Local stress calculation in simulations of multicomponent systems

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)8467-8479
Journal / PublicationJournal of Computational Physics
Volume228
Issue number22
Online published1 Sep 2009
Publication statusPublished - 1 Dec 2009
Externally publishedYes

Abstract

The virial and Hardy methods provide accurate local stresses for single component materials such as monatomic metals. In contrast to the elemental material case, both methods provide poor estimates of the local stress for multicomponent materials. Using binary materials such as CaO, SiC and AlN and homogeneous strain, we demonstrate that there are several sources for the slow convergence of the virial and Hardy local stresses to the bulk values. Different approaches such as enforced stoichiometry, atomic localization functions and the atomic voronoi volume are used to improve the convergence and increase the spatial resolution of the local stress. The virial method with enforced stoichiometry and atomic voronoi volumes is the most accurate, giving exact stress values by the first atomic shell. In the general case, not assuming stoichiometry, the virial method with localization functions converge to 93% of the bulk value by the third atomic shell. This work may be particularly useful for the real-time description of stresses in simulations of shock waves and deformation dynamics.

Research Area(s)

  • Cauchy stress, Local stress, Localization function, Molecular dynamics, Shock waves, Virial stress