Lamb wave methods

Kessler et al [2001] in their paper on ‘Structural health monitoring in composite materials using Lamb Wave methods’ have dealt with Lamb wave method for in-situ damage detection of composite materials. Experimental results are presented for the application of Lamb wave techniques to quasi-isotropic graphite /epoxy thin coupons and sandwich beams containing representative damage modes, including delamination, transverse ply cracks and through-holes. Optimization experiments provided a procedure capable of easily and accurately determining the presence of damage by monitoring the transmitted waves with PZT sensors. Lamb wave techniques have been proven to provide more information about damage type, severity and location than previously tested methods, and may prove suitable for structural health monitoring applications since they travel long distances and can be applied with conformable piezoelectric actuators and sensors that require little power.