Study Of Acoustic Emission Source Localization Method On High-speed Train Bogie

As the high-speed trains and passenger transport indispensable tool, at first itssafety issues need to be protected. The bogie which is one of the most crucial parts ofthe high-speed train is served as trains carrying, pulling and other effects, so its safetyissues in particular need to get more attention.In the past, bogie testing is done under static which take much time and defectsoccur at runtime is difficult to be monitored. Therefore, in this paper for high-speedtrain bogies as the research object use the acoustic emission NDT methods for real-timemonitoring of the bogie. At the same time this paper introduce time-reversal into theacoustic emission, the time-reversal advantage is that acoustic emission signals canform the focus of the sound source, so making the acoustic emission signal is enhancedand more prominent.While making the time-reversal focusing of acoustic emission signals get enhanced,but due to noise ratio of the actual acoustic emission signals were relatively low andlead positioning not obvious. But in reality, the real loading time reversal signal is alsodifficult, even if signals can be load and be received, the signals will be overwhelmedby noise signal, and the structure of acoustic emission defect will change with theexternal conditions which will produce errors. Therefore, on the basis of thetime-reversal, this paper presents an improved method of acoustic emission defectspositioning from the analysis of signals and systems, which does not require realtime-reversal load, but can improve the acoustic emission signals signal to noise ratio,and get a time-reversal focusing effect.Firstly, the use of finite element analysis software to build steel flat model,simulate an acoustic emission signal in the model, using the time-reversal signal forpositioning verification. Afterwards building a high-speed train CRH2model bogieframe, using the improved time-reversal enhancement processes the data collected andusing MATLAB software to program positioning imaging. In order to verify theaccuracy of the actual positioning, the acoustic emission experiments used the samematerial and thickness of the steel sheet with the bogie frame, collected datas wereimaged with the improved time reversal enhanced method. The simulation andexperimental results show that the positioning method to detect the location of acousticemission sources have a good effect which can improve sound localization accuracy and reliability.