摘要
We present an analytical investigation for a baseline-free imaging of a defect in plate-like structures using the time-reversal of Lamb waves.We first consider the flexural wave(A0 mode)propagation in a plate containing a defect,and reception and time reversal process of the output signal at the receiver.The received output signal is then composed of two parts:a directly propagated wave and a scattered wave from the defect.The time reversal of these waves recovers the original input signal,and produces two additional sidebands that contain the time-of-flight information on the defect location.One of the side-band signals is then extracted as a pure defect signal.A defect localization image is then constructed from a beamforming technique based on the time-frequency analysis of the side band signal for each transducer pair in a network of sensors.The simulation results show that the proposed scheme enables the accurate,baseline-free imaging of a defect.
基金
by Basic Science Research Programn(2010-0013901)
by the Nuclear R&D program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology.
