The velocity of a wave along a dislocation

Abstract The behaviour of a small-amplitude infinite standing or travelling sine wave on a dislocation is examined. For a certain range of frequencies and wavelengths no elastic energy is radiated, but in general a suitable applied stress is required to maintain the motion. When, however, a certain relation between frequency and wavelength is satisfied no applied forces are necessary and the motion is self-maintaining. This relation may be expressed analytically in the limit of very long wavelengths, but in general it must be evaluated numerically. Curves are given for edge, screw and 60° dislocations in materials with various Poisson ratios. In the course of the calculation a value for the line tension of a sinusoidally deformed stationary dislocation is also obtained.