Lamb Waves for Damage Localisation in Panels

Abstract: In this study, Lamb wave propagation phenomena have been used to localise discontinuities in aluminium and composite panels. For that purpose, piezoelectric transducers have been used to excite and register Lamb waves in the panels. Excited waves that propagate and reflect from the panel edges and discontinuities were registered by piezoelectric sensors as voltage changes in time. Three different experiments have been conducted to investigate the wave propagation phenomena. In the first experiment, the attenuation and dispersion of Lamb waves in the aluminium panel has been studied. The second experiment has been oriented to localise an additional mass attached to the same panel. A dedicated signal‐processing algorithm has been developed to aid the localisation procedure that allowed to extract relevant features of the discontinuity. The algorithm has been tested on signals from the panel with and without the additional mass. The results obtained have been compared to find the position of the discontinuity. The third experiment concerned a more realistic damage scenario when piezoelectric transducers have been arranged as a clock‐like array to find a crack in a composite panel.