Atomistic vs. continuum models of nanoporous elastic solid: Stress fields, size-dependent effective stiffness and surface constants

The method of classical molecular dynamics (MD) is applied to study the stress fields and effective elastic stiffness tensor of nanoporous materials. A continuum model for a nanoporous solid involving a surface layer of sub-nanometer thickness is proposed. Systematic comparisons of the unit cell atomistic MD results are performed with two continuum models, one based on the finite element analysis and another based on the multipole series expansion. This comparison validates the continuum models, shows their applicability limits, and provides reliable identification of the surface elastic constants.

Automated summary

The method of classical molecular dynamics is used to analyze the stress fields and effective elastic stiffness tensor of nanoporous materials. A continuum model incorporating a surface layer of sub-nanometer thickness is proposed. Systematic comparisons between atomistic molecular dynamics results and two continuum models validate the latter, determine their applicability limits, and accurately identify the surface elastic constants.