Micromechanics Proportional Limit Stress of Ceramic-Matrix Composites Under Monotonic Tensile Loading at Elevated Temperatures

Under tensile loading at elevated temperature, the proportional limit stress (PLS) of SiC/SiC ceramic-matrix composites (CMCs) was investigated using the micromechanical approach. The energy balance approach was used to predict the PLS of SiC/SiC composites considering environment temperatures. Relationships between the PLS, composite damage state, and environment temperatures were established. Experimental PLS and interface debonding length of 2D SiC/SiC composites at elevated temperatures were predicted. Effects of the fiber volume, interface properties, and matrix properties on the PLS and composite damage state of SiC/SiC composite at elevated temperatures were analyzed.