Mixed mode dynamic stress intensity factor due to applied point loads

The elastodynamic response of an infinite orthotropic material with finite crack under normal and tangential concentrated loads is examined. Solution for the stress intensity factor history around the crack tips is found. Laplace and Fourier transforms are employed to solve the equations of motion leading to a Fredholm integral equation on the Laplace transform domain. The dynamic stress intensity factor history can be computed by numerical Laplace transform inversion of the solution of the Fredholm equation. Numerical values of the dynamic stress intensity factor history for some example materials are obtained. It is seen that the mode I stress intensity factor history is insensitive to the material parameters. For mode II due to the shear loads, the results differ from mode I in that there is heavy dependence upon the material constants. The solutions presented here can be used as a Greenʹs function to solve dynamic problems involving finite cracks.