Mixed mode crack-tip fields in monolithic ceramics
Asymptotic and full field finite element solutions are given for a semi-infinite planar crack in a monolithic ceramic subjected to remote mixed mode loading. The material is assumed to undergo damage in the form of elastic degradation as a result of stable microcracking. Microcracks are assumed to be preferentially oriented normal to the direction of maximum tension. An outcome of the analysis is that microcracks shield the crack tip less effectively under mode II than under mode I conditions. Other issues addressed concern the relation between the mixities of the applied loads and the near-tip fields, the path-independence of the J integral, the validity of deformation theories of damage under proportional loading, and the conditions for dominance of the singular near-tip fields.
© 1990 Elsevier. Received 28 July 1988, Revised 21 December 1988. The support of the Office of Naval Research through grant N00014-85-K-0720 is gratefully acknowledged.