Determination of the Group Velocity and Source Location of Dispersive Plate Waves using Wavelet Transform

Wavelet 변환을 이용한 분산성 판파의 군속도와 음원 위치 결정

Jang, Yeong-Su;Jeong, Hyeon-Jo

  • Published : 2000.04.01


The plate waves propagating in thin plates have dispersive nature showing the dependence of velocities on the frequency. Wavelet transform (WT) using Gabor function can be used to analyze the dispersive waves in the time-frequency domain, and then to find the arrival time of the waves propagating in the plate. Plate waves in the aluminum plate of 3 mm thickness were identified and generated by pencil lead breaks and the lowest order symmetric ($S_o$) and antisymmetric ($A_o$) modes were analyzed by the WT method. The measured group velocities agreed very well with theoretical predictions in the frequency range of 50-400 kHz. The pencil breaks were also used to simulate acoustic emission sources in the plate, and the source location algorithm using the wavelet transform of dispersive plate waves was found to give accurate results.


Wavelet Transform;Plate Wave;Dispersion;Fourier Transform;Time-Frequency Analysis;Group Velocity;Source Location


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