Experimental and numerical study of the response of cylindrical steel tanks under seismic excitation

Abstract

To improve the structural seismic response of liquid storage tanks, in the last 50 years, many researchers have developed different mathematical models, ranging from those based on discrete elements such as simplified two-mass models to those involving fluid–structure interactions by complex formulations. To provide a broad overview on the scope and accuracy of different numerical linear models, in this paper, a comparative study based on the dynamic response assessment of cylindrical ground-supported containers under seismic excitation is conducted. The dynamic response in terms of liquid sloshing height, base shear force and overturning moment is analysed by means of: (a) a simplified mechanical model in which the behaviour of the liquid is represented by a discrete mass-spring system; (b) a complex model based on a Lagrangian fluid finite element approximation and (c) an experimental scaled model whose measured response is considered as benchmark. To obtain robust estimators of the structural response, three different types of cylindrical tanks, including broad and slender tanks, subjected to real ground acceleration time-histories are studied. The results indicate that the finite element model gives good approximation for all response parameters and the simplified mechanical model underestimate the sloshing height and overestimate base shear force and overturning moment.