摘要
用分子动力学方法模拟纳米铜杆的拉伸过程 ,用有限变形列式表征纳米杆单向拉伸屈服前的应力和应变 .结果表明 :铜单晶纳米杆屈服前的最大弹性应变约为0 .1 1 ;用有限变形应力、应变表征变形过程和材料性质与通常名义应力、应变表征相比有明显不同 ;纳米杆泊松比随应变增加而减弱 ,并从物理上解释了这一现象的原因 .
The axial extension simulation of copper nanorod was performed by molecular dynamics method with the embedded atom potential, and the stress strain relation in the elastic stage was manifested with the finite deformation formulation. It is found that yield strain is about 0.11; the deformation process and material property described by stress and strain of finite deformation is significantly different from the description of nominal stress and strain. The Poisson ratio decreases with increasing strain and the physical mechanism of this phenomenon is discussed.
基金
国家自然科学基金资助项目(10 172 0 81)
关键词
分子动力学
纳米铜杆
有限变形
泊松比
molecular dynamics
copper nanorod
finite deformation
Poisson ratio
