基于RCSA和二阶有限差分法的刀尖点频响函数预测研究

Prediction of Tool Tip Frequency Response Function Based on RCSA and Second-order Finite Difference Method

铣削系统动态特性参数对切削过程的稳定性起着非常重要的作用,而获取由刀具尖点频响函数表示的该参数是实现无颤振切削的先决条件。基于响应耦合子结构法,将铣削系统划分为主轴刀柄和刀具两个子系统,将刀具子系统进一步细分为刀杆和刀齿两个子系统。综合运用模态锤击实验和二阶有限差分法等辨析方法,考虑旋转响应的主轴刀柄末端频响函数,将铣刀简化为欧拉-伯努利梁,计算出铣刀子结构的频响函数,通过响应耦合获得铣削系统刀尖点频响函数,模型的正确性得到了实验验证。

The dynamic characteristic parameter of milling system plays a very important role in the stability of cutting process,and obtaining the parameter expressed by the tool tip frequency response function is the prerequisite for realizing the non-flutter cutting.Based on the response coupling substructure method,the milling system is divided into two subsystems:spindle shank and tool.The tool subsystem is further subdivided into two subsystems:tool bar and tool teeth.The study conducts modal hammer experiment and second-order finite difference method,simplifies milling cutter into Euler-Bernoulli beam,calculates the frequency response function of milling cutter substructure,obtains the tool tip frequency response function of milling system through response coupling,and verifies the correctness of the model by experiments.