时变因素作用下薄壁筒工件车削振动特性与实验

Vibration characteristics and experiments of thin⁃walled cylinders in turning process with time⁃varying factors

针对薄壁筒类工件的切削颤振问题,采用理论建模、数值仿真和实验测试相结合的方法,研究切削过程中时变工件厚度和切削位置对薄壁筒振动特性的影响规律。利用有限元法建立主轴⁃卡盘⁃工件工艺系统模型,分析不同壁厚、切削力位置对薄壁筒切削系统的固有模态、频率响应函数的影响。结合模态实验与切削振动实验表明:薄壁筒周向壳体模态对于壁厚的变化更为敏感,且沿工件轴向不同切削位置处工艺系统的振动响应及其主振模态有所不同;切削加工表面出现的沟槽、鱼鳞状等颤振纹理分别与工艺系统的低阶轴向梁振型、周向壳振型相关。研究结果对薄壁筒切削颤振的预测与抑制具有理论指导意义。

In view of the cutting chatter problem of thin⁃walled cylindrical workpieces,a combination of theoretical modeling,numerical simulation and experimental testing was adopted to study the influence of time⁃varying workpiece thickness and cutting position on the vibration characteristics of thin⁃walled cylindrical workpieces during the cutting process.The finite element method was used to establish the spindle⁃chuck⁃workpiece process system model.The influences of different wall thicknesses and cutting positions on the vibration mode and frequency response function of the thin⁃walled cylinder cutting system were analyzed.Through the modal experiment and the cutting vibration test,it showed that the shell mode of the thin⁃walled cylinder was more sensitive to the change of wall thickness,and the vibration response and main vibration mode of the process system at different cutting positions along the workpiece axis were different.It also verified that chatter textures of fish scales and grooves left on the surface were related to the low⁃order axial beam mode and circumferential shell mode of the thin⁃walled cylinder.The research results have a guiding effect on the prediction and suppression of chatter in machining of thin⁃walled workpieces.