MULTIPLE CRACKS IN TRANSFORMATION-TOUGHENED CERAMICS

The problem of a collinear array of cracks in a transformation toughened ceramic under monotonically increasing load is analyzed by the theory of complex potentials and dislocation formalism. The analysis is applicable to both a homogeneous material containing multiple cracks and a brittle matrix ceramic reinforced by distributed transformable particulates. The detrimental effect of transformation at the onset of crack growth is generally found to be amplified by crack tip interactions. For the particulate reinforced ceramic the maximum relative strengthening is achieved for moderate volume fractions of large particles.