Evaluation of crack development in ribbed panels

The problem of elastic equilibrium for a finite anisotropic ribbed panel weakened by a rectilinear crack is considered. Within the framework of a hypothesis of continuous contact of a rib and a plate along a line special presentations are given for obtaining and solving a set of singular integral equations. Absence of an unknown function in the notch contour makes it possible to reduce the order of the set of singular integral equations by one and to propose an effective algorithm for numerical solution of the problem. The effect of material anisotropy, plate edges, and reinforcement stiffness on the stress intensity factor at the crack tip are studied. Calculated results are compared with experimental data for the case of an isotropic plate.Translated from Problemy Prochnosti, No. 3, pp. 63–68, March, 1991.