The main characteristics of Frank–Read sources, used in a mechanism-based discrete dislocation plasticity analysis, were estimated by using a recently developed non-singular continuum elastic theory for dislocations. The critical nucleation stress, τnuc, could be determined more accurately, because dislocation core effects were considered precisely by atomistically informing the dislocation dynamics simulations. The nucleation time was calculated, and compared with previous predictions. The dependence of the drag coefficient of dislocations, upon dislocation line orientation, was considered. This affected the nucleation time and the shape of the emitted dislocation loop. In mechanism-based discrete dislocation plasticity simulations, the τnuc used for sources was calculated, based upon the assumption of an infinite domain. However, the critical nucleation stress was really affected by other Frank–Read sources. It was proposed here that the critical nucleation stress should be modified by considering the effects of other dislocation sources. To this end, it was proposed that τnuc be determined for a Frank–Read source in a finite cell with periodic boundary conditions.

A Dislocation-Dynamics-Based Derivation of the Frank–Read Source Characteristics for Discrete Dislocation Plasticity. S.S.Shishvan, S.Mohammadi, M.Rahimian: Modelling and Simulation in Materials Science and Engineering, 2008, 16[7], 075002