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.
Keywords
Biot's theory, torsional vibrations, phase velocity, group
velocity, attenuation.