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. Lap lace and Fourier transforms are employed to solve the equations of motion l eading to a Fredholm integral equation on the Laplace transform domain. The dynamic stress intensity factor history can be computed by numerical Lapla ce transform inversion of the solution of the Fredholm equation. Numerical values of the dynamic stress intensity factor history for some example mate rials are obtained. It is seen that the mode I stress intensity factor hist ory 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 up on the material constants. The solutions presented here can be used as a Gr een's function to solve dynamic problems involving finite cracks. (C) 2000 Elsevier Science Ltd. All rights reserved.