基于准连续介质理论的单晶铜纳米切削过程仿真

Simulating Nanometric Cutting Mechanism of Single-crystal Copper with Quasicontinuum Numerical Method

为了提高计算精度和扩大计算尺寸,克服分子动力学模拟方法计算效率低、模拟尺寸小、边界条件影响大等特点,本文采用多尺度准连续介质力学数值方法对单晶铜纳米切削过程进行仿真,探究单晶铜的纳米切削机理。验证了不同的刀具前角、切削厚度对切削过程中的位错、切削力和残余应力的影响。实验结果表明,当采用同一把刀具时,随着切削厚度的增加切削过程中的切削比能逐渐减小而位错深度、残余应力均相应增加。当采用同一个切削厚度,不同的刀具前角时发现,采用负前角切削过程中的切削力波动范围最大。

The paper uses the quasicontinuum numerical method to study the nanometric cutting mechanism ofsingle-crystal copper so as to improve its precision and expand its simulation size, avoiding the disadvantages of the molecular dynamics method, such as inefficiency, small simulation size and low-accuracy computation. The paper simulates the effects of the rake angle and cutting thickness of the nanometric cutting mechanism on the dislocation propagation, cutting force and residual stress of single-crystal copper. The simulation results show that： when the nanometric cutting mechanism uses the same tool, its specific cutting energy decreases gradually, whereas its depth of dislocation and residual stress increase accordingly. However, when the cutting thickness is the same, the fluctu- ation range of cutting force is maximum with the negative rake angle.