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

This paper proposes a systematic optimization method to design optimal multiple tuned liquid column dampers (MTLCDs) 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 TLCDs 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 different values of MTLCD mass ratios and TLCD numbers, optimal MTLCDs have been designed for both objective functions and tested under real earthquakes. The results of numerical simulations show the simplicity and effectiveness of the method. Also it has been found that the performance of MTLCDs has been affected by its mass ratio and earthquake characteristics while in this case study, increasing the number of TLCDs has had no significant effect on its performance. Finally, comparison has been made between the performance of MTLCDs 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.