有孔纳米单晶铜薄膜拉伸断裂特性的分子动力学模拟

运用分子动力学方法模拟有孔纳米单晶铜薄膜的拉伸断裂过程.通过施加拉伸应变驱动原子运动和小孔变形,展示有孔纳米单晶铜薄膜随应变增加的原子位形直观分布;超过弹性极限后,位错发生于小孔的应力集中处.计算所得原子平均能量随变形的增长趋势,结果表明,有孔纳米单晶铜薄膜的变形机制可以显著地分为三个阶段,弹性延伸、塑性滑移、沿位错线开裂.

MOLECULAR DYNAMICS SIMULATION OF FRACTURE BEHAVIOR OF THE SINGLE-CRYSTALLINE NANO-COPPER FILM WITH A HOLE

The fracture behavior of a hole in the single-crystalline nano-copper film was simulated by molecular dynamics method with the embedded atom potential. The atom movement of the film was motivated by tension strain with scale method and the clear atom deformation image was obtained; once the strain exceeded the elastic limit, the dislocations began at the stress concentration position of the hole; the changing trend of the atom average energy by the increasing of strain shows that the whole deformation of this single-crystalline nano-copper film with a hole can be divided into three stages: elastic extending, plastic glide and fracture along the dislocation line, and every stage represented a different physical mechanism.