Abstract
Hyper-QC is a multiscale method based on the quasicontinuum (QC) method in which time is accelerated using hyperdynamics through the addition of a suitable bias potential. This paper describes the practical details of implementing and carrying out hyper-QC simulations and introduces a novel mechanism-based bias potential for deformation processes in face-centred cubic (fcc) systems. The factors limiting the maximum achievable acceleration are discussed. The method is demonstrated for nanoindentation into a thin film of single crystal fcc nickel at near experimental loading rates. Speed up factors as high as 10,000 are achieved. The simulations reveal a thermally activated dislocation nucleation mechanism with a logarithmic dependence on temperature and indenter velocity in agreement with a theoretical model.
Notes
No potential conflict of interest was reported by the authors.
1 Since all nodes must be co-located with atoms in the reference configuration, the atomic structure sets a lower limit on mesh refinement.
2 Atoms in the padding region whose positions are determined by interpolation are referred to as ‘dummy atoms’ in QC. Thus, in the present implementation dummy atoms are not allowed.