Micromechanics Lifetime of Ceramic-Matrix Composites Under Cyclic Fatigue Loading at Elevated Temperatures

In this chapter, the lifetime of C/SiC and SiC/SiC ceramic-matrix composites (CMCs) under cyclic fatigue loading at 1300 °C in vacuum, inert, air, and steam atmospheres was investigated. The damage development was analyzed using different damage parameters. The Global Load Sharing (GLS) criterion was adopted to determine the stress distribution between intact and broken fibers. The fibers failure probability in different damage regions was determined considering the damage mechanisms of interface wear, interface oxidation, and fiber oxidation. The fatigue lifetime and fatigue limit stress of C/SiC and SiC/SiC composites at 1300 °C under different testing conditions were predicted.