particle distribution yielded sporadic crack initiation and growth within a uniform tensile specimen. No local crack propagated beyond a certain size. Breakage of the specimens was not caused by the continuous growth of a single critical crack. Instead, coalescence of neighboring sporadic short cracks resulted in breakage of the specimens. Computer simulation indicated that random particle distribution affected the strength of the composite significantly, but as expected, not its effective stiffness.