Theoretical Investigation on the Impact of Two HDR Dampers on First Modal Damping Ratio of Stay Cable

Abstract

Stay cables are one of the vital components of a cable-stayed bridge. Due to their flexible nature, stay cables are vulnerable to external excitation and often vibrate with large amplitude under wind action which leads to the fatigue failure of the cables. To suppress such kind of large amplitude vibration by improving the damping ratio of the cable various dampers such as magnetorheological damper, friction damper; oil damper; or high damping rubber (HDR) damper are utilized and gained popularity over time. This paper focuses on improving the damping ratio of stay cables using a combination of two HDR dampers. First, the theoretical model is formulated considering cable bending stiffness to evaluate the damping effect of cable-HDR dampers system. Then, the impact of various design parameters of HDR dampers on cable damping considering the cable stiffness is performed. The comparative analysis of results shows that the considered parameters such as loss factor, spring factor, and installation location of dampers have much effect on the stay cables damping ratio. Finally, the optimal parameters of the two HDR dampers are proposed for damper design.

So sánh hiệu quả giảm chấn của thiết bị cản gắn bên trong và gắn bên ngoài dây văng có xét đến độ cứng chống uốn của dây văng

“…Theo Fujino và Hoang [8], Nguyen và Nguyen [10], Nguyen và Vo [14] phương trình dao động của hệ dây cáp văng gắn thiết bị cản có xét đến độ cứng chống uốn EJ của dây văng như sau:…”

Free vibration of a taut cable with internal high damping rubber dampers and an external negative stiffness damper

“…They are known to be effective for suppressing high-frequency vibrations of cables. 62 The combination of an internal HDR damper and external dampers or two internal HDR dampers has been used to suppress the vibration of cables in actual cable-stayed bridges. 63-66…”

Effectiveness of High-Damping Rubber (HDR) Damper and Tuned Mass—HDR Damper in Suppressing Stay-Cable Vibration

“…To mitigate the cable's high-mode vortexinduced vibration, Di et al [28] proposed the vibration reduction measures of installing double dampers (i.e., HDR damper and viscous damper) on the cable and carried out research on the system. Recently, Nguyen et al [29] established a cable-two-HDR-damper system model by considering the cable's bending stiffness, and they analyzed the combined influence of two HDR dampers on the cable's first modal damping ratio. Compared with the damper installed on the cable end with support, tuned mass dampers (TMDs) or similar unsupported absorbers have better application prospects.…”