Computation of stress intensity factors for a 2-D body from displacements at an arbitrary location

An approach to stress intensity factor computation is presented which allows accurate estimation using a simple finite element program and a coarse mesh of elements. The stress intensity factor is obtained from what we term the Crack-Displacement (C-D) Factor. This involves the rate of change of displacements with crack length at the same location remote from the crack due to two loading conditions. One loading condition is merely that applied to the cracked body. The other loading condition is a virtual line force applied at the location at which the displacement rates are computed. The accuracy of the procedure is demonstrated for uniform tensile stresses applied to a center-cracked panel and an edge-cracked strip.