The coupled vibration characteristics of multiple elastic annular baffles of the same inner radius in a partially liquid-filled rigid cylindrical container were studied. The liquid domain was divided into several simple sub-domains so that the liquid velocity potential in each liquid sub-domain was of class C1 with continuous boundary conditions. Based on the superposition principle, the general solution of the liquid velocity potential corresponding to each liquid sub-domain was obtained by means of the method of separation of variables. The coupled modes of the multiple elastic annular baffles were expressed in terms of dry-modal functions. The free surface condition, the interface conditions and coupled vibration conditions were expressed in terms of Fourier series along the liquid height and Bessel series in the radial direction, respectively. Stable and fast numerical computations were investigated by the convergence study. Excellent agreements have been achieved in the comparison of results obtained by the proposed approach with those given by the finite element software ADINA. The natural frequencies and mode shapes versus the position, the inner radius and the number of the annular baffles were thoroughly discussed.
