A Numerical Analysis of Crack Growth in Microcracking Ceramic and Ceramic Composites

Abstract

ABSTRACTA set of numerical analyses of crack growth was performed to elucidate the influence of microcracking on the fracture behavior of microcracking ceramic and ceramic composites. The random nucleation, orientation and size effects of discrete nucleating microcracks and resulting interactions are fully accounted for in a hybrid finite element model. The results obtained from the finite element analysis are compared with the continuum description of the microcracking. Although continuum description can provide a reasonable estimation of shielding, it fails to resolve the details of the micromechanism of toughening resulting from microcracking, since not every shielding event during the course of crack extension corresponds to an increase in the Rcurve. Moreover, as seen in the composite cases, the local events leading to toughening behavior may not be associated with the microcracking, even in the presence of large population of microcracks.