Hybrid seismic control of buildings using tuned mass and magnetorheological dampers

The use of magnetorheological (MR) dampers in combination with other control devices in a hybrid mode to enhance the control of the seismic responses of building structures is a subject of topical interest. This paper reports on the development of hybrid control schemes using different combinations of MR and tuned mass dampers (TMDs) to control the earthquake responses of building frames. The performance of the hybrid control schemes was evaluated by comparing the results with those of purely semi-active control schemes using three and four MR dampers consecutively placed in the bottom storeys of the frame. For the comparison, responses were obtained using four control strategies, namely a linear quadratic regulator with a clipped algorithm, passive-on, passive-off and a newly developed control strategy called velocity tracking control, which is especially suitable for partially observed states. The study showed that a maximum increase of 40-45% control of response could be achieved using a combination of a TMD and fewer MR dampers.