DYNAMIC PROPAGATION OF A FINITE CRACK

A transient analysis of a propagating finite crack of opening mode is considered. A two-dimensional singular integral equation is formulated for the rotation of the crack surface by the method of integral transform. The dynamic stress intensity factor is determined by use of the value of the strength of the square root singularity in the rotation at the crack tip after solving the integral equation numerically. The motion of the crack tips and the load on the crack face are not prescribed in the formulation of the problem. Therefore, the method of solution is applicable to nonuniform rates of propagation of a crack under an arbitrary time dependent load on the crack face. As example problems, the diffraction of a uniform dilatational wave by (1) a stationary crack, (2) a propagating crack with constant speed and (3) a suddenly stopping crack after propagating with constant speed is considered. The dynamic stress intensity is computed for a wide range of time in each problem. © 1979.