Axisymmetric Free Vibration Analysis of a Floating Roof in a Cylindrical Tank

抄録

Coupled oscillations of a liquid and a floating roof in a circular cylindrical tank are studied for small motions. The liquid is assumed as a perfect fluid, both floating roof and bottom plate of the tank are treated as thin plates, and the side wall is assumed rigid. The Fourier-Bessel expansion is used to obtain frequency equations. Numerical examples for the axisymmetric case are given to illustrate the effect of coupling, showing that a floating roof of small bending rigidity will oscillate approximately in sloshing (free surface oscillation) modes for lower natural frequencies, and that a bottom plate spring-supported on the foundation behaves actually as a rigid body.