On predicting the response of acoustically-excited doubly curved sandwich panels

This paper presents a recent programme of research, which has concentrated on the measurement and prediction of the dynamic response of doubly curved composite honeycomb sandwich panels to high intensity, random acoustic excitation. Four panels with varying radii of curvature were tested in a progressive wave tube (PWT) facility at overall sound pressure levels up to 164 dB (re 2 x 10(-5) Pa). Several methods are presented to predict the dynamic response of the panels to random acoustic excitation. The first of these was the single-degree-of-freedom (SDOF) approximation method, where different assumptions with regard to the spatial characteristics of the pressure loading are made. Finite element analysis (FEA) was also used to predict the response, where the pressure loading was assumed to consist of a series of travelling waves at grazing incidence to the structure. The results presented for both the SDOF approximation method and the FEA method show good agreement between predicted and measured strain values, which are also presented.