高速列車行經高架橋之動態反應研究

Analysis of Dynamic Response of the Viaduct Taiwan High-Speed Railway Due to Passage of Rolling Stock

林嘉欣(Chia-Hsin Lin)

指導教授 ： 王仲宇

國立中央大學/工學院/土木工程學系/碩士(2007年)

摘要

本論文乃採用台灣高鐵列車過橋之動態量測資料，將數種儀器的量測訊號，利用支配頻率之理論，針對列車與橋梁的共振問題，以外力激振方向做區別來探討，依理論找出發生共振的可能車速，同時也提出列車蛇行診斷的概念。並試圖為之前民眾所關注之高鐵車廂在某一行駛速度的振動問題，找出一合理的原因。而在橋梁微振訊號頻譜分析部分，採用FFT（快速傅立葉轉換）與HHT（希爾伯特-黃轉換）兩個方法來做分析比較;在列車過橋之動態訊號採用HHT方法，利用其時頻分析的特性，作為後續發展列車蛇行診斷之可能性。此外本論文並推導以相對轉角量測值求取撓度曲線之公式，作為以單軸向光纖測彎計研究橋梁的動態撓度之依據。

關鍵字

橋面撓度 ； 單軸向光纖測彎計 ； 蛇行 ； 支配頻率 ； 動態反應 ； 共振 ； 高速鐵路 ； 第一自然頻率 ； 希爾伯特-黃轉換

並列摘要

Riding comfort or vehicle response is an important issue that should be taken into account in the design and maintenance of high-speed railways. Since the high-speed trains can travel at a speed much higher than the vehicles moving on highways, making it possible for the excitation frequencies to coincide with the vibration frequencies of the bridge, resulting in the so-called resonance phenomenon. This paper discusses the resonant vibration of high-speed railway system due to the actions of vertical forces and transverse forces applied by wheels. The dominant frequencies of periodically vertical loading moving at various speeds are analyzed first by a new method proposed in this paper. The natural frequency of the first mode in vertical direction of a high-speed railway bridge is identified from its ambient vibration signal by the FFT and HHT methods. Then a range of resonant speeds of the train can be evaluated. To identify resonant frequencies by the transverse loading due to the hunting motion of bogie, the wave length of the motion path of wheel pairs and the inclined contact angle between the wheel and track are used as the parameters. Frequency- velocity relations for wheels freely and constrained turning are calculated. Those natural frequencies of the transverse modes of bridge identified from ambient vibration measurements are used to evaluate the range of critical speeds of the bridge causing transverse resonance.

並列關鍵字

Bending gauge ； Natural frequentcy ； high speed ； Vibration of bridges ； HHT

參考文獻

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