Acoustic radiation and frequency response of higher-order shear deformable multilayered composite doubly curved shell panel – An experimental validation

Abstract

In this article, the acoustic radiation responses of doubly curved laminated composite shell panels subjected to harmonic excitation are investigated numerically in the framework of the higher-order shear deformation theory. A general mathematical model for the vibrating curved panel has been developed and the cylindrical, spherical, elliptical and hyperboloid shell panel geometries resting on an infinite rigid baffle are considered for analysis. The desired response is computed using an in-house code developed in MATLAB. Firstly, the natural frequencies of the vibrating shell panel are obtained using the present model and validated with data available in the literature with experimental test results. A coupled finite element/boundary element formulation is then used to obtain the acoustic response of the structure. The mean square velocity, radiation efficiency and the sound power radiated are chosen as the acoustic response indicators. The effect of different support conditions, lamination schemes, aspect ratio and geometry of the vibrating doubly curved shell panel on the acoustic radiation behaviour is investigated and discussed in detail. It is observed that the support conditions and the lamination scheme greatly influence the acoustic radiation from the panels. On the other hand, the radiation pattern is quite similar for different geometries with a substantial distinction for flat plate.