机械密封碰摩声发射信号的特征提取方法研究

Study on Feature Extraction Method of Rub-Impact AE Signals of Mechanical Seals

提出利用声发射(Acoustic Emission,AE)技术监测机械密封动静环的碰摩状态。通过分析典型碰摩AE信号的特点,提出利用小波尺度谱和功率谱相结合的方法表征机械密封端面碰摩AE信号的特征信息,小波尺度谱能够直观地描述AE信号中各个脉冲的数目、到达时间、能量大小、在时频面上的分布及频率组成,为判断碰摩的类型、严重程度及发生时间提供准确信息,AE信号的功率谱图能够给出信号能量的具体值。在仿真和实验研究中该方法被有效运用于判别机械密封端面的偶然性碰摩、周期性碰摩和连续性碰摩。

Rub-impacts between the rotating ring and stator ring of mechanical seals appear always in operations, which may be danger to the mechanical seals. So the acoustic emission （AE） technique is put forward to monitor the rub-impacts. By analyzing the typical characteristics of AE signalz of rub -impacts, the method combining of wavelet scalogram and power spectrum is found useful, and can used to attribute the feature information implicated in rub-impact AE signals between the two suoraves of mechanical seal. The wavelet scalogrum can represent many characteristics of all the impulses implicated in the AE signals, including of the number, arrival time, energy, distribution in the time-frequency planc, components of the frequency, which can provide accurate information to distinguish the style, severity and time of the rub-impacts. The power spectrums of AE signals can provide the specific values of signal energy. Both simulations and experimental research prove that the method is effective, and is used successfully to distinguish the typical features of rub-impacts of mechanical seals, such as accidental rub-impact, periodic rub-impact and continuous rub-impact.