Benchmarking an acoustic coupling theory for elastic shells of arbitrary shape

Coupling coefficients for thin shells of arbitrary curvature based upon a ray-theoretic approach devised by the authors are benchmarked against exact and high-frequency results for canonical geometries, i.e., the spherical nd infinite circular cylindrical shells. The well-known high-frequency approximations of the coupling coefficients are found to describe their magnitude accurately but not the phase for midfrequencies (between ring and coincidence) when compared with results obtained by applying the Sommerfeld-Watson transformation to the exact modal series. The coupling coefficients characterize both the magnitude and the phase accurately and simply in terms of fundamental physical parameters. ̧ 1995 Acoustical Society of America.