A Technique for the Modal Analysis of Sound-Structure Interaction Problems

Abstract In most sound-structure interaction problems involving the fluid in a cavity and the flexible wall of the cavity, the governing equations of motion are coupled through velocity terms. The coupling matrix for such systems is skew-symmetric and hence requires complex eigenvalue extraction routines to find the coupled natural frequencies. Instead, in this paper, we form an equivalent set of equations which can be solved for the natural frequencies using real eigenvalue extraction routines. Furthermore, we show how to synthesize the modal properties of the interacting system from those of the non-interacting fluid and structural systems. The results obtained using our method compare well with the experimental data of previous researchers.