The bowing of a dislocation segment

The bowing under stress of a segment of an otherwise straight dislocation line has been determined for an isotropic solid. A digital computer is used to relax the dislocation to its equilibrium shape, using a variant of the Brown self-stress method. The critical stress required to make the dislocation become unstable has been determined for a wide range of segment lengths, and is in fair agreement with the predictions of the line tension model. The results are relevant to a Frank-Read source, since the elevation of the side-arms is shown to have a relatively minor effect on the critical bowing. The bowing of a screw dislocation between several attractive forest screw dislocations has also been considered.