Vibration and Acoustic Radiation Analysis of Stepped Circular Cylindrical Shells by Using a Semi-Analytical Method

In this paper, the vibration and acoustic radiation characteristics of stepped circular cylindrical shells (SCCS) immersed in infinite fluid medium is presented. Based on the Flugge’s thin shell theory, the theoretical model for vibration analysis of SCCS is established, whereas sound radiation analysis is carried out by solving the Kirchhoff–Helmholtz integral equation. The Chebyshev polynomials is set as shape function for vibration and acoustic radiation analysis of the SCCS, all displacements are represented by a separate variable in the meridional and circumferential directions, with Chebyshev polynomials and Fourier series. For discretizing of acoustic boundary, a set of Chebyshev collocation points and spectral boundary element are introduced, and for solving the non-uniqueness problem in acoustic radiation analysis, the CHIEF method is applied. Through comparison studies with the results of previous literature and the coupled finite element method/boundary element method (FEM/BEM), the accuracy, convergence and reliability of the proposed method are verified. Finally, the effects of geometry, boundary conditions, fluid medium, material properties and type of applied force on the acoustic radiation characteristics caused by vibration of SCCS are investigated by several numerical examples.