Dynamic stress intensity factors around four rectangular cracks in an infinite elastic medium under impact load

The 3-D dynamic problem is presented for an infinite elastic medium weakened by four plane rectangular cracks of equal size. The surfaces of the cracks are loaded by a uniform pressure with Heaviside-function time dependence. Fourier-Laplace transform technique is utilized to reduce the problem to a solution of two simultaneous integral equations which can be solved by using the series expansion method. The Laplace transformed stress intensity factors are defined and are inverted numerically in the physical space.