Hybrid passive control system of TLD and TMD for seismic response mitigation of Tall Buildings

Abstract

Using Tuned liquid damper is one of the passive control methods in structures. The system consists of some water tanks that are installed at the highest level of structure. The water turbulence created inside them is used to reduce the seismic oscillation of structure. Therefore, the damper characteristics (tank size and depth of water in it) should be selected in such a way that the frequency of water in the reservoir is tuned with the frequency of structural vibrations. The controlling force to reduce the structural vibrations is created by the pressure difference caused by the difference in surface levels of the liquid in the end chambers which acts as a shear force at the bottom of tanks. It is required to obtain the water surface level at different times to calculate the controlling force caused by tuned liquid dampers. In the present study, the parameters of damper have been simultaneously minimized by Genetic Algorithm (GA) method and based on single-purpose function (displacement of the top story) and multi-purpose functions (displacement and acceleration of the top story). Optimal Pareto Front objective functions are utilized to achieve optimal responses. A 20-story building has been investigated as a numerical example to carry out this study. In this study the comparisons between TLD system and TMD system, i.e. integrated TLD-TMD system is made with the application of Genetic Algorithms. The author codes all the numerical solutions and Genetic Algorithm program.