Acoustic Emission testing

Small motor rotor monitoring

Update time：2009-07-30 17:16　　　 Viewed：次

To action will occur between a rubbing rotor system caused by elastic strain and produce acoustic emission, which can make use of acoustic emission to identify and diagnose the characteristics of the rubbing fault, the first of the rubbing ae and rubbing vibration signal contrast study was conducted, and discussion based on the acoustic emission method of identification of rubbing don't unique superiority. Then, focuses on rubbing acoustic emission properties were studied, and by using the timefrequency analysis of wavelet scale spectrum is superior performance, the wavelet scale spectrum of rubbing the timefrequency characteristics of acoustic emission and propagation and dispersion characteristics are analyzed in detail. Spectrum analysis results show that the wavelet scale is very rich, suitable for rubbing acoustic emission frequency non-stationary and nonlinear multimodal wave, is a powerful method of modal acoustic emission analysis.

A multimodal potter of rotor system rubbing acoustic emission source signal in the process of complex waveguide transmission, due to the waveform modal wave speed difference and variation, the conventional correlation analysis algorithm is difficult to get the exact time and can not accurately beamformer. In order to solve this problem, the introduction of generalized crosscorrelation (generalized cross correlation, GCC) time delay estimation method to calculate the acoustic emission signal to time difference. Based on the modal acoustic emission and stochastic process theory based acoustic emission signal propagation model, to eliminate the noise influence on positioning, put forward based on the same fractional factor and different fractional factor of optimal linear fractional Fourier transform domain (Fourier) filtering of GCC time delay estimation; In view of the acoustic emission signals in the transmission wave variation caused by dispersion effect, result in unable to get the most relevant point problem, put forward the signal related product processing and related index of every block transform processing method of improvement. The experimental results show that the GCC time delay estimation of the spread of the acoustic emission signal in complex organizations can obtain a better correlation, has higher positioning accuracy.
(Editor：admin)

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