Molecular dynamic modelling of the combined influence from strain rate and temperature at tensile loading of nanosized single crystal Cu beams

Abstract

It is well-known and experimentally confirmed that the mechanical response of small enough structures, with linear measures typically below about 100 nm, differs from the response at macro scale. In addition to size effects, the crystallographic orientation of the material becomes increasingly important at this scale. This paper investigates the combined influence of strain rate and temperature on nanosized, initially defect-free, single crystal Cu beams of square cross-sections subjected to displacement-controlled tensile loading. Additionally, the influence of crystallographic orientation is investigated for loading along the [100], [110] or [111] direction. The simulations performed were 3D molecular dynamic simulations. Both the elastic and the plastic behaviours were analysed, and stress-strain curves and dislocation evolution were monitored in detail during loading.