Crack propagation in monolithic ceramics under mixed mode loading
Finite element calculations are presented for a semi-infinite crack in a brittle solid undergoing microcracking normal to the maximum tensile direction. Microcracks are presumed stable and a saturation stage is postulated wherein the effective elastic moduli attain steady state values. Mode I, mode II and mixed mode loading conditions are investigated. In these two latter cases, the method of analysis employed allows for cracks to grow out of their initial planes. The mixed mode loading case investigated corresponds to taking equal values of the remote mode I and II stress intensity factors. Contrary to what is observed in the mode I case, no appreciable R-curve behavior is found under mode II or mixed mode conditions.
© Kluwer Academic Publishers 1990. Received 20 October 1988; accepted in revised form 30 March 1989. The support of the Office of Naval Research through grant N00014-85-K-0720 is gratefully acknowledged.