KINEMATIC GENERATION OF DISLOCATIONS

In this letter we present evidence from computer simulations that edge dislocations can be generated by purely kinematic processes, in the a bsence of more conventional dislocation sources. New dislocation pairs may be generated near high-velocity dislocations. These kinematic pro cesses are only active under high stresses but may be important under shock loading or under other conditions where a very high strain rate is obtained. This dislocation generation becomes possible because the sign of the force between edge dislocations changes when the dislocati on velocity exceeds the Rayleigh velocity.