Progress in the fields of vibroacoustics and metamaterials are largely driven by our ability to predict and understand how waves propagate and scatter in complex media. Lamb waves’ cut-on and conversions alone, have been the subject of countless investigations in composite laminates. The generation and dispersion of ‘ring modes’ have received a lot of attention for obvious NDT purposes in pipes, but unfortunately very seldom studies have been conducted in composites. These waves can be seen as a particular type of guided resonance, which correspond to the out-of-plane modes of a waveguide’s finite cross-section propagating along its main direction. Despite their computational cost, numerical methods have shed new lights on the interesting coupling and conversion effects affecting the propagation of guided waves in sandwich or multi-layer core topology structures. During this seminar an insight on guided resonance coupling effects occurring in sandwich structures will be proposed. After reviewing recent progress on Bloch-modelling framework and their applications to composites, a variety of wave scattering features will be discussed. The specific case of guided resonances in composites will be analyzed numerically and experimentally.

Droz et al. (2019). Generation of long-range, near-cut-on guided resonances in composite panels. Journal of Applied Physics, 125(17), 175109. Lien RGate : https://www.researchgate.net/public...