Time reversal and cross-correlation analysis for damage detection in plates using Lamb waves

The paper mainly presents the time reversal theory and cross-correlation algorithm to focalize the Lamb wave scattered signals caused by the damage. Time reversal theory has been developed to improve the detection ability of Lamb waves. Cross-correlation of scattered signal envelope with excitation signal envelope is used for damage imaging. Experiments are carried out on an aluminium plate using a transducer network consisting of four identical piezoelectric transducers as actuators and as well sensors for excitation and measurement of Lamb waves. The results show that this method is able to accurately predict damage location and provides an estimation of the possible area even for damage close to one of the transducers or even slightly outside the transducer network.