VIBROACOUSTIC TRANSMISSION BY DOUBLE-WALL ED CYLINDRICAL-SHELLS

A theoretical model is established to study the direct transmission of sound through a finite cylindrical double shell. Shells comply with D ONNELLS's equations and the theory include constantly spaced stiffener s in axial and circumferential directions. However this is limited in the case of large number of stiffeners. The acoustical excitation is a plane wave located in an infinite medium outside the shell. The two i nternal media are homogeneous. Absorption is taken into consideration by a complex wave number. The fluid structure coupling is exactly mode lised and mechanical links between shells are constant distributed sti ffness along circumferential lines. The solution of the equations is o btained by a modal method. Numerical results show the comparison betwe en structural linkage and air gap effects on the transmission of sound inside the inner cavity.