Synergistic effects of fiber debonding and fracture on matrix cracking in fiber-reinforced ceramic-matrix composites

In this paper, the synergistic effects of fiber debonding and fracture on matrix cracking stress of fiber-reinforced ceramic-matrix composites (CMCs) have been investigated using the energy balance approach. The shear-lag model cooperated with fiber/matrix interface debonding criterion and fiber fracture model has been adopted to analyze stress distribution in CMCs. The relationships between matrix cracking stress, interface debonding and slipping, and fiber fracture have been established. The effects of fiber volume fraction, interface shear stress, interface debonded energy, fiber Weibull modulus, and fiber strength on matrix cracking stress, interface debonded length and fiber broken fraction have been analyzed. The experimental matrix cracking stress of three different CMCs, i.e., SiC/borosilicate, SiC/LAS, and C/borosilicate, with different fiber volume fraction have been predicted.