Integral equation approach for 3D multiple-crack problems

In this paper, a traction integral equation containing no hypersingular integrals is presented to study the interaction of multiple cracks in an infinite elastic medium. 8-node quadratic quadrilateral elements are used to discretize general crack surfaces, and special crack tip elements are employed along surface boundaries to model the √r variation of displacements near the crack fronts. Thus, the method possesses the merits of the traction integral equation without hypersingular integrals and those of the special crack tip elements for modeling √r variation of displacements near the crack tips. The stress intensity factors at the crack front are evaluated using one point formulation and the results are compared with available solutions.