Z-pin增强C/SiC力学行为研究

ensile behavior of ceramic matrix composite (CMC) with Z-pins reinforcement was investigated. A preform consisting of plain-weave fabric and Z-pins through thickness reinforcements was infiltrated by chemical vapor infiltration (CVI) technique. The uniaxial unloading and reloading tensile test was used to investigate the tensile damage behavior. The fracture mechanism of the composite was studied by scanning electron microscopy (SEM). The result shows that the tensile strength of plain-weave ceramic matrix composite is reduced lesser because of damage, fracture and flexural deformation of the in plane fiber during pins insertion. The stress-strain curve of the laminate is nonlinear, and the damage undergoes slowly propagating, rapidly propagating and reaches saturation. The relationship between residual strain and unloading stress is quadratic function, and the relationship between unloading modulus and unloading stress is Boltzmann. The relationship between strain and stress of the laminate of plain-weave ceramic matrix composite is obtained.