DYNCOMP’2015 2-4 June 2015, Arles (France) A MIXED “BIOT-SHELL” ANALYTICAL MODEL FOR THE CALCULATION OF SOUND TRANSMISSION THROUGH SANDWICH CYLINDERS WITH POROELASTIC CORES Julien Magniez 1* , Mohamed Ali Hamdi 1 , Jean-Daniel Chazot 1 and Bernard Troclet 2 1 Laboratoire Roberval UMR 7337 Universit´ e de Technologie de Compi` egne, CS 60319, 60203 Compi` egne cedex, FRANCE Email: julien.magniez@utc.fr, mohamed-ali.hamdi@utc.fr, jean-daniel.chazot@utc.fr 2 Airbus Defence & Space 51-61 Route de Verneuil, BP 3002, 78133 Les Mureaux Cedex, FRANCE Email: bernard.troclet@astrium.eads.net ABSTRACT In this work, the sound transmission through a sandwich cylinder with a poroelastic core is studied analytically. The cylinder is composed of two orthotropic skins, modeled with a shell theory, and a poroelastic core modeled with the full 3D Biot’s theory. Thus, a mixed “Biot- Shell” analytical model is presented in this paper. First, the motion of the sandwich cylinder obtained with this mixed “Biot-Shell” model is presented. Then, the model is used to calculate the sound transmission in the case of an excitation by an external oblique plane wave. A very good agreement is found when the results are compared to those obtained with a finite element model. Finally, some results are presented and the Transmission Loss (TL) is studied in different configurations. The main conclusion obtained from the results is that the poroelastic coating can significantly improve the TL of a cylindrical structure in mid- and high frequencies.