Acoustic scattering by a finite elastic plate connecting two fluid-loaded parallel plates

A plane sound wave is incident upon two infinite parallel elastic plates which are connected by a finite elastic plate. All three plates support compressional and bending motion, and interact with any compressible fluid with which they are in contact. A method, which can be applied to obtain numerical results, for calculating the sound scattered by the connecting plate is presented. In the absence of fluid between the plates an approximate solution, valid for low frequencies and heavy fluid-loading on the upper plate, has been derived which exhibits good agreement with results obtained numerically.