Abstract: Generalized selfconsistent finite element iterative averaging method was united with the Gurson model for the parametric investigation of the damage mechanisms and their relations with the macroscopic tensile properties of the SiC reinforced Al₅₄₅₆. The mesoscopic damage mechanisms studied here contained two types: interphase debonding between the reinforcement and matrix and the nucleation, growth, and coalescence of the voids in the matrix. As shown by the results, the interphase debonding increases the composite ductility, but results in the strengthening effects of the brittle reinforcements decreasing unfavorably.