Crack extension and arrest within the particle subjected to tensile thermoelastic stresses in brittle matrix composites

Abstract

A stress relaxation mechanism which entails circumferential cracking around a spherical particle is presented. In a dispersion-strengthened system, composed of spherical particles of different elastic and fracture properties and a matrix of lower thermal expansion, the location and extent of crack propagation is determined by the relative magnitude of elastic and fracture properties of the matrix and the particulate phase. A simple energy balance criteria is adopted to describe the extent of post-initiation crack propagation and to show the relationship between the initial flaw size and the arrested crack length. The major implications of the analysis are discussed in the light of the reported experimental data.