Acoustic transmission loss in Hilbert fractal metamaterials
Résumé
Acoustic metamaterials are increasingly being considered as a
viable technology for sound insulation. Fractal patterns constitute
a potentially groundbreaking architecture for acoustic
metamaterials. We describe in this work the behaviour of the
transmission loss of Hilbert fractal metamaterials used for sound
control purposes. The transmission loss of 3D printed metamaterials
with Hilbert fractal patterns related to configurations from the
zeroth to the fourth order is investigated here using impedance
tube tests and Finite Element models. We evaluate, in particular,
the impact of the equivalent porosity and the relative size of the
cavity of the fractal pattern versus the overall dimensions of the
metamaterial unit. We also provide an analytical formulation that
relates the acoustic cavity resonances in the fractal patterns and
the frequencies associated with the maxima of the transmission
losses, providing opportunities to tune the sound insulation
properties through control of the fractal architecture.
Domaines
Mécanique [physics]
Origine : Fichiers produits par l'(les) auteur(s)