Numerical prediction of the sound transmission loss of double panel configurations with acoustic structured and poroelastic materials

Abstract

The sound transmission loss of multilayer system assemblies made of Noise Control Treatments comprising metamaterials and poroelastic materials, sandwiched between two structural panels is of utmost importance in aerospace, automotive, building and several other engineering applications. The integration of acoustic metamaterials in these systems introduces a number of challenges at the level of numerical simulation in order to predict their acoustic and structural behavior. This paper presents a methodology for the numerical simulation of the sound transmission loss of structural configurations comprising acoustic metamaterials embedded in a glass wools layer, sandwiched between two elastic panels. The metamaterial is designed as a parallel assembly of four sub-metamaterials. Each of these sub-metamaterials is also a series assembly of a periodic unit cell having a neck + cavity + neck type configuration. The four sub-metamaterials are designed so that their first resonance frequencies are grouped together in order to improve the sound transmission loss at the first two natural frequencies of the double panel. The COMSOL Multiphysics finite element method solver is used. The normal incidence and diffuse field sound transmission loss numerical results are presented and discussed in comparison with results from literature for validation.