An incremental damage theory for micropolar composites taking account of progressive debonding and particle size effect

The paper presents an incremental damage model for determining the overall mechanical behaviors of particulate-reinforced micropolar composites. The particle size effect and progressive-debonding damage are fully accounted for within the present framework, which makes use of the micropolar Eshelby’s tensor for characterizing the size-dependent constraint of the matrix microstructure on the particles, a critical stress criterion for the interfacial debonding, and Qiu-Weng’s energy approach, together with Hu’s variation method for the equivalent stress of the matrix. Finally, the present model was applied for the predictions of the overall stress–strain relations of the composites that reinforced by either particles or voids, and are subjected to the uniaxial tension. It is shown that all the predictions are in good agreement with the experiments and finite element computations.