Damage evolution and life prediction of different 2D woven ceramic-matrix composites at room and elevated temperatures based on hysteresis loops

In this paper, the damage evolution and life prediction of different 2D woven fiber-reinforced ceramic-matrix composites (CMCs), i.e., C/SiC, SiC/SiC, SiC/Si-N-C, Nextel 610™/Aluminosilicate, and Nextel 720™/Aluminosilicate, at room and elevated temperatures have been investigated. The evolution of fatigue hysteresis dissipated energy and interface shear stress versus cycle number curves have been analyzed. The fatigue life S-N curves and broken fibers fraction versus cycle number have been predicted. For non-oxide CMCs, i.e., C/SiC, SiC/SiC or SiC/Si-N-C, the fatigue limit stress greatly reduces at elevated temperature in air, i.e., 21% tensile strength of C/SiC at 550 °C in air, 25% tensile strength of SiC/SiC at 800 °C in air, and 25% tensile strength of SiC/Si-N-C at 1000 °C in air; however, for oxide-oxide CMCs, the fatigue limit stress is much higher than that of non-oxide CMCs, i.e., 60% tensile strength of Nextel 610™/Aluminosilicate and Nextel 720™/Aluminosilicate at 1000 °C and 1200 °C in air.