分子动力学模拟金属纳米杆受压稳定性　

MOLECULAR DYNAMICS ON THE STABILITY OF METAL NANOROD UNDER AXIAL FORCE

纳米结构(包括纳米杆)的力学性能是纳米超微型器件设计的基础,分子动力学是研究纳米结构力学行为的有效方法.采用EAM势模拟金属铜纳米杆在轴向压力作用下的力学行为,结果表明,当外力较小时,纳米杆受压发生纵向收缩;当外力达到某一临界值时,纳米杆发生横向弯曲(即屈曲)行为;稳定的弯曲状态能继续承受外载;当外力继续增大时,纳米杆发生倾覆而失效.

The mechanical behavior of nanostructure(such as nanorod, nanowire) is the base of nanodevices design, and molecular dynamics simulation is a valid way investigating this behavior. The mechanical behavior of Cu nanorod under axial force is simulated by the embedded atom method(EAM). The simulation results show that the mechanical behavior in nanoscale is very different from that in macrosclae. The difference is resulted from size effect and surface effect. When the external axial force is not big enough, the nanorod contracts in length. When the force reaches the critical point, transverse bending happens to the rod, well-known as bucking. The stable bending nanorod still can endure external force. When the external force is too big, the nanorod collapses. The results also show that the metal nanorod is ductile.