拉伸载荷作用下单晶铝柱动态断裂过程的分子动力学模拟研究（英文）

Molecular dynamics simulation for dynamic failure process of single crystal aluminum column under tension

运用LAMMPS中的Fortran语言自编程功能建立了单晶铝柱在拉伸载荷作用下的分子动力学仿真模型,采用镶嵌原子势(EAM)势函数模拟了室温下单晶铝柱的动态断裂过程。从应力应变关系、原子构型和相变等方面解释了拉伸过程中的力学性能。位错是单晶铝塑性变形的主要原因,位错相互作用引起塑性硬化和晶体破坏,晶体在载荷作用下沿{111}面滑移,滑移面与理论结果相符合。

The molecular dynamic （MD） model for the single crystal aluminum at the temperature of 300 K is established based on user-defined FORTRAN functionin LAMMPS,where the atomic interactionis described through embedded atom method （EAM）. From the stress-strain curve, atomic configurations and phase transformation, corresponding to the critical points at which are also figured. Common Neighbor Analysis （CNA） is used to express the evolution of phase transformation, the mechanical properties are illustrated. It proves that the dislocation is the main cause of plastic deformation of the single crystal aluminum, and that interaction dislocation contributes most to the plastic hardening and the crystal failure, which agrees well with the conclusions predicated by the theory of FCC slips along the [ 111 ] crystal face.