The Study On Acoustic Emission Characteristics Of Axle Crack Based On Wavelet Packet Energy Entropy And Wavelet Entropy

With the development of modern high-speed railway,the train is running faster and faster,and more and more people pay attention to the safety of train operation.As an important part of train axle,its importance is self-evident,to train security relations,so the axle of the real-time monitoring and diagnosis,to avoid the axles in the running process of the vehicle damage has become an arduous and important task.Therefore,we need to carry on the fault diagnosis to the axle through various methods,find out the fault problem and deal with it in time,so it has very important practical significance to the fault diagnosis of the acoustic emission signal.Firstly,this paper introduces the acoustic emission detection technology and the traditional fault diagnosis technology,as well as the research status at home and abroad.In the first part of this paper,the application of wavelet packet energy entropy method in the fault diagnosis of the acoustic emission signal of axle is discussed.Combined with the advantages of wavelet packet analysis and energy entropy analysis,a wavelet packet energy entropy based method for fault diagnosis.The acoustic emission signal is decomposed into eight bands,spectral analysis that fault feature mainly the first 4 bands by wavelet packet energy,then calculate the 4 band wavelet packet energy entropy to evaluate the evaluation parameters;then the simulation analysis is carried out by MATLAB software,the transmission signal into a signal the acoustic emission signal and the crack normal sound,and set the sliding window on the integration of signal analysis,then analysis chart entropy change,find the fault characteristics,proved that the wavelet packet energy entropy method can effectively extract the acoustic emission signal of axle fault signs.The second part of this paper based on wavelet entropy theory,application selection spectrum entropy,wavelet entropy,wavelet energy spectrum entropy and wavelet packet energy entropy and Shannon entropy five specific sub band energy method in fault diagnosis of acoustic emission signal.To collect the axle acoustic emission signal as an example,after the crack acoustic emission signal and the normal AE signal time-frequency analysis,wavelet decomposition and wavelet packet decomposition,the value of feature extraction.And the experimental data were analyzed by MATLAB software,the simulation of sliding window entropy in the form of curves reflected in the chart,more convenient and intuitive compared to fault feature extraction of acoustic spectrum difference analysis,entropy method and specific sub-band energy entropy method can better signal fault feature.