Pure elastic resonance scattering of an obliquely incident plane acoustic wave by a submerged infinite cylindrical shell

Until now,sound resonance scattering by a submerged elastic cylindrical shell at oblique incidence has not been extensively studied.In this paper,we derive a simple and explicit expression of the pure elastic resonance scattering function of a submerged infinite cylindrical shell excited by a plane wave at oblique incidence.For backscattering of an aluminum tube (b/a=0.8) we have calculated (a) the partial resonance spectra at n=0-7,(b) the far field total form functions and the pure elastic resonance form functions,(c) the complex resonance poles in the normalized.complex.frequency plane,and (d) the dispersion curves of the first several families of belieal waves,at various in cident angles indetails.We find-that the coincidence frequency of the l=(1) wave plays a very important role.The results given here are very helpful to understand the physical nature of the resonance and reradiation of a submerged cylindrical shell excited by sound at oblique incidence.