Weight function for a crack in an orthotropic medium under normal impact loading

The paper deals with the investigation of an elastodynamic response of an infinite orthotropic medium containing a central crack under normal impact loading. Laplace and Fourier integral transforms are employed to reduce the dimensional wave propagation problem to the solution of a pair of dual integral equations in the Laplace transform plane. These integral equations are then reduced to integral differential equations which have been solved in the low frequency domain by method of iteration. To determine time dependence of the parameters, these equations are inverted to yield the dynamic stress intensity factor (SIF) for normal point force loading. These results have been used to obtain the SIF at the crack tip which corresponds to the weight function for the crack under normal loading. Analytical expressions of the weight function are used to derive SIF for polynomial loading. Numerical results of normalized SIF for a large normalized time variable and for different concentrated point force loading at an arbitrary location of the crack surface have been calculated for different orthotropic materials. In the present paper, a numerical Laplace inversion technique is used to recover the time dependence of the solution. Finally, the results obtained are displayed graphically.