期刊
JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE
卷 7, 期 6, 页码 1172-1181出版社
AMER SCIENTIFIC PUBLISHERS
DOI: 10.1166/jctn.2010.1469
关键词
Linear Elasticity; Material Science; Molecular Statics; Nanoindentation; Quasicontinuum Methods
类别
资金
- European Commission [MRTN-CT-2004-005583]
- MSHE [131/6PRUE/2005/7]
Our numerical approach to modeling elastic-plastic deformation comes back to the idea of the time-independent plasticity developed here at the molecular-statics level. We use a constitutive atomic model based on the second-moment approximation of the tight-binding potential coupled to a linear theory of elasticity solved simultaneously within the finite element method. Our model is applied to the nanoindentation problem for copper in which the indenter is represented by the equations of a sphere. For convenience the time-dependency of the nanoindentation problem is reduced to a quasi-static adiabatic scheme. A recurring theme in this paper is to determine the response of the proposed model for two differing systems: mono and polycrystalline copper. This paper discusses the force-depth response in terms of atomic bond-lengths, elastic-plastic deformations, and the instantaneous stiffness of the material. We report on an increased instantaneous stiffness of polycrystalline copper compared to that of its monocrystalline counterpart. From both a distinct and a comparative analysis of both systems, based on the relaxed positions of the atoms in the structure during the simulation, we deduce that plastic deformations at grain-boundaries are responsible for this change in the overall instantaneous stiffness of the material.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据