基于小波变换与统计分析的转子碰摩声发射特性研究

Acoustic emission characteristics of rotor rubbing based on wavelet transform and statistical analysis

为解决转子碰摩损伤声发射信号分类及解释难题,应用PCI-2声发射系统和WS-ZHT1型多功能转子实验台组成转子碰摩声发射检测系统,采集转子局部碰摩声发射信号,通过理论分析声发射信号特征和小波基函数性质,dB8小波适合提取声发射信号特征;碰摩产生大量声发射信号,大量声发射信号的统计特性蕴涵较多碰摩信息。对不同转速条件下不同检测位置碰摩声发射信号的统计分析表明,声发射信号的功率谱密度集中在100～400 kHz。声发射信号平均幅值、平均能量可作为区分转子碰摩程度特征参数;功率谱主频可作为区分碰摩相对位置特征参数,结论与碰摩类型无关。

To resolve the difficulty in processing,interpreting and classifying AE(acoustic emission) data,a rotor rubbing detecting system was designed,which is composed of PCI-2 AE system and WS-ZHT1 multi-function rotor test rig.The AE signal generated by rotor rubbing was sampled by the system on the rig.According to the nature of AE signal and the performance of wavelet function,the dB8 wavelet function was taken for extracting the AE signal character.The AE signals created by rotor rubbing was then analysed statisically under different rotor speeds.The spectrum of AE is in the frequency range of 100 ~ 400 kHz.The average amplitude and energy of AE were used to identify the extents of rotor failure and the main part of power spectrum was used to instruct the location of Rotor rubbing.The conclusion is not affected by the style of rotor rubbing.