The role of the resonance modes in the response of a fluid-loaded structure

This paper is concerned with problems of fluid/structure interaction. The a im is to show how the resonance modes can be used to describe the response of a fluid-loaded structure (displacement of the structure and sound pressu re in the fluid) for any kind of excitation (periodic, randomly dependent o n time and space, or transient). First, the expression of the response of t he system in terms of resonance modes is recalled. To compute the resonance modes, it is necessary to solve a system of equations in the harmonic regi me. Several numerical methods are considered and a comparison of their resp ective efficiency is presented. Finally, two examples of applications are s tudied in detail. Namely, a thin plate excited by a turbulent wall pressure and a thin shell excited by a transient acoustic signal. For this last exa mple, some experimental data are compared with numerical results. (C) 2001 Academic Press.