Wang L, Zhang H W, Deng X M
State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116024, People's Republic of China. Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208, USA.
J Phys Condens Matter. 2009 Jul 29;21(30):305301. doi: 10.1088/0953-8984/21/30/305301. Epub 2009 Jul 6.
The buckling behavior of single-walled carbon nanotubes completely filled with copper atoms under uniaxial compression is investigated using molecular dynamics simulations and compared with that modeled by continuum mechanics. The effects of geometrical characteristics, i.e. tube length, radius and chirality, on buckling deformations are explored separately. Results show that the behavior of encapsulated tubes is more complicated than that of empty ones due to the accommodation of the internal metal atoms. There are both similarities and differences between the results obtained by the molecular dynamics method and continuum mechanics. For a group of completely filled (10, 10) tubes with different length, the dependence of the critical strain on the tube length can be roughly divided into four different linear stages and is accompanied by a transition of the buckling mode from local to global. It is the competition between the evolution of the structure of metal atoms and the variation of the tube length that determines the critical strain. There exists a rather wide range of tube radii within which the critical strain has a weak dependence on tube radius, which differs from the observation for empty tubes. As compared with a zigzag tube of the same length and radius, an armchair tube has a lower critical strain but can be easily strengthened with the incorporation of internal metal atoms.
采用分子动力学模拟研究了完全填充铜原子的单壁碳纳米管在单轴压缩下的屈曲行为，并与连续介质力学模型进行了比较。分别探讨了几何特征（即管长、半径和手性）对屈曲变形的影响。结果表明，由于内部金属原子的容纳，封装管的行为比空管更为复杂。分子动力学方法和连续介质力学得到的结果既有相似之处，也有不同之处。对于一组不同长度的完全填充的（10,10）管，临界应变对管长的依赖性大致可分为四个不同的线性阶段，并伴随着屈曲模式从局部到整体的转变。金属原子结构的演变与管长的变化之间的竞争决定了临界应变。存在一个相当宽的管半径范围，在此范围内临界应变对管半径的依赖性较弱，这与空管的观察结果不同。与相同长度和半径的锯齿形管相比，扶手椅形管的临界应变较低，但通过引入内部金属原子可以很容易地得到强化。
