(1. 河海大学 土木工程学院， 南京 210098；
2. 浙江大学 力学系， 杭州 310027)
摘 要: 基于镶嵌原子势采用分子动力学方法研究了纳米镍单晶一维纳米丝、 二维纳米薄膜和三维纳米固体的拉伸变形破坏过程和力学行为与性能，分析了3类典型纳米金属材料的本征应力、 初始能量状态和变形机制以及破坏过程中的能量和应力变化， 讨论了自由表面对纳米金属材料力学行为和性能的影响。模拟得到镍单晶纳米丝、 薄膜和三维固体的弹性模量分别为145.45、 186.6和122.03 GPa； 断裂强度分别为22.293、 21.08和19.98 GPa； 纳米丝和固体的破坏中出现短暂屈服， 屈服强度分别为14.451和13.67 GPa， 纳米薄膜的断裂无屈服。
关键字: 纳米镍； 力学行为； 力学性能； 分子动力学；表面效应
three kinds of nano-scale materials made of
monocrystalline nickel
（1. College of Civil Engineering, Hohai University, Nanjing 210098, China;
2. Department of Mechanics, Zhejiang University, Hangzhou 310027, China）
Abstract: The failure process, mechanical behavior and properties of nano-scale nickel wire, film and block were studied by molecular dynamics method based on embedded atomic potential. The initial energy and stress, deformation process, variation of energy and atomic stress under tension in three kinds of nano materials were analyzed, respectively. The simulation results show the surface effects on mechanical behavior and properties of nano materials, and the constitutive relationship and elastic modulus (nano wire: 145.45 GPa; film: 186.6 GPa; block: 122.03 GPa), yielding strength (wire: 14.451 GPa; block: 13.67 GPa) and fracture strength (wire: 22.293 GPa; film: 21.08 GPa; block: 19.98 GPa) of each kind of nano materials are obtained.
Key words: nano nickel; mechanical behavior; mechanical properties; molecular dynamics; surface effects
