Interaction of a pair of coplanar central cracks in an orthotropic strip of finite width

Abstract

The interactive effects of a pair of coplanar central cracks in an orthotropic strip with finite width are investigated using the techniques of Fourier transforms and finite Hilbert transforms. The surfaces of the cracks are subjected to uniform pressures, while the edges of the strip are free from stresses. The solutions are largely written in terms of the sum and difference of the characteristic root so that the results can easily be seen as real-valued functions for both real and complex roots. Exact expressions for the stress-intensity factors at the inner and outer crack tips and for the crack shape are obtained as products of dimensional quantities and nondimensional functions in terms of material constants, strip width, and a varying distance between the cracks. The nondimensional functions are calculated numerically for various values of nondimensional parameters for three different materials that involve both real and complex characteristic roots. The interactive effects of the cracks on the stress-intensity factors and on the crack surface opening are described in terms of the distance between the cracks, the material anisotropy, and the strip width.