ABSTRACT
Broadband environmental vibration excitation coming for example from wind, ocean wave and earthquakes are especially dangerous for flexible tall structures (e.g. wind turbines, towers or cable-stayed bridges). Liquid Dampers have been studied for almost thirty years in terms of their capability for suppression of vibration in these types of structures. The work presented in this paper will focus on Tunes Liquid Column Dampers and non-linear damping identification. Experimental test were conducted on the test rig with the white noise excitation with use of hydraulic shaker. Exponential decay of the displacement of the water level in the columns was measured and analysed. Identification procedure was conducted in few steps, i.e. mode separation with use of Continuous Wavelet Transform was done at first, and then identification of instantaneous damping ratio for 1st mode of vibration. It will be shown that damping ratio is a non-linear and depend on the level of vibration.
