Radial vibrations of an infinitely long poroelastic composite hollow circular cylinder

The problem of radial vibrations of an infinitely long poroelastic composite hollow circular cylinder is solved by employing Biot’s theory of wave propagation in poroelastic media. A poroelastic composite hollow cylinder consists of two concentric poroelastic cylindrical layers both of which are made of different poroelastic materials with each poroelastic material as homogeneous and isotropic. The boundaries of composite hollow poroelastic cylinder are free from stress. The frequency equations of radial vibrations of poroelastic composite hollow cylinder with rigid core, poroelastic composite solid cylinder, poroelastic composite solid cylinder with rigid casing and of rigid core and poroelastic composite bore are derived as particular cases. Non-dimensional frequency is computed as a function of ratio of thickness to inner radius of core. The results are presented graphically for two types of poroelastic composite cylinders and then discussed.