不同温度下纳米单晶铜杆拉伸的分子动力学模拟

研究对不同温度下的纳米单晶铜杆的拉伸过程进行仿真模拟。模拟应用了分子动力学方法,所用势函数为镶嵌原子势(EAM),时间积分为Verlet速度算法,对构件的温度控制用速度标定法。对弛豫阶段在不同温度时的能量演化做了详细分析,采用对端面原子直接加力的方法施加外载荷进行拉伸模拟。根据模拟结果,对在不同温度下纳米单晶铜杆的应力-应变关系,温度对纳米单晶铜杆的破坏应力及弹性模量的影响等进行了分析和解释。

Molecular dynamics simulations of tensile test of single crystal copper nanobar under different temperatures

Tensile tests of a nanoscale single crystal copper bar under different temperatures are simulated.In the simulations,molecular dynamics simulation method and embedded atom potential function are adopted.The numerical integration procedure for time variable is Verlet-velocity algorithm and the system temperature is controlled by velocity scaling method.At first,we present some details of the relaxation processes under different temperatures.Then the external loads are acted directly on the atoms of the bottom end of the bar and the tensile simulation is operated.According to the simulation results,the relationship of stress-strain of the nanoscale single crystal copper bar,the influence of temperatures on the failure stress and embedded atom potential function,Young’s modulus etc.are explained.