碳、氮化硼纳米管与纳米豆荚的拉伸与压缩特性

Tensile and Compressive Properties for C,BN Nanotubes and Nanopeapods

采用分子动力学方法,模拟了(10,10)碳、氮化硼纳米管及纳米豆荚的轴向拉伸与压缩.根据模拟结果,讨论了它们拉伸与压缩力学特性的差异.研究表明:①碳纳米管及碳豆荚的拉伸失效为剪切破坏,而氮化硼管及氮化硼豆荚为拉断模式;②碳管及碳豆荚的拉伸性能无明显差异,均明显优于氮化硼管及氮化硼豆荚,氮化硼豆荚的拉伸性能优于氮化硼管;③碳管及碳豆荚的压缩失效形式为管壁的局部屈曲,而氮化硼管及氮化硼豆荚为管壁原子的重构;④碳与氮化硼纳米管,以及碳与氮化硼豆荚的压缩性能分别相当,但两种豆荚的压缩性能明显优于两种空纳米管.

By using molecular dynamics（MD） method, the axial tension and compression of the （10, 10） carbon, BN nanotubes and nanopeapods were simulated. According to the simulative results, the differences of their tensile and compressive properties were analyzed and discussed. The results show that ①carbon tube and peapod under tension have the shear-failure mode, and the BN tube and peapod the tension-failure mode;②the carbon tube and peapod do not have obvious difference and are both superior to the BN tube and peapod in tensile properties, and the tensile properties of the BN peapod are superior to those of the hollow BN tube; ③ the compressive failure of the carbon tube and peapod can be attributed to the locally-buckling on their walls, while the failure of the BN tube and peapod is the local reconfiguration of atoms on their walls; ④carbon and BN nanotubes, as well as carbon and BN nanopeapods, have the comparative compressive properties, and the two kinds of nanopeapods are much better than the two kinds of hollow nanotubes in compressive properties.