Large-scale elastic-plastic indentation simulations via nonequilibrium molecular dynamics

Abstract

Nonequilibrium indentation simulations for two-dimensional crystals composed of up to 1036 800=720×1440 atoms are described. The forces used include smoothly truncated Lennard-Jones force laws, both with and without added embedded-atom contributions typical of copper or nickel. Both low and intermediate temperatures are considered over a wide range of indentor speeds. Typical microhardness yield strengths for these two-dimensional materials, force divided by projected area, exceed 10% of the shear modulus. For the most part these simulations were carried out on the 64-transputer SPRINT computer at Livermore.