In several industries (aeronautics, automobile, etc...), high performance acoustic insulating lightweight materials are often demanded for protecting people against extraneous airborne noise. This paper investigates a new solution that could match this requirement. The work concentrates on the diffuse field transmission loss of double wall barriers involving heterogeneous materials. The heterogeneous material is made up of porous materials in which macro solid pieces or air cavities are inserted. This material is then sandwiched between an elastic plate and a septum that are embedded in an infinite baffle. The numerical model is based on a finite element formulation for the different components. The coupling between the inclusions (solid or acoustic) and the porous patches is accounted for naturally through the use of appropriate Biot's formulations. This paper presents the theory behind the technique. Numerical results will be presented during the oral presentation.
展开▼
