Optimal Design of Multiple Tuned Liquid Column Dampers for Seismic Vibration Control of MDOF Structures

Abstract

This paper proposes a systematic optimization method to design optimal multiple tuned liquid column dampers (MT LCDs) for improving the seismic behavior of structures. A constrained optimization problem is formulated and solved using Genetic algorithm (GA) to generate the optimum parameters of T LCDs that minimizes an objective function defined in terms of minimization of either (a) the maximum displacement or (b) the maximum acceleration of the structure. To illustrate the design procedure, a ten-storey shear frame subjected to a filtered white noise excitation has been considered and for dierent values of MT LCD mass ratios and T LCD numbers, optimal MT LCDs have been designed for both objective functions and tested under real earthquakes. The results of numerical simulations show the simplicity and eectiveness of the method. Also it has been found that the performance of MT LCDs has been affected by its mass ratio and earthquake characteristics while in this case study, increasing the number of T LCDs has had no significant effect on its performance. Finally, comparison has been made between the performance of MT LCDs and multiple tuned mass dampers (MTMDs), which show no significant difference in performance of these control systems in most of the simulated cases especially under the design record.