Crack tip stress and displacement fields are useful for studying the fractu
re behavior of cracks in both isotropic and anisotropic materials. Under ce
rtain boundary conditions, crack surfaces could overlap, a condition that c
ould be more prevalent for the anisotropic case as compared with isotropic
materials. Conditions can be derived for different loading conditions and m
aterial properties such that overlap of the crack faces would not occur. (C
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