ASA 127th Meeting M.I.T. 1994 June 6-10

2pSA11. Analytical solutions for axisymmetric radiation and scattering from a spherical shell with internal circular plates.

Murugan Subramaniam

Jeffrey K. Bennighof

Dept. of Aerosp. Eng. and Eng. Mech., Univ. of Texas at Austin, Austin, TX 78712-1085

Analytical solutions for problems of radiation and scattering from a spherical thin shell containing one or more circular thin plates are presented. The geometry of both the structure and the loading is axisymmetric. These solutions can be used to evaluate computational methods for radiation and scattering from finite three-dimensional structures having internal complexity. In this case the internal complexity is associated with the internal plates, which are represented in terms of their axisymmetric modes of vibration. The motion of the spherical shell is represented in terms of spherical harmonics. The analytical solutions are verified with numerical results obtained using an adaptive multi-level substructuring approach, which obtains an optimally reduced finite element model of the structure, which is coupled with a boundary element model of the acoustic fluid. [Work supported by ONR.]