基于RCSA的刀尖频响函数预测方法

Frequency Response Function Prediction Method of Tool Tip Based on RCSA

为快速获取构建铣床稳定性叶瓣图所需的主轴—刀柄—刀具系统频响函数,提出一种有限元和响应耦合子结构分析法(RCSA)相结合的预测方法。以某型号主轴系统为研究对象,利用有限元法分别计算主轴、刀柄、刀具端点频响函数,再使用RCSA分别耦合主轴—刀柄结合面、刀柄—刀具结合面,最终得到主轴—刀柄—刀具系统刀尖频响函数。将得到的频响函数与理论算法以及完全有限元方法对比,在5000Hz以内,前7阶模态最大误差不超过15%。该方法可以在机床更换刀柄或刀具时只计算对应部分的频响函数,从而实现主轴—刀柄—刀具系统刀尖频响函数的快速预测。

In order to quickly obtain the frequency response function of the spindle-handle-tool system for constructing the stability lobe diagram of milling machine,a prediction method combining finite element method and receptance coupled substructure analysis(RCSA)is proposed.Taking a certain type of spindle system as the research object,the frequency response functions of spindle,tool holder and tool are calculated by finite element method.Afterwards,RCSA is used to couple the spindle-tool holder interface and tool holder-tool interface respectively.Finally,the tool tip frequency response functions of the spindle-holder-tool system are obtained.Comparing the obtained frequency response function with those from the theoretical algorithm and the full finite element method,the maximum error of the first seven modes is less than 15%within 5000Hz.This method can only calculate the frequency response function of the corresponding part when the tool holder or tool is replaced,thus realizing the fast prediction of the frequency response function of the tool tip of the spindle-tool holder-tool system.