单、双原子空位缺陷对扶手椅型单层碳纳米管屈曲性能的不同影响

采用分子动力学方法，对完善和含缺陷扶手椅型单层碳纳米管进行轴向压缩的数值模拟，对比研究三种不同的温度环境下单、双原子空位缺陷对碳纳米管轴压变形性能的特殊影响.研究结果表明管壁缺陷显著降低了纳米管低温时的承载能力，由于单原子空位缺陷造成的特殊应力集中效应会引发纳米管过早发生局部屈曲，单原子缺陷管的屈曲强度反而小于双原子管的屈曲强度. 关键词： 分子动力学 碳纳米管 屈曲 缺陷

Influences of atom vacancies on buckling properties of armchair single-walled carbon nanotubes shown by molecular dynamics simulation

Molecular dynamics simulations are employed to simulate the axial compression of both perfect and defective armchair single-walled carbon nanotubes (SWCNTs). Three temperature conditions are considered. It is revealed that the vacancy defects in SWCNTs have remarkable influences on their buckling properties, especially at low temperature. It is noticed that the single vacancy defect leads to excessive stress concentration, as a result of which the local buckling occurs easily at the defective position. Thus, the (7, 7) tube with single vacancies seems inferior to that with double vacancies.