Vibroacoustic response of stiffened thin plates to incident sound

Abstract

A model was developed and applied for predicting the vibroacoustic response of stiffened plates excited by different incident sound fields. A relationship between the Joint Acceptance Function (JAF) and the modal radiation efficiency is derived. This allows a direct calculation for both the vibration response and the sound transmission loss (TL) in the presence of a diffuse field whilst accounting for full vibroacoustic coupling. The response for different structural configurations, plane versus diffuse acoustic excitation and modelling approximations are highlighted, so presenting a systematic quantification of the factors influencing the vibroacoustic response. It is found that vibroacoustic coupling is enhanced by the presence of stiffeners, with the effects for different types of acoustic excitation and the contribution from the modal cross terms being most significant for the TL results.A coupled FE-BE numerical model of stiffened plate and other empirical formulae for unstiffened plate are subsequently used for the validation and verification of the proposed model. The results show that the computational cost of simulation can be significantly reduced with a small loss of accuracy when using the proposed model in comparison to the fully coupled FE-BE numerical model.