Elastic model for the sweeping of dipolar loops

The sweeping of small dipolar loops by gliding dislocations is thought to b e one of the mechanisms leading to dislocation pattern formation during cyc lic deformation. The individual sweeping event was calculated within the fr amework of isotropic linear elasticity for an infinite straight gliding seg ment and a rigid dipolar prismatic loop. With respect to previous estimates , the present one includes the finite size of the loop and the character of the gliding dislocation. The conditions for sweeping were quantitatively e stimated as a function of the geometrical factors and the local effective a nd friction forces. The sweeping mechanism is found to be effective for dis tances between the slip planes of the two defects smaller than 9 times the height of the dipolar loop.