6th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering, COMPDYN 2017, Rhodes Island, Yunanistan, 15 - 17 Haziran 2017, cilt.2, ss.4417-4425, (Tam Metin Bildiri)
© 2017 National Technical University of Athens. All rights reserved.Liquid storage tanks, one of the important components of industrial production, may be out of service for a temporary period of time or become completely unserviceable when subjected to large earthquake ground motions that may cause severe damages. Many studies in literature suggest seismic base isolation technique in protecting liquid storage tanks from the harmful effects of strong ground motions. And, the dynamic behaviors of these structural systems, which are composed of the sloshing of the fluid inside and the dynamic response of the tank itself, are directly dependent on the isolation system design. While seismic base isolation is an emerging successful earthquake resistant design method for liquid storage tanks, seismic performances of such structures may be affected negatively from potential deviations that may occur in the mechanical properties of the isolators from the nominal design values. Deviations may come into scene due to a variety of reasons such as the errors and/or uncertainties in the properties of the materials, dimensions of the elements, manufacturing methods, quality control and installation steps. In this paper, the effects of subject deviations in the mechanical characteristics of the seismic isolators on the seismic performances of liquid storage tanks equipped with nonlinear isolation systems are investigated under different historical earthquake records. To this end, sensitivity analyses are carried out by first conducting nonlinear time history analyses of a benchmark liquid storage tank mounted on a nonlinear isolation system in 3DBASIS-ME and then comparing its seismic responses including bearing displacements and sloshing displacements, which are obtained separately for nominal and deviated cases. In the context of this study, the characteristic isolator parameters including the yield force and the post-yield to pre-yield stiffness ratio are considered as the mechanical properties which may deviate from their nominal design values.