Vibro-acoustic and sound transmission loss analysis of truncated conical shell subjected to incident sound wave

A combination of analytical method for shell vibration, boundary element method (BEM) for acoustic media of shell outer space, and finite element method (FEM) for shell inner space was used to study the vibro-acoustic behavior and extract sound transmission loss factor (STL) of a coupled vibro-acoustic system. The equation of motion of the shell is extracted based on the Donnell–Mushtari hypothesis and using Hamilton principles. The acoustic pressure on the outer and inner space is obtained using BEM on the defined nodes on the surface and these localized nodal pressures are converted to nodal concentrated forces. Finally, vibration of the coupled vibro-acoustic model is solved in frequency domain and vibration response of shell and acoustic pressure at any point in the media (outer, on the surface, and inner of shell) are obtained. Also, the STL of the shell is extracted based on the ratio of total acoustic energy received by the shell to that transferred to inner space.