Attenuation of flexural waves on a fluid‐loaded plate with many identical supports

Abstract

A power‐balance analysis is carried out for the response and sound radiation of a homogeneous fluid‐loaded wave‐bearing structure with many identical supports, when the structure is driven at one support point. A single second‐order difference equation is found for the response, subject to the hypothesis that the energy flux from any support to its neighbors involves only one wave type. Results have been calculated for a thin steel plate with inertial supports and water on one side, for frequencies less than the critical frequency. A marked difference is found between the levels of energy flux away from and toward the source in the same bay (i.e., reverberation is not strong). The attenuation rate due solely to sound radiation is significant (1–2 dB per support) except at low frequencies. Internal dissipation is enhanced by the reverberation, relative to dissipation in a plate without supports.