裝設阻尼器之斜張橋橋面板與纜索互制 效應研究

Investigation on deck-stay interaction of cable-stayed bridges with attached dampers

葉哲維(Jhe-Wei Ye)

指導教授 ： 劉明怡

中原大學/工學院/土木工程研究所/碩士(2014年)

https://doi.org/10.6840/cycu201400869

摘要

本研究考慮纜索傾角、纜索初形，以及橋面板與纜索互制效應等三種條件下，執行黏性阻尼器對於斜張橋纜索之減振效用評估。首先，分別建立三者的有限元素模型；接著，進行複數振態分析，分別計算三者之系統於各個振態的自然頻率、阻尼頻率、阻尼比、振動型態，以及阻尼比和黏性阻尼器阻尼係數之關係曲線，由此曲線可決定系統最佳阻尼比與對應的黏性阻尼器最佳阻尼係數；最後，以高屏溪橋為例，同時考慮纜索傾角、纜索初形，以及橋面板和纜索互制效應等三種條件下，執行複數振態分析決定黏性阻尼器最佳阻尼係數後，進行地震歷時分析，針對受地震力作用之系統在未裝設黏性阻尼器，亦即未控制，以及具最佳阻尼係數的黏性阻尼器之被動控制兩種條件下，分別計算其振動反應，以評估黏性阻尼器的減振效用。經由本研究成果可全面地瞭解裝設黏性阻尼器之斜張橋橋面板與纜索互制效應的力學機制，並合理地預測黏性阻尼器之減振效用。

關鍵字

橋面板與纜索互制效應 ； 黏性阻尼器 ； 斜張橋

並列摘要

Finite element models of stay cables with attached viscous dampers of cable-stayed bridges are developed in this study. Based on these models, the complex modal analysis is adopted to calculate the natural frequency, damped frequency, damping ratio, mode shape and the curve of damping ratio versus damper coefficient of viscous damper for each mode of the system. The mentioned curve can be provided to determine the optimal damping ratio and the corresponding optimal damper coefficient of viscous damper for each mode of the system. Numerical examples are presented to estimate the optimal parameters of viscous dampers and their effectiveness for vibration control of stay cables with the consideration of the cable inclination, the cable initial shape and the deck-stay interaction of cable-stayed bridges. Under considerations of these optimal parameters, the seismic time history analysis is conducted to calculate the structural responses for two types of systems: without control and passive control, which can be used to assess the effectiveness of viscous damper. The results indicate that the viscous damper with optimal damper coefficient can be applied to effectively reduce the stay cable vibration of cable-stayed bridges.

並列關鍵字

Deck-Stay Interaction ； Viscous Damper ； Cable-Stayed Bridge

參考文獻

Abdel-Ghaffar, A.M., and Khalifa, M.A. (1991). “Importance of cable vibration in dynamics of cable-stayed bridges.” Journal of Engineering Mechanics, ASCE, 117(11), 2571-2589.

Au, F.T.K., Cheng, Y.S., Cheung, Y.K., and Zheng, D.Y. (2001). “On the determination of natural frequencies and mode shapes of cable-stayed bridges.” Applied Mathematical Modelling, 25(12), 1099-1115.

Caetano, E., Cunha, A., and Taylor, C.A. (2000a). “Investigation of dynamic cable-deck interaction in a physical model of a cable-stayed bridge. Part I: modal analysis.” Earthquake Engineering and Structural Dynamics, 29(4), 481-498.

Caetano, E., Cunha, A., and Taylor, C.A. (2000b). “Investigation of dynamic cable-deck interaction in a physical model of a cable-stayed bridge. Part II: seismic response.” Earthquake Engineering and Structural Dynamics, 29(4), 499-521.

Caetano, E., Cunha, A., Gattulli, V., and Lepidi, M. (2008). “Cable-deck dynamic interactions at the International Guadiana Bridge: On-site measurements and finite element modelling.” Structural Control and Health Monitoring, 15(3), 237-264.