This paper deals with a micromechanics model of particle-reinforced composites which can describe the debonding damage of particles from matrix, matrix plasticity and particle size effect on deformation and damage. Tohgo-Chou-Weng's incremental damage theory of particle-reinforced composites based on the Eshelby's equivalent inclusion method and Mori-Tanaka's mean field concept has been extended to consider the particle size effect by using Nan-Clarke's simple method. Numerical analyses are carried out on a SiC particle reinforced aluminum alloy composite (SiC/A356-T4) containing particles with size distribution under uniaxial tension. We compared our analytical results with the Lloyd's experimental results, and it is found that the experimental stress-strain relation of the SiC/A356-T4 can be described by the present model taking account of the particle size effect, particle size distribution and debonding damage.
