Evidence of acoustic insulation performances of metaporoelastic layers
Résumé
A low mass and space requirement structure exhibiting high sound insulation over a wide frequency range is a major industrial concern, especially in the transport and building sectors. Metaporoelastic layer is promising structured interface to solve this issue. It consists of a poroelastic layer with periodic resonant inclusions embedded in [1]. The acoustic properties of such metaporoelastic interfaces are greatly enhanced in the low frequency range compared to those of the single poroelastic layer. The studied interface is a metaporoelastic layer covered with an impermeable film on one side and by an elastic plate on the other side. Experimental evidence of a huge improvement in the transmission loss of this structure compared to the same structure in the absence of resonant inclusion is reported. This work aims at understanding the physical phenomena at the origin of this improvement. A finite element model under Comsol Multiphysics is proposed to obtain the transmission loss of such kind of systems and validated against Multiple Scattering results. The acoustic behavior of the structure is investigated via a systemic study of configuration of increasing complexity: from an infinite poroelastic layer to a coated metaporoelastic layer backed by the elastic plate. The physical contributions of each element to the extraordinary transmission loss are thus identified. [1] T. Weisser, J.-P. Groby, O. Dazel, F. Gautier, E. Deckers, S. Futatsugi and L. Monteiro, Acoustic behavior of a rigidly backed poroelastic layer with periodic resonant inclusions by a multiple scattering approach, J. Acoust. Soc. Am., 139: 617-630, 2016.