Growth rate of crack opening displacement in ceramic-matrix composites: Theory and analytical prediction

In this paper, the growth rate of crack opening displacement (COD) in ceramic-matrix composites (CMCs) was investigated using the micromechanical approach. Two damage states of interface partial and complete debonding were considered in determining the CODs and growth rate of CODs considering synergistic effects of fiber bridging and broken. Experimental CODs and growth rate of CODs in SiC/SiC minicomposites with low and high fiber contents were predicted using the developed micromechanical model. Effects of composite constitutive properties, e.g., fiber volume fraction, interface properties and fibers properties, and damage state (i.e., the matrix crack spacing) on the growth rate of CODs and internal damages (e.g., interface debonding ratio and fibers failure probability) were discussed. Relationships between the CODs, growth rate of CODs, and interface debonding ratio were established.