On the consideration of climb in discrete dislocation dynamics

Abstract

A concept is outlined to incorporate dislocation climb in a discretethreedimensional model of dislocation dynamics. Each dislocationline consists of a sequence of interconnected piecewise straightsegments which are embedded in a homogeneous linear elastic medium.The dynamics are described by solving Newton's equation of motionfor each portion of dislocation. Non-conservative dislocation motionis introduced by considering the osmotic force that arises from emittingor adsorbing point defects at the climbing segment. The osmotic forceon each segment depends on the local point defect concentration.The mechanical structure evolution law must thus be complementedwith a chemical structure evolution equation. Corresponding formulationsare derived using the continuity equation and Fick's first law ofdiffusion.