Propagation of Lamb waves in anisotropic and absorbing plates: Theoretical derivation and experiments

The aim of this work is to gain a better understanding of the propagation of Lamb waves in anisotropic and absorbing plates. A study of the energy velocities and attenuations of Lamb waves in such media is presented here. In the first part, propagation in principal directions has been studied. In order to measure the attenuation of guided modes, an experimental set-up has been developed using a laser sensor. Predictions and experimental results for a unidirectional Glass Epoxy plate are described and discussed. In the second part of this work, the non-principal direction problem is approached. Preliminary results of the steering angle phenomena for guided modes are obtained and discussed.