Abstract:

DTMD(Dual-Frequency Tuned Mass Damper)is a new-type tuned mass damper(TMD)with dual fre-quencies.Compared with the conventional TMD,it can simultaneously control the vertical and torsional vibrations of the bridge deck.In this paper,the buffeting differential equations governing the motion of the bridge with DTMD are established based on the multi-mode coupled buffeting theory.Multi-mode participation and aerodynamic COU-piing among modes are all taken into account in the formulation.The random vibration theory is then used to solve the bufeting diferential equations of the system.Finally,parametric studies on a cable-stayed bridge are perform ed to investigate the effects of the frequency and the damping ratio on the reducing efficiency,and the dual-reduction characteristics of the DTMD for bridge bufeting control are also discussed.The results show that DTMD has higher reduction eficiency than the conventional TMD.

Key words: long-span bridge, dual-frequency tuned mass damper, bufeting control, multi-mode coupled buffeting