Dynamic mode II stress intensity factors of an infinite cracked medium subjected to transient concentrated forces

Abstract

In this article the determination of dynamic mode II stress intensity factors of a crack embedded in an infinite medium subjected to transient concentrated line forces is investigated. The concentrated line forces act at an arbitrary distance away from the crack, including the special case when the forces act precisely on the crack surfaces. Laplace and Fourier transforms are used to reduce the mixed boundary value problem to a standard Fredholm integral equation of the second kind in Laplace transform domain, which is solved numerically. Via the numerical inversion of Laplace transform, the dynamic mode II stress intensity factors at the crack tips are obtained and presented in graphical form for various geometry parameters. It is found that the point of application of the concentrated forces, which induce the maximum value of the dynamic mode II stress intensity factors, is precisely on the crack surface for horizontal concentrated forces, whereas for vertical forces, it is at some distance away from the crack.