单壁碳纳米管非线性力学行为的数值模拟

单壁碳纳米管的力学行为是纳米复合材料和纳米器械的基本问题之一.使用有限元方法系统地研究了单壁碳纳米管的轴压和纯弯变形，并将有限元模拟结果和分子动力学模拟结果进行了比较.研究结果表明单壁碳纳米管的轴压屈曲载荷受直径变化的影响；单壁碳纳米管在弯曲载荷作用下的屈曲和后屈曲行为强烈地依赖于管长和管径的变化，合理地选择碳纳米管的弹性模量和壁厚，有限元方法能够很好地解释碳纳米管的屈曲机理.研究大尺度的纳米力学问题时，有限元方法将会成为更加准确、快捷的数值模拟方法.

Numerical simulation of nonlinear mechanical behaviour of single-walled carbon nanotubes

The mechanical behavior of single-walled carbon nanotubes (SCWNTs) is one of the basic properties of the nanotube composite and nano machinery. The axial and bending buckling behavior of SWCNTs is systematically investigated by finite element mothod(FEM) in this paper. The results of molecular dynamics and FEM simulations are compared. Simulation results show that the axial buckling loads are dependent strongly on the diameter, and the buckling and postbuckling behavior of SWCNTs under bending depends strongly on the length and radii of the tube. With appropriate choice of Young's modulus and tube thickness, the FEM simulation provides some useful insight into the buckling mechanism of carbon nanotubes. The finite element method turns out to be a new, forthright and precise method for the simulation in solving large-scale nano-mechanics problems.