薄壁零件铣削加工系统动态特性测试与分析

Test and Analysis for Dynamic Characteristics of Thin-walled Components Milling System

为预测薄壁件的铣削加工稳定性,采用有限元模态分析方法和试验模态分析方法,分别分析刀具子系统和工件子系统的动态特性。根据薄壁零件的振型模态,划分表示工件在加工过程中动态特性变化的不同加工阶段、选取能够在刀具切削位置激起振动位移的高阶动态频响模型作为预测切削稳定性的有效振型。对于薄壁零件的铣削加工,建立由刀具子系统和工件子系统相互作用的、考虑加工阶段并取决于有效振型的加工系统结构传递函数。稳定性预测结果与试验结果基本相符,证明系统传递函数的测定精度较高。

To predict the stability of the thin-walled components milling, the dynamic characteristics of the spindle-tool set and the workpiece are analysed respectively by the finite element modal analysis method and the experimental modal analysis method. The flexible workpiece vibration modes are available for partitioning the distinct machining stages that denote the dynamic variation characteristics of the workpiece in the process and for selecting the high-order dynamic frequency modes that can produce the displacement at the tool-cutting position as the virtual vibration modes to predict the cutting stability. For the thin-walled components milling, a system structural transfer function is proposed, which consists of a sub-section that describes the interaction of the spindle-tool set model and the workpiece dynamics, considers the machining stages position, and depends on the virtual vibration modes. The stability prediction results are in good agreement of the experimental results. The high precision of the system transfer function is proved.