2019 Volume 127 Issue 5 Pages 279-287
This paper reports on an investigation of time-dependent proportional limit stress of carbon fiber-reinforced silicon carbide ceramic-matrix composites (C/SiC CMCs). The temperature-dependent material parameters are considered to determine the proportional limit stress. The effects of the fiber volume fraction, interface properties and matrix fracture energy on the time-dependent proportional limit stress and interface debonding of C/SiC composite are discussed. The temperature-dependent proportional limit stress increases with the fiber volume fraction, interface shear stress, interface debonded energy and matrix fracture energy. The fiber/matrix interface debonded length increases as the oxidation time increases, leading to a decrease in the proportional limit stress. The experimental time-dependent proportional limit stresses of C/SiC composites corresponding to different oxidation times are predicted.