Modelling of Lamb wave interaction with open and closed fatigue cracks for damage detection

Abstract

Lamb waves are the most widely used guided ultrasonic waves for structural damage detection. Lamb wave propagation in complex structures is very complicated due to multiple reflections and mode conversion at geometrical and material features. Numerical simulations can significantly ease wave propagation analysis for damage detection. The local interaction simulation approach is used for Lamb wave interaction with fatigues cracks in an aluminium plate. The results, investigated for various crack lengths, are validated experimentally. The study shows that Lamb wave amplitude and arrival time are different for fully open and closed fatigue cracks. As a result damage detection sensitivity could be affected.