Vibroacoustic behavior of submerged stiffened composite plates excited by a turbulent boundary layer

Abstract

This paper presents a modal expansion technique-based method for predicting the vibroacoustic behavior of submerged stiffened composite plates under turbulent boundary layer (TBL) excitation. In the proposed method, the power spectral density of the Goody model is combined with the spatial correlation function in the Corcos form and then used to describe the turbulent fluctuating pressures. In addition, the transverse shear deformation of the stiffened composite plates under simply supported boundary conditions is considered. The contribution of the cross-modal coupling terms and the non-resonant modes to the mean square velocity and radiated sound power are analyzed. The results demonstrate that increasing the structural damping can be an efficient way to reduce the vibroacoustic response; the vibration level can be controlled by increasing the modulus ratio; lastly, the noise level can be reduced by increasing the areal density. The results of the stiffened composite plates show that there is almost no influence on the vibroacoustic response above 100 Hz regardless if the plate is reinforced streamwise or spanwise. However, increasing the length of the sub-panel between two stiffeners can be another effective way to reduce the TBL-induced noise.