三向正交纤维增强铝基复合材料经向拉伸渐进损伤及其断裂力学行为

A novel 3D orthogonal weaving carbon fibre reinforced Al-matrix composite was prepared by vacuum-pressure infiltration method. A finite element based micromechanical model by considering the interfacial action was developed according to the characteristics of cross-section morphology and weaving structure of yarns in the composite, and then the progressive damage and fracture behavior of the composites subjected to longitudinal tensile loading were assessed via experiment and numerical simulation. The results shown that the acquired tensile modulus, ultimate strength and fracture strain is 120.7 GPa, 771.75 MPa and 0.83%, respectively. The computationally predicted stress-strain curve agrees well with the experimental ones, and the calculation error of the above properties is -3.21%, 1.75% and -9.63%, respectively. At the initial tensile stage local interface failure was observed between the matrix alloy and Z directional yarns. With the increase of tensile strain, the matrix damage zone in the interspace of yarns accumulate gradually and lead to the transverse cracking of Z directional yarns and weft yarns successively. At the final tensile stage, the warp yarns and matrix alloy failed concurrently, and hence the composite lost its bearing capacity. Warp yarns fracture and transverse cracking of weft and Z directional yarns were observed on the tensile fracture morphology. The axial fracture of warp yarns, which play predominant role in load bearing, is flat and with limited fiber pull-out morphology. As a result, the composites exhibit quasi-brittle fracture behavior during the longitudinal tensile process.