Finite element techniques for the free-vibration and seismic analysis of liquid-storage tanks

This paper is concerned with the refined numerical techniques for the seismic analysis as well as the free vibration analysis of liquid-storage tanks. In the numerical formulation of accurate added-mass matrix, for the construction of uncoupled-separated structural dynamic system, the liquid free-surface fluctuation is taken into consideration. In order to resolve the non-linearity and non-orthonormality of resulting frequency-dependent added-mass matrices and natural modes, we propose a rapid convergent iterative numerical scheme for computing added-mass matrices, as well as a modified numerical procedure for the seismic analysis. Through the numerical experiments with a closed-type tank, excited by a random horizontal earthquake wave, Re compare the numerical results by the proposed refined numerical techniques with those by the classical approaches, together with the detailed investigation of the proposed numerical scheme. (C) 2001 Elsevier Science B.V. All rights reserved.