晶体非线弹性变形的原子级模拟研究

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. 关键词： 晶体 弹性变形 分子静力学

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

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 presnted.