A method for efficient placement of active dampers in seismically excited structures

Using supplemental active and semi-active dampers is known as an efficient way for improving structural response to earthquakes. An actual problem that should be solved by the engineer is how many dampers should be used and what is their optimal location yielding the desired structural response by minimum cost. The last one usually depends on the price of a damping unit and its connection to the frame, number of damping units and energy required for activation of the control system in order to realize the optimal control algorithm. In this paper, the following heuristic solution of this problem is proposed. This solution is based on the well-known LQG design of active dampers. It is first assumed that the LQG controlled dampers are located at each floor. Energy, dissipated in the dampers at each floor, is obtained and most effective dampers' locations are selected according to maximum contribution to the total energy dissipation. A procedure for realization of this idea is proposed. Effectiveness of the proposed method is demonstrated in a numerical example. It shows a promising way for effective improvement of structural seismic response by a limited set of damping units.