Atomistic submodel implementation and application within microstructure analysis by molecular dynamics

Abstract

Classical continuum mechanics faces substantial difficulties for adequately describe stress and strain distributions around microstructural material discontinuities such as crystallographic defects, voids, and grain boundaries. One way to improve the microstructural model is the development of the atomistic submodel that provides a minimal increase in the amount of atomistic data, but provides more accurate stress predictions without time consuming calculation of full atomistic model. In the proposed approach continuum model, discretized by finite elements, provides a displacement field for atoms on the edge of the simulation cell of the the atomistic submodel driven by molecular dynamics. The final result is the utilization of the best from both worlds, calculation speed of the constinuum mechanics using finite elements method and informing it with relevant material properties inferred from atomistic simulations by using molecular dynamics where it is the necessary.