Simulation of grain boundary sliding based on mechanics at atomic scale

Molecular dynamics (MD) and statics simulations are being increasingly used to model the behavior of systems at the atomic scale, where atomistic details play a critical role such as in grain boundary sliding. In the last few years atomic simulations have gone beyond the realm of understanding the effects of a few atoms to that of systems of millions of atoms. Even these simulations, which demand extensive computational resources, may not be able to adequately represent the behavior of systems of interest. This necessitates a multi-scale approach to such problems. In this paper, we present the atomistic simulation studies of grain boundary sliding of symmetric tilt grain boundaries in aluminum. The simulations are in agreement with experimental results and show a clear dependence of magnitude of sliding on grain boundary energy. Asymptotic expansion homogenization (AEH) is a mathematically rigorous approach to homogenization of periodic structures, which has been used extensively in composites and porous media. We propose a methodology to adapt AEH technique to atomic scale. Refs. 2 (author)