School of Transportation Science and Engineering, Beihang University, Beijing 100191, PR China; Airworthiness Technologies Research Center, Beihang University, Beijing 100191, PR China.
Ultrasonics. 2014 Jan;54(1):318-29. doi: 10.1016/j.ultras.2013.04.017. Epub 2013 May 3.
This paper attempts to introduce an improved acoustic emission (AE) beamforming method to localize rotor-stator rubbing fault in rotating machinery. To investigate the propagation characteristics of acoustic emission signals in casing shell plate of rotating machinery, the plate wave theory is used in a thin plate. A simulation is conducted and its result shows the localization accuracy of beamforming depends on multi-mode, dispersion, velocity and array dimension. In order to reduce the effect of propagation characteristics on the source localization, an AE signal pre-process method is introduced by combining plate wave theory and wavelet packet transform. And the revised localization velocity to reduce effect of array size is presented. The accuracy of rubbing localization based on beamforming and the improved method of present paper are compared by the rubbing test carried on a test table of rotating machinery. The results indicate that the improved method can localize rub fault effectively.
本文试图介绍一种改进的声发射（AE）波束形成方法，以定位旋转机械中的转子-定子摩擦故障。为了研究旋转机械机壳壳板中声发射信号的传播特性，薄板中采用板波理论。进行了仿真，结果表明波束形成的定位精度取决于多模态、频散、速度和阵列尺寸。为了降低传播特性对源定位的影响，提出了一种结合板波理论和小波包变换的 AE 信号预处理方法。并提出了修正的定位速度以减小阵列尺寸的影响。通过在旋转机械试验台上进行的摩擦试验，比较了基于波束形成的摩擦定位的准确性和本文提出的改进方法。结果表明，改进的方法可以有效地定位摩擦故障。
