Abstract:The unidirectional carbon fiber reinforced aluminum matrix composites (CF/Al composites) were prepared by vacuum assisted pressure infiltration method. The damage evolution and fracture mechanical behaviors of the composites under transverse compression condition were investigated by means of micromechanical numerical simulation and experimental methods. The effects of interfacial bonding properties and fiber volume fraction on the transverse compression behavior of the composites were analyzed. The results show that the micromechanical finite element model based on a diagonal square RVE can well predict the mechanical behavior of the composite under transverse compression. At the initial deformation stage, the interfacial damage and failure initiate at first, and then induce the local damage of the matrix alloy near the interface. With the increase of strain, the matrix damage accumulates gradually and leads to the local fiber failure. The microscopic fracture morphology of the composite presents the coexistence of interfacial debonding and fiber fracture. The transverse compressive elastic modulus and ultimate strength increase with the increase of interfacial strength, while the influence of interfacial stiffness is unobvious. Under the same interfacial property conditions, the ultimate compressive strength and elastic modulus of the composites decrease with the fiber volume fraction increasing.

Key words: CF/Al composites; transverse compression; micromechanics; damage evolution; mechanical property