Input Signal Recovering Using Regular Time Reversal And Inverse Filtering

摘要

The applicability of the time reversal method to Lamb wave propagation is investigated in order to recover the initial input signal in the long distance propagation of dispersive lamb waves . The simplicity of generation and sensing of the lamb wave make it suitable for structural health monitoring of thin plate-like structure because of their guided waves. Their dispersive properties frequently limit their practise in defect detection in which time arrival and amplitude dimension are not easy to determine. Time reversal processing can be applied to overcome these problems. Time reversal method using Lamb waves contains of three phases. A signal is produced into a plate structure through a transmitting transducer. Signal becomes dispersive though spreading across the plate. A different transducer acquires the transferred signal. The signal is inverted in time and re-emitted via the first transmitter two techniques are tested: Regular time reversal, inverse filtering and compared.