Chatter reliability prediction of side milling blisk

整体叶盘侧铣加工颤振可靠性预测

¹ Key Laboratory of High Performance Manufacturing for Aero Engine, Ministry of Industry and Information Technology, Northwestern Polytechnical University, Xi'an 710072, China
² School of Mechanical Engineering, Inner Mongolia University of Technology, Hohhot 010051, China
³ School of Aeronautics, Inner Mongolia University of Technology, Hohhot 010051, China

Received: 15 June 2020

Abstract

During the blisk side milling, the blade is thin and the tool suspension length is large, which is easy to occur milling system chatter. The wavy surface left by chatter has great effect on the surface roughness and service performance of the aero-engine blisk. To accurately predict the stability of the blisk side milling, the influence of random variables on the machining stability was considered. In this paper, the chatter reliability model of the blisk side milling system was established using the first-order second-moment method. The model takes structural parameters and spindle speed as random variables and chatter frequency as intermediate variables. The chatter reliability model was used to draw the reliability lobe diagram, which can be used to divide the machining reliability area. The effectiveness of this method was verified by experiments and compared with Monte Carlo method. The validation results showed that the reliability lobe diagram can be used to determine the stability probability prediction of blisk side milling and can replace the traditional stability lobe diagram.

摘要

整体叶盘侧铣加工中，叶片薄、刀具悬长大，极易发生颤振。颤振留下的波纹面，对整体叶盘的表面粗糙度及服役性能影响极大。为了准确预测整体叶盘侧铣加工的稳定性，考虑随机变量对加工稳定性的影响。应用动态结构系统的可靠性分析法——一次二阶矩法，建立了整体叶盘侧铣加工系统的颤振可靠性模型；该模型以结构参数和主轴转速为随机变量，以颤振频率为中间变量。利用颤振可靠性模型绘制可靠性叶瓣图，该图可用于划分加工可靠性区域。通过实例验证了该方法的有效性，并与蒙特卡罗法进行对比。验证结果表明可靠性叶瓣图可用于确定侧铣加工的稳定性概率预测，可以代替传统的稳定性叶瓣图。