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

Abstract

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.