Fatigue hysteresis behavior of cross-ply C/SiC ceramic matrix composites at room and elevated temperatures

The tensile fatigue hysteresis behavior of cross-ply C/SiC composites at room and elevated temperatures in air atmosphere has been investigated in present analysis. The hysteresis modulus and hysteresis loss energy corresponding to different cycles have been analyzed. Based on damage mechanisms of fiber sliding relative to matrix in fiber/matrix interface debonded region upon unloading and subsequent reloading, the hysteresis loops models considering different matrix cracking modes have been developed. The hysteresis loss energy for strain energy lost per volume during corresponding cycle is formulated in terms of fiber/matrix interface shear stress. By comparing experimental hysteresis loss energy with computational values, fiber/matrix interface shear stress of cross-ply C/SiC composites at room and elevated temperatures has been estimated.