Masses of Fluid Contributing to Rocking Motion of Cylindrical Tanks With Partial Uplift of Bottom Plate
Accurate and easy calculation of the mass of fluid contributing to the rocking motion of cylindrical tanks with partial uplift of bottom plate, which is the effective mass of fluid for rocking motion, that for rocking-bulging interaction, effective moment inertia of fluid for rocking motion and their centroid, is proposed. Asymmetric deformation of the tank bottom plate due to crescent-like uplift is used to put quantification of the masses away from rigorous treatments. This study considers the cylindrical tank as a set of thin rectangular tanks, so-called a slice model, and puts them perpendicular to the rotational axis of the tank rock motion. Then solve a boundary-value problem of each slice model specified by uplift of the tank bottom plate and its location, the mass of fluid contributing to rocking of cylindrical tanks is quantified as the sum of that of each slice model. Values of the effective mass of fluid for rocking motion, that for rocking-bulging interaction, effective moment inertia of fluid for rocking motion and their centroid are tabulated and depicted as a function of the aspect of tanks for different values of the ratio of the uplift width of the tank bottom plate to the diameter of tank.