Abstract:A yield criterion of the particle-reinforced composites is developed based on the asymptotic homogenization method. According to the yield criterion, the initial yield stresses are predicted in analytical forms. Because the elastic modulus of the particle reinforcement is much higher than that of the elastic-plastic matrix, the difference of the elastic modulus results in an assembly stiffness in the reinforcement and the matrix. The assembly stiffness can be obtained by solving a local problem. It can be seen from the expressions of the yield stress that the increase of yield stress of the composites is determined by the ratio of the average assembly stiffness and shear modulus of the reinforcement and matrix. Two numerical examples are given. A rhombic dodecahedron cell is used to solve the local problem. The advantages of using rhombic dodecahedron as a cell are that the volume ratio of reinforcement can be as high as 74%.