Analysis of Stress/Strain Field and Damage Evolution around a Crack-tip in Particulate-Reinforced Composite

Abstract

A crack-tip field in particulate-reinforced composite which contains hard particles dispersed homogeneously in a ductile matrix has been analyzed taking account of damage evolution. In such a composite, debonding of particle-matrix interface is a significant damage, because the damaged particles have a weakening effect while the intact particles have a reinforcing effect. A new finite element method is developed based on Tohgo-Chou's constitutive relation which describes the elastic-plastic behavior and the damage behavior of particulate-reinforced composites. In this constitutive relation, it is assumed that the debonding damage is controlled by the stress of the particle and the statistical behavior of particle-matrix interfacial strength, the debonded (damaged) particles are regarded as voids, and a void volume fraction increases with deformation. Analyses of stress/strain field and damage evolution around a crack tip in particulate-reinforced composites are carried out by the FEM. With an increase in stress intensity, the debonding damage spreads out, and the damaged zone is constructed ahead of the crack tip. This debonding damage drastically influences the distributions of macroscopic and microscopic stress/strain fields around the crack tip.