On the numerical assessment of the resonant sloshing responses in 3D multi baffled partially liquid-filled steel cylindrical tanks shaken by long-period ground motions

Abstract

This study displays a coupled numerical process to scrutinize the sloshing response for multi baffled flexible cylindrical container subjected to lateral excitations. The developed algorithm is based on a coupled three-dimensional boundary element-finite element approach which allows computing sloshing natural frequencies, as well as seismic responses. The intricate liquid region is divided into several simple sub-regions so that in each liquid sector the Laplace equation is solved by introducing interface influence matrix and, finite element route is employed to model the tank shell. This process has a substantial influence on lessening computational cost and a good precision in evaluating the response of the whole system. The time variations of sloshing responses, base forces, the maximum hydrodynamic pressure and shell radial displacement in relation to various system parameters such as the liquid-fill depth, tank geometry and baffles arrangement are deliberated in detail. From these examinations, it may be concluded that with the installation of baffle rings inside the liquid tank, the dynamic response of such structures during severe earthquake ground shakings can be significantly diminished. Furthermore, in the exceptional case of long-period ground excitations, the seismic response of multi baffled containers may be controlled by the baffle rings only at particular statuses of shallow structures. For the case of slender containers, special considerations would be required to be assigned to the design of baffle plates believed to experience long-period seismic excitations. The proposed coupled numerical procedure can serve as a basis for future analysis of multi baffled cylindrical tanks in conjunction with fluid due to severe long-period earthquakes.