TRANSMISSION ACOUSTIQUE PAR DES STRUCTURES SANDWICHS DE TYPE ARIANE V : PRISE EN COMPTE DES EFFETS D'ÉCRASEMENT ET DE CISAILLEMENT TRANSVERSE

Abstract
The main goal of vibroacoustic studies on the Ariane V launch vehicle, multilayered orthotropic cylindrical structure is to achieve low magnitude internal acoustic environment. This can be do, |1| - |2|, without increasing the mass per unit area, by increasing the core thickness of the three layered basic structure. But this reduce the transverse structure stiffness ; so it is of first interest and importance to examine if the classical two dimensionnal (2D) hypothesis is a good approximation ; or if the differencies on the transmission loss (T.L) between the cases 2D and 3D (three-dimensionnal theorie including transverse thickness deformation) are very noticeable. Thus, we develop a new vibroacoustical analytical model including for each layer a 3D field displacement ; and we present some results for the T.L 2D - 3D comparison for a three layered Ariane V configuration.