Acoustic scattering from immersed composite cylindrical shells: Existence of zero group velocity circumferential waves

Some Lamb waves in a plate and some circumferential waves in a one-layer cylinder are characterized by the resonance frequencies where the group velocity is vanishing while the phase velocity remains finite. This paper investigates on the existence of these special waves which call zero group velocity waves (ZGV waves) in the case of the copper/polymer composite cylindrical shell immersed in water and filled with air. The acoustic scattering of a plane wave from this composite cylindrical shell is analyzed in the reduced frequency range (0.1