Two-stage optimum design of tuned mass dampers with consideration of stroke

This paper presents a two-stage optimum design procedure for passive tuned mass dampers (PTMDs) to reduce structural dynamic responses with the limitation of PTMD stroke. A new performance index, with the linear combination of structural response ratio and PTMD stroke ratio by a weighting factor α, is proposed. α ranges from 0 to 1.0. The larger the α, the more important the consideration of the stroke. When α equals 1.0, the PTMD is locked. The analytical results show that with little sacrifice of structural control effectiveness, the PTMD stroke can be significantly suppressed when an appropriate α is selected. The numerical simulation of a three-story building under earthquake excitations demonstrated that the proposed optimum PTMD performs as well as the conventional PTMD and its stroke is 30% reduced. Based on the analysis results, it is proved that the new optimum design concept is more flexible and useful in practical application.