碳纤维索的局部振动对斜张桥地震反应的影响探讨-中华大学.PDFVIP

碳纖維索的局部振動對斜張橋地震反應的影響探討 Study on Effects of Carbon Fiber Composite Cable Local Vibration on The Seismic Response of Cable-stayed Bridges 苟昌煥 中華 大學土木與工程資訊學 系副 教授 摘要 在跨徑較大的斜張橋中 ，長短不一的纜索體系所涵蓋的自振範圍很大，在車輛 、地 震或風雨荷載作用下，纜索的局部振動易與橋梁體系發生耦合振動的現象 ，這種耦合振 動不但會改變斜張橋振動能量的分佈 ，同時還會影響振動體系的阻尼特性 。本文將以多 質點來模擬纜索的振動 ，並依廣義自由度的觀念 ，將纜索的振態作為自由度來考慮。在 研究中發現 ，碳纖維索對於避免產生 索橋耦合振動的表現較鋼索為佳 ，而在地震反應方 面也較鋼索為小 ，因此碳纖維索斜張橋比鋼索斜張橋在抗震上較具有優勢 。 關鍵字 : 斜張橋 ，纜索局部振動 ，碳纖維索 ，地震反應 Abstract Among large span cable-stayed bridges, the free vibration of the cable system comprising cables of different length covers a wide range. Under reaction to a vehicle, earthquake or wind/rain fall load, the local vibration of cables tends to induce coupled vibration with the bridge mechanism. This coupled vibration not only alters energy distribution of the cable stayed bridge but also affects damping characteristics of the vibration mechanism. The study simulates cable vibration with multi-particle model, and considers modal shape of cables as a “degree of freedom”according to the broader definition of generalized degree of freedom. The study finds that the carbon fiber cable, in comparison with the steel cable, has a better performance to avoid generation of coupled vibration in the cable-stayed bridge, and a lighter seismic response as well. Therefore a cable-stayed bridge with car