The finite element analysis of crack tolerance in composite ceramics

A finite element simulation is employed to provide a thorough investigation of fracture tolerance in ceramic materials containing lamellar inhomogeneities. The opening mode crack initiated in matrix, inhomogeneity and at interphase boundary is considered in terms of energy release rate accompanying the flaw growth to define the most feasible fracture configurations. The dependences of the crack energy release rate on sizes of crack and inhomogeneity, and elastic moduli of materials are shown and discussed. It is demonstrated that the energy release rate reaches its maximum value at certain ratios of inhomogeneity-to-matrix shear moduli and crack-to-inhomogeneity sizes.