Experimental and Analytical Studies of Rocking Mechanics of Unanchored Flat-Bottom Cylindrical Shell Model Tanks

Employing a few feasible physical quantities of liquid related to the rocking motion of tanks, this paper tries to understand the fundamental dynamics of the rocking motion of tanks. Introducing the effective mass of liquid for rocking motion and for rocking-bulging interaction motions, the equations of motion are derived by analogue of rocking motion between rigid bodies and tanks. Using the exclusive tanks that possess the rigid-doughnuts-shape bottom plate that guarantees the uplift region of the bottom plate and the extent of the effective mass of liquid for rocking motion, the harmonic shaking tests are carried out. The proposed procedures can stepwise trace the base shear and the uplift displacement of the model tanks used herein.