Improved evaluation of the resonance spectral parameters of sound scattering from the spherical thin elastic shell

The resonance characteristics of the complex amplitudes of acoustic pressure scattering by an elastic thin spherical shell are investigated. In the R-matrix approach the analytical relations for the approximate determination of the partial resonance frequencies and widths are found. The conditions for effective "background" scattering suppression and selection of resonances caused by sound radiation of the shell on the bending and membrane vibrations are obtained. For quadrupolar sound scattering by shells of average thickness a correlation between the widths of the spectral lines of the zero order symmetrical Lamb wave (membrane type of vibration) and the chemical type of the shell metal is discovered.