Optimum Absorber Parameters for Tuned Liquid Column Dampers

Abstract

Tuned liquid column dampers (TLCDs) are a class of tuned liquid dampers that impart indirect damping to the primary structure through oscillations of the liquid column in a U-shaped container. The energy dissipation in the water column results from the passage of the liquid through an orifice with inherent head-loss characteristics. The overall damping in a TLCD depends on the head-loss coefficient and the velocity of the oscillating liquid, and it is nonlinear due to the quadratic damping term. Using the TLCD theory and the equivalent linearization scheme, a new approach has been developed that helps to compute the optimum head-loss coefficient for a given level of wind or seismic excitation in a single step, without resorting to iterations. The optimal damping coefficient and tuning ratio of a TLCD using a single degree of freedom system under the white noise and a set of filtered white noise excitations representing wind and seismic loadings is presented. Optimum values of damping have also been investigated for multiple TLCDs. An example is presented to demonstrate the performance of multiple TLCDs in controlling multiple modes under wind excitation.