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摘要:
For wave propagation in dispersive media, the arrival time of acoustic emission signal to sensor depended on the setting of threshold voltage, which resulted in the inaccuracy of the acoustic emission location. Based on the wavelet transform and the theory of modal acoustic emission, a new method is proposed to improve the accuracy of acoustic emission source location. It is believed that the acoustic emission signal propagation in the structure has the characteristics of multi-mode and dispersion, and the acoustic emission source location should use the arrival time to sensors obtained from not only the same mode but also on the same frequency in the output signals. The wavelet transform was used to resolve the problem. By utilizing the time-frequency data of the wavelet, the frequency-dependent arrival time traveling was easily obtained; by numerical computation of the wave propagation in structure, the group velocity of the guided mode was also obtained, therefore the accuracy source location was realized. The acoustic emission source location experiments were conducted in a thin steel plate, it is demonstrated the technique is an effective tool for acoustic emission source location.
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来源 :
Chinese Journal of Scientific Instrument
ISSN: 0254-3087
年份: 2005
期: 5
卷: 26
页码: 482-485
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