A cyclic-dependent vibration damping model of fiber-reinforced ceramic-matrix composites

Abstract

Under cyclic fatigue loading, cyclic-dependent damage mechanisms affect the vibration damping of fiber-reinforced ceramic-matrix composites (CMCs). In this paper, a cyclic-dependent vibration damping model of fiber-reinforced CMCs is developed. Combining cyclic-dependent damage mechanisms, damage models and dissipated energy model, relationships between composite vibration damping, cyclic-dependent damage mechanisms, vibration stress and applied cycle number are established. Effects of material properties and damage state on composite vibration damping are analyzed for different applied cycle number and vibration stress. Experimental composite vibration damping of 2D and 3D C/SiC composites without/with coating is predicted for different vibration frequencies and applied cycle number. With increasing applied cycle number, cyclic-dependent composite vibration damping increases due to the increase ratio of interface debonding and slip. When fiber volume and matrix cracking spacing increase, cyclic-dependent composite vibration damping decreases due to the decrease ratio of interface debonding and slip.