Experimental Testing of a Base Isolated Model in Laboratory Conditions

• Published in: Key engineering materials 2014-03, Vol.601, p.219-222
• Main Authors: Cruciat, Radu, Ghindea, Cristian Lucian
• Format: Article
• Language: English
• Subjects: Damping; Extrapolation; Finite element method; Frequency domains; Isolation systems; Mathematical analysis; Mathematical models; Vibration
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.601.219

A method used world-wide to reduce the effects of seismic motion it is represented by the base isolation of the structure. The application of this method aims to an increase of the base flexibility in the horizontal plane. In order to illustrate the advantages of the base isolation system an experimental analysis in frequency domain was achieved. The test specimen was represented by a small scale model of a simple structure. Frequency domain analysis has allowed a comparison between the response of the structure with and without base isolation. The comparison pointed the positive effect of base isolation in order to reduce the resonant response of the fixed base structure. In order to validate the experimental results and to extrapolate response to cases closer to real isolation systems, finite element models of the structure with and without isolated base were made. The numerical models were calibrated with experimental models in terms of natural vibration period and damping ratio and they were designed to describe the real experiments, as far as possible. Comparative response analysis of the two models has allowed experimental data validation and the numerical model acceptance. The average error between the two response curves in the frequency domain was considered acceptable, taking into account the general precision of an experimental test. In order to fill some gaps due to boundary conditions of the experiment a finite elements analysis was performed to extrapolate the response of the isolated structure for higher values of the damping ratio at the base isolation system level and for random seismic motion.