Torsional Vibration Control Of Complex-shaped Tall Structures Under Earthquake Using Tuned Liquid Damper

From theoretical and seismic disasters, it can be concluded that the seismic response is not only in translational direction, but also in torsional direction. There are two respects that are responsible for the torsional response of structures. First, there exists torsional component for the motion of ground or phase delay for the different sites of ground under earthquake. Second, structure has eccentricity for the inconsistency between the center of mass and stiffness. The torsional components can lead to serious destroies, especially for the eccentric structures. So, the torsional response control problem of eccentric structures under earthquake is very important. The thesis focus on the seismic response control of complex structures using tuned liquid dampers and the main contents are summarized as follow:(1) The parameters of Circular Tuned Liquid Column Dampers (CTLCD) are analyzed. Based on the motion of equation for CTLCD in which the nonlinear damping of CTLCD is equivalently linearized, the optimal parameters of CTLCD under purely torsional condition are studied and the results show that CTLCD is an effective control device on torsional response.(2) Baesd on the parameter optimization method of liquid dampers using Genetic Algorithm, the TLCD and CTLCD are induced to control the torsional responses of the eccentric buildings under seismicexcitation. The results show that the liquid dampers with optimal parameters can effectively reduce the torsional response of eccentric buildings when the objective function of optimization is selected to consider each degree of freedom.(3) Two TLCDs and one CTLCD are used for seismic responses controlling of a 12-story eccentric steel building. The optimal parameters of liquid dampers are optimized by Genetic Algorithm. The structural response with and without liquid dampers under bi-directional earthquakes are calculated. The results show that the torsionally coupled response of structures can be effectively suppressed by liquid dampers with optimal parameters.