Modeling on temperature-dependent first matrix cracking stress for fiber reinforced ceramics considering fiber debonding and residual thermal stress

Abstract

The combined effects of temperature, fiber debonding and residual thermal stress on the first matrix cracking stress for fiber reinforced ceramic matrix composites were investigated. We analyzed the temperature-dependent stress fields in the fiber and matrix by using the modified shear-lag model, and developed a temperature-dependent interface debonding criterion. Then, based on the energy balance approach, a temperature-dependent first matrix cracking stress model considering the effects of fiber debonding and residual thermal stress was established. The model predictions were compared with the available experimental results, which shows good agreement between the theoretical predictions and experimental results. Moreover, the quantitative effects of fiber volume fraction, interface debonded energy and interface frictional shear stress on the first matrix cracking stress and fiber debonding length were analyzed in detail at different temperatures. This work not only helps understand the matrix cracking behavior of fiber reinforced ceramic matrix composites with general interfacial properties at high temperatures, but also provides a guidance for the material design.