Scattering from fluid-loaded cylindrical shell with periodic circumferential constraints using analytical/numerical matching

Acoustic scattering from an infinitely long, thin elastic cylindrical shell with axially periodic circumferential constraints leads to the excitation of flexural, longitudinal, and shear waves on the shell. Of interest is the interaction of these structural waves with the discontinuous constraints, and the effect of this interaction on the resultant scattered sound field. This three-dimensional; fully coupled, structural acoustic problem is solve d using a method called analytical/numerical matching (ANM). The method com bines high-resolution local analytical solutions and low-resolution global numerical solutions to more efficiently model structural discontinuities. T he ANM local solutions have been developed to efficiently capture the rapid variation in system response across the discontinuous constraint. The loca l solutions are combined with a smooth global solution, modeled by modal me thods, to form an accurate, uniformly valid composite solution. The ANM com posite solution is more accurate and converges much more rapidly than the t raditional modal approach. An important observation is that this scattering problem exhibits considerable sensitivity to modeling accuracy and converg ence of structural response in the region of the discontinuities. Errors in these regions have an overall effect on the structure and the associated s cattered field. (C) 1999 Acoustical Society of America. [S0001-4966(99)0220 9-2].