Vibration and sound radiation of viscoelastically supported Mindlin plates

Abstract

Models based on the Mindlin plate theory were developed and used to investigate the vibro-acoustic characteristics of sandwich panels with viscoelastic supports. The Rayleigh-Ritz method was used to predict the vibration response of the plate subjected to distributed random forces with imposed spectral characteristics. Sound radiation efficiency was calculated for each mode, which allowed the radiated sound power spectra to be determined. Timoshenko beam functions were used as the trial functions. This approach ensured a fast convergence rate, which is advantageous for vibration and sound radiation analysis of high-order modes. The optimal support properties for minimum vibration amplitude were determined. Vibration energy dissipation at the edges was found, as expected, to regulate the vibration amplitude. The effects of the plate mechanical properties on the vibration amplitude and sound radiation were investigated. Sound was found to be predominantly radiated by bending deformation of the face materials at low frequencies, and shear deformations of the honeycomb core at higher frequencies.