A method of milling chatter recognition by change of the power spectrum energy ratio in process of monitoring and processing is proposed. This objective is acheived by measuring the milling force and vibration signals under several cutting conditions. Experimental results show that main character of the power spectrum of signals when chatter happen,corresponding chatter frequency occurs evenly sapacing on both sides of the spindle rotation frequency, cutting frequency and their harmonics. On condition that the power value of the dominant chatter frequency is beyond a certain threshold, chatter occured, otherwise no chatter happened. According to the analytical model for regenerative chatter established and the experimental data obtained in the study, the frequeney response function and cutting force coefficient, based on which the stability curve is drawn. Combined with the method of chatter recognition, accuracy of dynamics model is verified, and can provide reference for slection of reasonable processing parameters and vibration monitoring in actual processing.%颤振是刀具与工件之间剧烈的自激振动,是影响工件表面质量与刀具磨损的重要因素.通过高速铣削试验,对加工过程中铣削力与振动信号进行分析,给出了一种通过监测加工过程中信号功率谱能量比变化来识别颤振的方法.试验结果表明:颤振发生时信号功率谱最主要的特性是在主轴转动频率、切削频率及其谐波两边等间距处会出现相应的颤振频率,当主颤振频率处的能量超过一定的阈值时,加工系统颤振,否则,无颤振.建立了颤振动力学模型,通过试验获得了铣削系统频响函数和铣削力系数,绘制了铣削加工稳定性曲线.结合提出的颤振识别方法,验证了动力学模型的准确性,可为实际加工中合理选择加工参数和颤振监测提供参考.
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