On 3D cracks intersecting a free surface in laminated composites

摘要

In two- and three-dimensional linear elasticity, thesingularities together with matched asymptotic expansions allowto extend the brittle fracture mechanics. Although there existsome differences between 2D and 3D approaches, the usual cracktip singularity exponent 1/2 remains in both cases the hinge valuebetween strong and weak singularities. In 3D, 0 was expected tobe also a hinge, but it seems difficult to exhibit solutions with anegative exponent. One aim of this paper is to investigatenumerically such specific cases and to derive some asymptoticsof the classical stress intensity factors. The second part isdedicated to prove that, in case of a small linear ligament,negative exponents cannot exist.