On torsional vibrations of infinite hollow poroelastic cylinders

Employing Biot's theory of wave propagation in liquid saturated poroelastic media, the propagation of torsional vibrations in an infinite homogeneous, isotropic hollow poroelastic circular cylinder is investigated.Considering the boundaries to be stress free, the frequency equation of torsional vibrations is obtained in presence of dissipation.The frequency equation is discussed for the first two modes in the cases of a poroelastic thin shell, a poroelastic thick shell and a poroelastic solid cylinder.Phase velocity, group velocity and attenuation are determined and computed for the first mode of vibration for two different poroelastic materials as a function of frequency.These values are displayed graphically and then discussed.