金属切削过程中微观应力及宏观切削力演变规律研究

Study on Evolution Law of Micro Stress and Macro Cutting Force During Metal Cutting

使用Python语言将Voronoi图导入ABAQUS软件,建立了二维微观切削有限元模型。考虑应变硬化效应、应变率与温度效应对切削的影响,并用Cohesive单元模拟晶粒与晶粒之间的晶界,获得了切削过程中切屑晶粒、切屑晶界和加工表面的应力变化规律。结果表明,切削过程中晶界的应力大于晶粒的应力,切屑的晶界应力大于部件的晶界应力;晶粒被挤压变得细长,切削方向上的晶界变短,非切削方向上的晶界变长。切削位置的晶界越多,切削力就相对越小,晶界越少,切削力相对越大。通过对比宏观模型的结果,推测出切削力产生波动的原因。

A two-dimensional micro cutting finite element model is established by importing Voronoi diagram into ABAQUS with Python language.Considering the effects of strain hardening, strain rate and temperature on cutting, a Cohesive element is used to simulate the grain boundary between grains, and the stress variation of grain on chip, grain boundary on chip, and machining surface during cutting is obtained.The results show that the stress on grain boundary is greater than that on grain, and the stress on grain boundary of chip is greater than that on component.Grains are squeezed and become elongated, grain boundaries become shorter in the cutting direction and longer in the non-cutting direction.The more grain boundaries in the cutting position, the smaller the cutting force will be, and the less grain boundaries, the greater the cutting force will be.The reason of cutting force fluctuation is deduced by comparing the results of macro model.