AXISYMMETRICAL WAVE-PROPAGATION IN FLUID-LOADED CYLINDRICAL-SHELLS .1. THEORY

An analysis is carried out of axisymmetric waves propagating along fluid-loaded cylindrical shells within the framework of linear elasticity and classical perfect-slip boundary conditions at the solid-fluid interface. Numerical solutions are obtained for various axisymmetric eigenmodes for a cylindrical shell in vacuum; a cylindrical shell surrounded by a liquid of infinite radial extent; a hypothetical liquid column with both the stress-free and displacement-free boundary conditions; a cylindrical shell with a liquid core; and a cylindrical shell immersed in an infinite liquid. Numerical results are obtained for both the radiating (leaky) and nonradiating eigenmodes of the system by a careful search of the complex eigenfrequencies of the associated boundary value problem. In particular, attenuation of leaky modes due to radiation of energy into the surrounding medium is expressed in terms of the imaginary part of the eigenfrequency. Computational results are presented for the dispersion curves as well as the displacement and stress amplitude component distributions along the radial direction for various propagating modes of the system. Practical benefits from such analyses are discussed.