Abstract: The composites reinforced by particles with high volume fraction are widely used in engineering field. In this work, the elastoplastic micromechanical model is established for such composites, and the macroscopic elastoplastic mechanical properties under uniaxial tension and compression are systematically studied. In the aspect of effective modulus prediction, the Mori-Tanaka model and the interaction micromechanics model proposed by Ju et al. are employed to study the effective modulus of the particle reinforced composites with high volume fraction, and the limitations of the Mori-Tanaka model are addressed. For the particle reinforced composites with high volume fraction, the Hill's theorem and the field fluctuation method are employed to formulate the relationship between the macroscopic stress and the equivalent stress of the matrix. Within the theoretical framework, the Mori-Tanaka model and Ju's model are respectively used to study the macroscopic elastoplastic properties of such material with different particle volume fraction. The comparisons between the theoretical prediction with experimental data and finite element simulation results are made. The results show that, for the macro-elastoplastic properties of high volume fraction particle reinforced composites, the prediction results of the proposed model are more accurate than those of the traditional model, and such model may provide a theoretical reference for the prediction of the elastoplastic properties of such materials in the engineering field.

Key words: particle reinforced composites, high volume fraction, elastoplasticity, micromechanics