The vibroacoustic response of a cylindrical shell structure with viscoelastic and poroelastic materials

The study of the vibroacoustic behavior of an aircraft fuselage requires th e generation of very large and complex finite element models (FEM) and, fur thermore, the numerical results are often very difficult to interpret and t o validate. On the other hand, the study of the vibroacoustic behavior of a simple cylindrical shell structure should allow us to validate the results obtained from these simple numerical models and to study the efficiency of different analysis tools and design solutions for vibration and noise redu ction, such as the addition of visco-elastic and porous materials. In order to achieve these objectives, two cylindrical shell structures were studied . The first model was used for the study of the dynamic behavior of the str ucture with and without visco-elastic material. The second model was used f or the study of the vibroacoustic behavior with and without porous material . Results show a good correlation between experimental measurements and num erical predictions. Efficiency of the two proposed solutions was evaluated and, finally, it has been demonstrated that the effect of the modal truncat ion of the cavity modal basis is critical for the convergence of the predic ted pressure field and that a good understanding of coupling phenomena betw een structural and acoustic modes is necessary. (C) 1999 Published by Elsev ier Science Ltd. All rights reserved.