An investigation was reported of the probability and the probability density of thermal activation of stress-driven dislocation processes, as simulated using molecular dynamics. Stochastic analyses of the survival probability were found to lead to simple relationships between the loading history and the distribution of the interaction time and strength. It was shown that the determination of the activation energy associated to a thermally activated event could be achieved by a reduction of the stochastic process to a process obeying the Poisson's distribution, preserving the activation probability at the survival time. The method was applied to the kink-pair mechanism for screw dislocations in iron. Predictions were compared with experimental results and with other methods reported in the literature, which allowed the difference in the approximations and in the assumptions considered in these models to be underlined.

Determination of the Activation Energy by Stochastic Analyses of Molecular Dynamics Simulations of Dislocation Processes. G.Monnet: Philosophical Magazine, 2011, 91[29], 3810-29