飞机蒙皮镜像铣加工稳定性分析

镜像铣技术是近年来提出的一种针对大尺寸薄壁件的加工方法，其加工环保、高效，具有逐步取代传统化铣加工的趋势。针对飞机蒙皮镜像铣加工过程中的颤振问题，首先，根据镜像铣加工特点，建立工艺系统颤振稳定性极限的预测模型；其次，通过有限元方法对蒙皮工件进行模态分析，分析蒙皮不同加工位置动力学特性变化导致的铣削稳定性变化，并通过实验测量获取工件动力学参数，对不同加工位置的稳定性做出预测；最后，开展加工实验，基于非接触测量方法，在线监测镜像铣加工区域的振动位移，通过时、频域信号对加工状态进行辨识，揭示了镜像铣加工过程的稳定性变化及失稳机制，验证了所提方法的准确性，在工程领域具有较高的实用价值。

Stability analysis of aircraft skin mirror milling process

In recent years, the mirror milling technology has been developed for processing large-sized thin floor parts, which is environmentally friendly and efficient, and is growing to replace the traditional chemical milling process. To overcome the problem of chatter in aircraft mirror milling, a method is proposed to prevent the occurrence of chatter by optimizing the cutting parameters. According to the characteristics of mirror milling process, a prediction model is established for predicting stability limit of mirror milling. A modal analysis of skin parts is performed by using the finite element method to analyze the changes of milling stability caused by the changes of the dynamic characteristics of different processing positions of the skin. The dynamic parameters of the workpiece are obtained through experimental measurements, and the chatter stability of different processing positions is obtained. Experiments are carried out using non-contact measurement method to monitor the vibration displacement in processing area on-line. The processing status is identified with time-frequency domain synthesis analysis. The results reveal the stability changes during mirror milling process and the instability mechanism. Effectiveness of the method proposed is validated to be effective, showing great applicability in practice.