Influence of the Shape of Curvilinear Cracks on the Dynamic Stress Intensity Factors

We study the influence of the shapes of smooth curvilinear cracks in infinite two-dimensional elastic domains on the time dependences of the stress intensity factors for various kinds of dynamic loads on the crack faces. By using a modified finite-difference method with respect to time, we reduce the dynamic problem to the solution of a system of singular integrodifferential equations for the jumps of displacements in passing through the crack contour at each analyzed time. The numerical solutions of the integral equations are obtained by the method of mechanical quadratures. We also analyze the time dependences of the dynamic stress intensity factors at the tips of curvilinear cracks located along the arc of a circle, of a parabola, or of a semiellipse for different impact and impulsive loads applied to the crack faces.