A numerical approach to modelling the effect of a static pressure field on the frequency response of a clamped thin circular plate

A detailed understanding of the vibrational properties of submerged objects such as submarines is essential in order to minimise sound emission and optimise sonar performance. Complications arise when hollow structures are submerged in water producing loading on one side. Not only does the water dampen the resonances of the structure but also the increase in depth produces mechanical strain within the structure that changes the resonant frequencies. In previous work, the effect of hydrostatic pressure loading on one side of a rigidly clamped plate was investigated. The modal coupling between the water tank and the vibrating plate hindered the ability to observe the experimental dependence of the plate's frequency response on the applied hydrostatic pressure. In this paper some results are presented on the effect of static pressure loading produced by air on the plate, removing the complications introduced by fluid loading and modal coupling. The aim of this work is to accurately measure these effects experimentally and identify similarities and any interesting discrepancies with the numerical models used for prediction. The finite element package ABAQUS was used to model the frequency response of the plate subjected to a static pressure field produced by a finite air cavity.