Radiation efficiency of a composite cylindrical shell

The radiation efficiency of a composite cylindrical shell is estimated from the averaged modal radiation efficiencies based on eigenvalue solutions. Only acoustically fast modes are considered in the analysis as acoustically slow modes are found to have minor influence in the averaged modal radiation efficiency. The shear deformation and the rotary inertia of the shell are also included in the analysis for high frequency application. The effects of each extension stiffness terms A11 to A66 and bending stiffness terms D11 to D66 on the radiation efficiency are studied by varying each stiffness terms independently. Statistical estimation of the radiation efficiency is carried out to account for the geometrical and material parameters variations as per SEA framework. The effects of length, radius, thickness and the laminate layer sequence on the radiation efficiency are studied for different symmetrically laminated shells. Experiments are carried out by exciting composite shells of two different sizes in a reverberation chamber to validate the theoretical prediction of radiation efficiency. Good agreement between the theoretical estimations and experimental values is observed.