单壁氮化硼纳米管压缩特性的分子动力学模拟  

Compression of BN Nanotubes:A Molecular Dynamics Study

作　　者：荆宇航[1] 孟庆元[1] 

机构地区：[1]哈尔滨工业大学航天科学与力学系,黑龙江哈尔滨150001

出　　处：《计算物理》2009年第2期281-286,共6页Chinese Journal of Computational Physics

基　　金：国家自然科学基金(10772062)资助项目

摘　　要：采用分子动力学方法,分别模拟完好的和含有缺陷的(7,7)扶手椅型氮化硼纳米管的轴向压缩过程.原子间的相互作用采用Tersoff多体势函数来描述.为验证结果的可靠性,同时针对(7,7)扶手椅型碳纳米管进行对比计算.结果表明,氮化硼纳米管的压缩失效模式同碳纳米管相同,均表现为管壁的局部屈曲.发现纳米管的压缩强度,如临界轴向内力在低温下受温度影响明显,并且和应变率的大小有关.然而,应变率对纳米管的弹性变形没有影响.另外,还发现空位缺陷降低了纳米管的力学性能.与完好的纳米管相比,含有缺陷的纳米管轴向压缩强度对于温度的影响并不敏感.With molecular dynamics （MD） method, axial compression of both perfect and defective armchair （7, 7） single-walled BN nanotubes is simulated. Tersoff potential is used to simulate interaction among atoms. To verify the method, armchair （7, 7） single-walled carbon nanotubes are calculated. It shows that compressive failure mode of BN nanotubes is almost the same of carbon nanotubes, in which locally-buckling on walls are observed. It is revealed that compressive strength of nanotubes, such as critical axial load, is related to applied strain rate and is affected by temperature especially at low temperatures. However, elastic deformation of nanotubes is not affected by strain rate. It is found that vacancy defects are quite harmful to mechanical properties. Compared with perfect nanotubes, compressive axial strength of defective nanotubes is not affected by temperature significantly.

关 键 词：分子动力学 氮化硼纳米管 压缩强度 应变率 缺陷 

分 类 号：O613[理学—无机化学] TB383[理学—化学]