叠层穿刺CF/Al复合材料准静态拉伸力学行为与失效机制

A novel aluminum matrix composite reinforced with laminated puncture carbon fiber fabric (CF/Al composites) was prepared. The progressive damage and mechanical behavior of the composite subjected to quasi-static tensile loading were investigated by using test and micromechanical simulation method. The test results show that the tensile modulus, ultimate strength and fracture strain are 129.61 GPa, 630.14 MPa, and 0.75%, respectively, and the calculation errors of the above property parameters are -9.41%, 7.57% and 1.33%, respectively. The macroscopic stress-strain curve from the micromechanical simulation agrees well with the test result. At the initial tensile stage, local damages were found in the matrix alloy located between the warp and weft yarns. With the increase of tensile strain, these damage zones accumulated gradually and led to the transverse cracking of weft yarns and piercing yarns in sequence. Thereafter, the warp yarns and matrix alloy failed successively, leading to dramatical dropping of the macroscopic stress-strain curve at the final tensile stage. The tensile fracture morphology was characterized by coexistence of fracture of warp yarns and transverse cracking of weft and piercing yarns. The axial fracture of warp yarns, which was induced by fiber pulling-out and matrix tearing, was the dominant failure mechanism of the composites under the condition of warp-directional tensile loading.