Lamb wave propagation modelling for damage detection: II. Damage monitoring strategy

Wave propagation modelling is important for reliable damage detection based on Lamb waves. A number of different numerical computational techniques have been developed for wave propagation studies. The local interaction simulation approach, used for modelling sharp interfaces and discontinuities in complex media, has been applied effectively for numerical simulations of elastic wave interaction with structural damage. The paper builds upon this experience and reports numerical investigations of Lamb wave propagation modelling for damage detection in metallic structures. The ultimate objective of these investigations is to demonstrate that numerical simulations can significantly ease the monitoring strategy used for damage detection with Lamb waves. The interaction of fundamental Lamb wave modes with a rectangular damage slot in an aluminium plate is investigated as an example. The second part of the wave propagation studies focuses on the monitoring strategy for damage detection. The effect of sensor position on the amplitude and time of flight of Lamb waves is investigated and discussed for various severities of damage. The results are validated experimentally.