Vibro-acoustic modelling of the box structural–acoustic coupling system

Abstract

The eigenmodes and vibro-acoustic responses for the box structural–acoustic coupling system composed of a box structure and an acoustic cavity are predicted using the energy principle and improved Fourier series. The improved Fourier series are adopted to describe the vibrations displacements of the box structure built up by six elastically coupled rectangular plates and the sound pressure in the cavity. The improved coupling energies suitable for the box structure having coordinate systems in different directions are presented to deal with the coupling problem of multi plates. The vibro-acoustic coupling energies in the establishment of the energy functions are composed of the work produced by the interaction between the acoustic space and the six elastically rectangular plates composing box structure. The eigenmodes of the coupled system are derived by employing the Rayleight Ritz method against the energy funcitions for the box structural–acoustic coupling system. The reliability of the presented model is verified by the good agreement of the eigenfrequencies and vibro-acoustic responses predicted by theoretical method and finite element method.

Keywords

• Box structure
• Acoustic cavity
• Eigenfrequencies
• Vibro-acoustic responses