SOLITON-LIKE BEHAVIOR OF A MOVING DISLOCATION GROUP

A new interpretation is presented of the results of numerical calculations of the dynamical behaviour of a dislocation group moving either freely or in dynamic pile-up formation. Both ‘relativistic’ and internal-stress softening effects are additionally taken into account. It is shown that the behaviour of a dislocation group can be considered in two representations, namely the propagation of dislocation density and shear-stress distributions, both strongly reminiscent of solitary-wave-like processes. Moreover, by considering the dynamic pile-up as the formation of a high-amplitude shear-stress impulse (called by us the ‘plaston’), it is suggested that plaston formation is a result of the interaction of a soliton-like process with an obstacle. This suggestion is discussed briefly in the context of experimental data on shear band propagation in polycrystalline metals. © 1990 Taylor & Francis Ltd.