Experimental evidence of absolute band gaps in phononic crystal pipes
Résumé
The vibration filtering properties of a phononic crystal pipe whose unit cell consists of two segments of different material and cross-section are studied numerically and experimentally. Such an architected bi-material pipe leads to an alignment of the dispersion branches in the same frequency ranges for all types of waves (flexural, longitudinal, torsional), leading to an absolute band gap. Each motion is studied by a 1D model in which the propagation of Floquet-Bloch waves in lossy media are considered. The numerical optimization is based on the simplex algorithm and aims to control both the central frequency and the band width of the absolute band gap on a selected target. Experimental characterization of a demonstrator confirms the filtering effects due to partial and absolute band gaps even in the presence of quite high structural damping.
Origine : Fichiers produits par l'(les) auteur(s)
Loading...