Damage development and lifetime prediction of fiber-reinforced ceramic-matrix composites subjected to dwell-fatigue loading at elevated temperatures in oxidizing atmosphere

Abstract

In this paper, the damage development and lifetime prediction of fiber-reinforced ceramic-matrix composites subjected to the dwell-fatigue loading at elevated temperatures in oxidizing atmosphere have been investigated using the micromechanics approach. Considering the damage mechanisms of matrix multicracking, fiber/matrix interface debonding, interface wear and interface oxidation and fibers fracture, the damage evolution of the fatigue hysteresis dissipated energy, fatigue hysteresis modulus, fatigue peak strain and broken fibers fraction have been analyzed. The relationships between the fatigue hysteresis-based damage parameters and the internal damage development of matrix multicracking, fiber/matrix interface debonding and sliding and fibers fracture have been established. The experimental dwell-fatigue damage development and fatigue lifetime curves of cross-ply Nicalon·SiC/MAS and 2D Sylramic·SiC/SiC composites subjected to the dwell-fatigue loading at elevated temperatures in air and in steam conditions have been predicted.