Stress and failure analysis of brittle matrix composites. Part II: Failure analysis

摘要

A linear elastic fracture mechanics analysis of acylindrical element of matrix with a single fiber and two matrixannular cracks perpendicular to the fiber direction underlongitudinal tensile load was undertaken. The order of singularityand the angular dependence of the stress field in theneighborhood of the crack periphery were determined by usingthe stress function approach proposed by Zak and Williams. Thestress intensity factor was evaluated by combining the results ofthe local stress solution with a finite element analysis. The caseof fiber debonding origination from the periphery of the annularcracks was also studied. For that problem both opening-mode andsliding-mode stress intensity factors and the strain energy releaserate were determined. These results help to understand thevarious failure mechanisms including matrix cracking, debondingalong interfaces and kinking of interface cracks into fibers inbrittle matrix composites.