碳纳米管在简单荷载作用下的变形屈曲行为研究

采用分子动力学方法研究了不同螺旋性的单壁碳纳米管在轴压、扭转和外压分别作用下的变形屈曲行为。针对每种加载形式，给出了宏观形式的内力一变形曲线来反映碳原子间相互作用力的变化与碳管变形量之间的关系。对碳管在这三种不同荷载作用下的失稳特性、微观结构和应变能的变化进行了详细的分析。结合经典弹性理论和本文的模拟结果，得出了单壁碳纳米管的等效壁厚、弹性模量和Poisson比。另外，通过对比不同螺旋性碳管的模拟结果，讨论了螺旋性对碳纳米管力学行为的影响。文中采用的势能函数为Brenner多体势。

Buckling of Single Walled Carbon Nanotubes under Destabilizing Loads

Buckling analysis for single walled carbon nanotubes with (n,n)- and (n,0)- helicity, when acted upon by the destabilizing loads of axial compression, torsion and external pressure, was presented. Based on the multi body Brenner's potential, the molecular dynamics simulation approach was used to determine the postbuckling equilibrium paths, variation of strain energy and buckling modes. From the simulation results, an appropriate set of effective mechanical properties and equivalent wall thickness of each tube were obtained. The effects of helicity on the mechanical behavior of nanotubes were also studied.