The time reversal method has been widely used in non-destructive damage detection, underwater acoustic exploring, and medical monitoring. The proposed method utilizes the acoustic wave characteristics of having different propagating paths in an inhomogeneous media, such as a cracked plate. Based on this feature, the position of a crack in a plate can be found by the time reversal method, which can selectively focuses the reemitting waves on the crack location to be detected. However, because of geometrical effects, which may result in the defocusing and distortion of the waveform and may cause the socalled the multi-path problem on wave propagation, the array signal processing method is then applied to solve the multi-path problem. In this study, a method, consisting of the array signal processing method and the self-focusing method, is proposed to deal with the multi-path effects and to find the exact crack location in a plate. In the method, the delayed time caused by different wave propagating paths in a cracked plate, is utilized to reconstruct a scattered path pointing to the crack location. In the present investigation, the finite element analysis is used to simulate the surface wave propagation and to verify the validity of the proposed method in detecting a plate crack. Time Reversal Method, Scattered Path, Delay-and-Sum Beamforming Method, Array Signal Processing.
|頁（從 - 到）||181-194|
|期刊||Journal of Taiwan Society of Naval Architects and Marine Engineers|
|出版狀態||Published - 2011 八月|
All Science Journal Classification (ASJC) codes
- Ocean Engineering
- Mechanical Engineering