Imaging laminar damage in plates using lamb wave beamforming

This paper presents the application of Lamb waves to detect and locate laminar damages using a beam forming imaging methodology. Beam forming is using a network of transducers that are used to sequentially scan the structure before and after the presence of damage by transmitting and receiving guided wave pulses. An image of the damage is reconstructed by analysing the cross correlation of the scatter signal with the excitation pulse and enables the detection and location of potential damage areas. The results of simulation and experimental studies show that the method enables the reliable detection of structural damages with locating inaccuracies in the order of a few millimeters within inspection areas of 300 x 300 mm(2) using a transducer network of only four transducer elements.