Investigation of the mechanical responses of copper nanowires based on molecular dynamics and coarse-grained molecular dynamics

The mesoscale coarse-grained molecular dynamics (CG-MD) models for copper nanowires with different crystallographic orientations are developed via increasing the integration time step and grouping a certain number of atoms into one mesoscale particle. The tensile and torsional responses of copper nanowires at various temperatures and loading rates are then studied using the CG-MD and molecular dynamics (MD) simulations. In the tensile cases, the CG-MD simulations yield the tendency of Young’s modulus with a good agreement with that by the MD. For the torsional loading, the relation between loading rate and critical angle by the CG-MD is also in line with that by the MD, while the CG-MD predictions for low temperatures are not in close agreement with those by the MD. Although the CG-MD model could not perfectly fit the results from the MD and requires further improvement, it could be used as a starting point to evaluate the mechanical response of nanowire with less computational expenses than the MD model.