Vibro-acoustic characteristics of shear deformable stiffened laminated panels in mean flow

Abstract

A theoretical model is developed to investigate vibro-acoustic characteristics of shear deformable periodic stiffened laminated composite panels in mean flow, based on the first-order shear deformation theory (FSDT). The convected wave equation and boundary condition are used to account for the exact coupling effect between mean flow and laminated panel. Stiffeners interact with the laminated panel through both the normal line forces and torsional moments. Analytic formulations for the transverse displacement spectra and sound pressure level (SPL) are yielded by employing the Fourier wavenumber transform and the stationary phase method. The model is validated by comparing with existing public data. Excellent agreement is obtained. Numerical results show that the effects of shear deformation and torsional motion of the stiffeners cannot be ignored in high frequency range. SPL can be reduced by increasing the speed of mean flow; it is possible to avoid SPL peaks by altering the thickness and stiffener spacing.