Seismic response of ground-supported, three-dimensional (3-D) cylindrical liquid storage tank subjected to tri-directional components of earthquake ground motion is investigated, using coupled acoustic-structural finite element (FE) method. The FE modeling of the interaction is carried out in Abaqus® software. In this method the tank wall is modeled using shell elements and contained liquid in tank using acoustic elements. The acoustic elements are based on linear potential theory having single pressure degree of freedom at each node. The parametric study for broad and slender tanks subjected to tri-directional components of Imperial Valley, Kobe and Northridge earthquake ground motions are evaluated. The time history responses of sloshing displacement and base shear are obtained and compared with the bi-directional components of earthquake ground motion. It is observed that sloshing displacement and base shear has increased under tri-directional components of earthquake ground motion. The hydrodynamic pressure distribution along the height of tank is also evaluated.

Keywords: Base shear, Coupled acoustic-structure, Finite element, Liquid storage tank, Sloshing, Tri-directional components.