Font Size: 

The main advantage offered by composite structures used in the aeronautical field is the high strength to weight ratio. Usually it becomes less important when we analyse its behaviour into the acoustic field, when we analyse the interior noise levels. The insertion of sound proofing materials - porous foams - inside these structural panels contributes to considerably diminish the sound pressure levels in the aircraft’s interior, allowing to reach the maximum levels imposed. With the target of improving these contributions, actually different combinations in order to minimize the assembly time and flow, material and fabrication costs, interiors weight and internal noise level are proposed. The choice of an appropriate multilayer configuration must also consider the processing technologies and production methodologies that integrate the linings and sound proofing panels in a single fabrication cycle. The searching for complex combination that could satisfy the structural aspects as well as the acoustics ones is realized by computational numeric predictions. In this paper we present the numeric predictions for the transmission loss of different multilayer material panels used in the aeronautic industry as well as the results obtained from the new configurations proposed. The transmission loss predictions are validated by comparisons with experimental measurements. As result we expose a brief comparison between the advantages and disadvantages of the model in use and the models we propose.