Based upon the vibratory equation and sound radiation impedance of a cylindrical shell, the sound field distribution of a finite cylindrical shell simply-supported at two infinite rigid cylindrical shells were obtained with considering the structural loss. The sound directivity patterns of a finite cylindrical shell with two end plates were computed by using Finite Element Method and Boundary Element Method (FEM/BEM) and the results were compared with the analytical results. It has been shown that the sound radiation power of the cylindrical shell decreases and the radiation efficiency increases with increasing of structural damping loss factors.When the frequency of the driving force is low, the sound field shapes “∞”directivity pattern. When the frequency of the driving force grows higher the sound directivity pattern becomes complex due to superposition of axial modes and circumferential modes. Only when the radiation of the end plates is much weaker than the cylindrical shell the analytical results of the shell simply-supported at two infinite rigid cylindrical shells can be utilized to illustrate the sound radiation by a finite cylindrical shell with two end plates. Computation of sound radiation of a finite simply-supported cylindrical shell requires considering the structural loss.

cylindrical shell; structural loss; sound radiation impedance; acoustic field distribution