Efficiency of a tuned liquid column damper considering a seismic excitation of high frequency content and uncertainty

Abstract

In this research the behaviour of a one degree of freedom structure controlled by an optimal tuned liquid column damper (TLCD) and subjected to stochastic seismic excitations of high frequency content is studied. Uncertainty is introduced in some system parameters. The influence on the behaviour of the optimal TLCD parameters, on the efficiency measured as reduction of main system displacement and on the root mean square (RMS) displacement of the structure is analysed. An equivalent statistical linearization is performed to include the non-linear nature of the TLCD. The optimal TLCD parameters are the frequency ratio and the pressure drop coefficient. TLCD optimization is performed by minimizing the standard deviation reduction of mainframe displacement. The uncertainty is entered into the mass ratio, length ratio, and head loss coefficient. The behaviour of the efficiency is analysed, measured as a percentage reduction of the displacement when including an optimal TLCD and the RMS of the displacement, before the inclusion of uncertainty in the aforementioned parameters. It is found that the introduction of uncertainty in the period of the structure produces the highest sensitivity in the optimal parameters of the TLCD, the efficiency and the RMS of the displacement of the structure. This occurs mainly in rigid structures and with a small mass ratio.