Free surface effects on the dynamics of cylindrical shells partially filled with liquid

This paper presents an analytical model for the dynamic analysis of thin cylindrical shells partially filled with liquid. The method used is a combination of finite element analysis and classical shell theory, and the objective is to determine the specific displacement functions which best represent the real deformations. The effect of oscillations of the free surface of the liquid on fluid-shell vibration is studied, and consideration is given to the influence of such parameters as: the circumferential mode, the axial mode, the structural damping, the length of the shell and the forces induced by the liquid. The shell is divided into cylindrical finite elements and the displacement functions are derived using Sander's thin shell theory. The stiffness and mass matrices of the shell are derived analytically. For the liquid contained in the shell, boundary conditions are prescribed and the behaviour of the liquid is expressed by a potential function. The kinetic and potential energies of the liquid are evaluated in order to establish the influence of surface oscillation on fluid-shell vibration. (C) 1997 Academic Press Limited.