Modeling matrix cracking of fiber-reinforced ceramic-matrix composites under oxidation environment at elevated temperature

Abstract

In this paper, the matrix cracking stress of fiber-reinforced ceramic-matrix composites (CMCs) has been investigated using the energy balance approach considering oxidation at elevated temperature. The shear-lag model cooperated with the interface oxidation model and interface debonding criteria has been adopted to analyze the micro-stress field in the composite. The relationships between matrix cracking stress, interface debonding and slipping, oxidation temperature and time have been established. The effects of fiber volume fraction, interface properties, oxidation temperature on the evolution of matrix cracking stress versus oxidation time have been analyzed. The matrix cracking stresses of C/SiC with strong and weak interface bonding after unstressed oxidation at 700°C in air have been predicted for different oxidation time. It was found that the strong interface bonding can be used for oxidation resistant of C/SiC at elevated temperature.