調頻液柱阻尼器於受風結構扭轉向之行為探討

Investigation of Tuned Liquid Column Dampers (TLCD) in Wind-Induced Torsional Motion

廖珮亘(Pei-Hsuan Liao)

指導教授 ： 吳重成

淡江大學/工學院/土木工程學系碩士班/碩士(2007年)

https://doi.org/10.6846/TKU.2007.00392

摘要

近代橋梁跨度增大，且使用質量較輕之建材，其受風作用之反應亦隨之增加，因此增設減振裝置如調頻液柱阻尼器(Tuned Liquid Column Damper, TLCD)來抑制結構扭轉向振動有其必要性。目前TLCD之應用大多集中於建築物，甚少有橋梁上之應用。因此本文之研究內容將針對結構裝設變斷面TLCD進行基本理論推導，並進行TLCD系統識別以及二自由度系統互制行為之驗證實驗。
考慮單自由度結構裝設變斷面調頻液柱阻尼器進行運動方程式推導，在簡諧外力矩擾動下解出結構與TLCD液面反應之理論解。發現在運動方程式存在一修正項，其為以往文獻所忽略，因此，建構大尺度結構與TLCD模型進行實驗驗證，同時亦進行TLCD自然頻率與水頭損失係數之率定，並藉由驗證實驗結果與理論分析結果間之比較，以釐清該修正項之重要性。
率定結果顯示，三組TLCD自然頻率之率定結果與理論值相當接近，其誤差均於5%之內。水頭損失係數則會隨著孔口板阻塞率ψ與斷面積比ν值變大而變大，並經時間歷時分析驗證。另外，互制驗證實驗顯示，大致上當外力擾動頻率於低頻及共振頻率附近時，考慮修正項時所得到之分析結果較接近實驗結果，因此在運動方程式考慮該修正項是必要的。

關鍵字

調頻液柱阻尼器 ； 水頭損失係數 ； 扭轉向運動 ； 互制行為

並列摘要

Recently, the advancement in construction technology and material has facilitated the construction of lighter bridges with even longer span. The down side effect that comes with it is the susceptibility of such structures to wind loading. Thus, the use of vibration control device, such as tuned liquid column damper (TLCD), is becoming more and more necessary. Since the application of TLCD to civil structures is mostly on buildings, the derivation of the interaction behavior between the TLCD and structure in the torsional motion will have to be addressed.
In this research, a single-degree-of-freedom damped structure equipped with a TLCD in torsional motion is considered to derive the equations of motion. Consequently, the analytical solution of the structural response and TLCD liquid motion has been derived under the excitation of harmonic loading. It was found that, in the equations of motion, there exists a modified term which is not considered in the existent literature. To justify the importance of this term, a large scale structure and TLCD models were constructed and the verification of interaction tests was conducted. Prior to the interaction tests, the properties of the TLCD and structures were also identified respectively and the values obtained were used to compute the analytical solutions from the interaction equations for comparison.
The identification results show that natural frequencies of TLCDs are quite close to the theoretical values with error less than 5%, and the head loss coefficients increase with the increase of the blocking ratio and cross-section ratio. On the other hand, the interaction tests show that experimental results are closer to the analytical solution with the modified term considered than without the modified term considered. Therefore, the incorporation of the modified term in the interaction equations of motion is essential.

並列關鍵字

Tuned Liquid Column Damper ； Head Loss Coefficient ； Torsional Motion ； Interaction

參考文獻

24. J. C. Wu, “Experimental Calibration and Head Loss Prediction of Tuned Liquid Column Damper,” Tamkang Journal of Science and Engineering, Vol. 8, No. 4, pp. 319-325 (2005).

1. J. D. Holmes, Wind Loading of Structures, Spon Press, London, 2001.

2. Robert J. McNamara, “Tuned Mass Dampers for Buildings,” Journal of the Structural Division, Vol. 103, No. ST9, pp. 1785-1798 (1977).

3. K. C. S. Kwok, B. Samali, “Performance of Tuned Mass Dampers under Wind Loads,” Engineering Structures, Vol. 17, No. 9, pp. 655-667 (1995).

4. K. Fujii, Y. Tamura, T. Sato, T. Wakahara, “Wind-Induced Vibration of Tower and Practical Applications of Tuned Sloshing Damper,” Journal of Wind Engineering and Industrial Aerodynamics, 33, pp. 263-272 (1990).