Uniaxial tensile behavior of cross-ply ceramic matrix composites

The uniaxial tensile stress-strain behavior of cross-ply ceramic matrix composites has been investigated using a micro-mechanical approach. The shear-lag model was adopted to obtain the micro stress field of the damaged composites. The fracture mechanics approach, critical matrix strain energy criterion, strain energy release rate criterion and Curtin’s statistical approaches were used to determine transverse crack space of 90° ply, matrix crack space of 0° ply, fiber/matrix interface debonded length and fiber failure volume fraction. By combining the shear-lag model with the failure criterion, the tensile stress-strain curve of each damage stage was modeled, and the exact model of predicting the toughness and strength of the composite was established. The uniaxial tensile stress-strain curve of cross-ply ceramic matrix composite at room temperature was compared with the present analysis. The stress-strain curve of each damage stage, the failure strength and failure strain agree well with the experimental data. The effects of fracture energy of 90° ply, fiber/matrix interface shear stress, interface debonded energy, and fiber Weibull modulus on the damage of the composite and the stress-strain curve were also investigated.