晶体非线弹性变形的原子级模拟研究

The nonlinear elastic behavior of crystalline solids:An atomistic simulation study

采用分子静力学结合量子修正Sutten-Chen型多体势研究了Ni单晶体在受单向拉伸和压缩载荷作用下的弹性响应.考虑了三种加载方式,即[001],[011]和[111]单向加载.模拟的结果表明:晶体在[011]单向加载下的弹性变形表现出强烈的非线性效应,然而沿[001]和[111]单向加载时,它的横向变形表现为各向同性.进一步讨论了杨氏模量和泊松比与应变的关系,并和第一性原理计算的结果做了比较.

In this paper, we employ molecular static approach with quantum corrected Sutten-Chen many-body potential to study the elastic responses of nickel monocrystal subjected to uniaxial tensile and compressive loading, and consider three different loadings, i.e., the [001], [011] and [ 111] loding. The simulated results show that strong nonlinear effects are found in the elastic behavior of monocrystal under the [011] loading, while the lateral deformations are essentially isotropic under [ 100] and [ 111 ] loadings. The further discussions are focused on the dependence of the Young＇ s moduli and Poisson＇ s ratios on the applied strain, and a brief comparison with first-principles calculations is also presented.