Rib resonances present in the scattering response of a ribbed cylindrical shell

The presence of ribs in an evacuated, finite cylindrical shell, placed in a fluid medium, produces highlights in its scattering response at certain resonant frequencies. These resonances are identified from the end-incident bistatic response of a ribbed cylindrical shell and are shown to be produced by the flexural vibrations of individual ribs satisfying the boundary conditions of an annular plate.