THE MIXED-MODE CRACK PROBLEM IN A NONHOMOGENEOUS ELASTIC MEDIUM

A nonhomogeneous elastic medium containing a crack arbitrarily oriented with respect to the direction of property gradient is considered. The problem is solved under plane strain or generalized plane stress conditions. This is a highly simplified version of a class of physical problems that may arise in fracture mechanics studies of ceramic coatings, metal/ceramic composites and interfacial zones with continuously varying volume fractions or graded properties. The main results of the paper are the calculated mode I and II stress intensity factors. Among the questions studied are the effects of the material nonhomogeneity constant, the crack orientation, the loading conditions and the Poisson's ratio on the stress intensity factors. The stress state near the crack tip and the crack opening displacement are also briefly discussed.