Concurrent Atomistic-Continuum Model

Image created by Jiaxi Zhang

Abstract

Concurrent multiscale models that couple atomistic and continuum calculations are useful for extending the spatial limitations of atomistic models, as well as for deriving effective continuum models. This work develops a concurrent atomistic-continuum computational model with an embedded crack in the atomistic domain. Molecular dynamics (MD) simulations are conducted in the atomistic domain, while the continuum domain is modeled using the finite element (FE) method. To bridge the time scale difference, the MD model is augmented by a novel strain-boost hyperdynamics accelerated time marching scheme. The concurrent model is used to evaluate the free energy density function for phase field modeling of crack propagation in crystalline materials.

Subhendu Chakraborty and Jiaxi Zhang

Coupled framework for atomistic-continuum concurrent models
Spatial decomposition of the domain
Bridging the temporal scale of atomistic and continuum domain using Hyperdynamics
Strain rate effect on evolution of dislocation microstructure
Strain rate effect on plastic deformation mechanisms
Developing crack propagation law from coupled concurrent model
Propagation of Dislocations from Atomistic to Continuum domain

Papers:

J. Zhang, S. Chakraborty and S. Ghosh, “Concurrent atomistic-continuum model for developing self-consistent elastic constitutive modeling of crystalline solids with cracks”, International Journal Multiscale Computational Engineering, Vol. 15, No. 2, pp. 99-119.
S. Chakraborty, J. Zhang and S. Ghosh,“Accelerated molecular dynamics simulations for characterizing plastic deformation in crystalline materials with cracks”, Computational Materials Science, Vol. 121, pp. 23-36, (Editor’s Choice).