VIBRATION SUPPRESSION CHARACTERISTICS OF MULTIPLE TUNED MASS DAMPERS WITH DUAL FREQUENCIES AND ITS APPLICATION TO BUFFETING CONTROL OF BRIDGES

DTMD is a tuned mass damper with dual frequencies.It can simultaneously reduce the vertical and torsional vibration of the bridge deck,so it has higher reduction efficiency compared to the conventional tuned mass damper.However,the reduction efficiency of the DTMD is sensitive to fluctuation in the parameters of the DTMD,which is very similar to the case of the conventional tuned mass damper(TMD).Based on multimode coupled buffeting theory,the buffeting control theory of multiple tuned mass dampers with dual frequencies(multiple DTMDs) is established in this paper.Multimode participation and aerodynamic coupling among modes are all taken into account in the formulation.A program for buffeting control and parametric study is also developed.A parametric study of a cable-stayed bridge is performed to investigate the vibration suppression characteristics of the multiple DTMDs.The effects of frequency bandwidth,the total number of the multiple DTMDs and the damping ratio of each DTMD on the multiple DTMDs are also discussed.Some advice for design of multiple DTMDs is also proposed.