Abstract

This diploma-thesis covers the derivation of the equations which describe the propagation of forced bending waves in thin plates and the analytical methods which can be used to calculate the sound radiation of those bending waves from the plate into the surrounding air. In particular the main focus of the work lies on the derivation of an analytical description of the sound radiation from the „Manger Sound Transducer”. The radiating surface of this transducer is not a rigid piston but a flat, circular, damped, pliable plate.

To calculate the movement of the plate we derive the governing equation of the Kirchhoff plate. For the calculation of the sound radiation of the plate, which acts as a plane radiator, we do not use Rayleigh’s method of decomposition into monopole sources, but we decompose the movement of the plate into plane waves using Fourier-transformation (wavenumber spectrum). The overall solution is obtained by superposition of the contributions of the separate waves. Because of the axial symmetry of the problem we use a Hankel-transformation instead of a two-dimensional Fourier-transformation. By assuming the plate to be infinite one can use the waveimpedance and the radiation impedance of the infinite plate to work entirely in the spectral domain.

Full Text and additional Material

You can download the full version of the diploma thesis here.

Notice

As in 2011 the Acoustics and Audio Group moved from the Institute of Broadband Communications (IBK) to the Signal Processing and Speech Communications Laboratory (SPSC), the puplishing location of this thesis also was transfered from the IBK to the SPSC-website.