Structural damage detection using combined finite-element and model Lamb wave propagation parameters

This article presents a combined finite-element and model Lamb wave propagation parameters method for structural health monitoring. Modal analysis allows identifying the mode conversions induced by the defects. A simulation combining a planar, lossless finite-element analysis with Lamb wave propagation parameter is proposed. This analysis is performed on two aluminium bars in both undamaged and damaged states, where the two damaged states are: (a) one having a circular hole and (b) the other having a cut partway through the bar, perpendicular to the long axis of the bar. The Lamb wave propagation parameters are calibrated by using the ultrasonic pulse generator test set-up. The natural frequencies for the theoretical, finite element and experimental results are compared, and close agreement is found between the frequencies obtained experimentally and computationally.