長波長軌道不整對列車-軌道-橋梁動態行為之影響

Influence of long-wavelength track irregularities on the train-track-bridge dynamic response

許維倫(Wei-Lun Hsu)

指導教授 ： 洪振發

國立臺灣大學/工學院/工程科學及海洋工程學研究所/博士(2018年)

https://doi.org/10.6342/NTU201803603

摘要

本文以解決高速鐵路列車異常振動為目的，提升列車乘坐舒適度為目標。探究造成列車振動量較大之原因，可能有列車懸吊系統異常、軌道不整、橋梁撓度異常、「列車-軌道-橋梁」互制行為等等因素，而可能造成本研究標的列振動量較大的原因為隨橋跨長度而存在之長波長軌道不整，因此本研究將以「軌道不整度」影響車、軌、橋之動態行為為主要研究重點。回顧過去文獻，發現過去於長波長軌道不整對車軌橋振動之議題多以理論解析方式進行探討，針對長波長軌道不整對於橋梁軌道振動影響及理論結合現場量測之文獻較為少見，因此本文將進行軌道不整度幅值調整(軌道整正)前後之列車-軌道-橋梁動態特性量測，並以有限元素法進行軌道整正前後之動態分析，並以量測及分析結果進行軌道不整對於車軌橋影響之綜合探討。
在研究方法部分，本文首先藉由文獻回顧針對軌道不整對車軌橋影響之參數進行探討，在列車振動部分，納出軌道不整與列車振動關係之「共振車速」及「臨界波長」，在橋梁振動部分則就橋樑可能發生「共振車速」或「相消車速」進行探討。其次本研究藉由比對文獻結果，驗證本文利用顯式積分法進行求解之準確性。確認後，將本文所建立之列車子系統及橋樑子系統，以罰值理論進行輪軌接觸模擬，將兩子系統結合成單一之平衡方程式後，利用LS-DYNA求解器進行顯式積分求解。並且同步藉由現場量測之模態識別及動態量測結果驗證本研究所建立之有限元素模型。
最終利用驗證後之有限元素模型進行，軌道不整度幅值、軌道不整度波長、列車車速對於列車振動之敏感度分析。此外本文另將分析結果以國際規範之旅客乘坐舒適度、列車出軌評價指標等進行評價。
在研究成果部分，本文藉由分析及量測結果歸納出軌道不整幅值對於列車軌道橋梁之動態行為影響程度及探討軌道不整波長對於發生列車振動放大車速、橋梁共振車速之影響，並提出對於文獻中振動相消車速之補充建議。最終亦藉由前述探討之基礎提出避免列車振動放大之軌道整正方法建議及藉由藉由營運列車列車振動量反推軌道狀態之應用。
最後就本研究過程所發現之問題歸納出值得進一步探討之主題及可應用之成果，以期作為未來發展軌道核心技術本土化目標之基石。

關鍵字

軌道不整度 ； 高速鐵路 ； 動態量測 ； 有限元素分析 ； 乘坐舒適度 ； 振動

並列摘要

The purpose of this study is to investigate the abnormal vibration of high-speed trains to improve riding comfort. Inductive reasoning of abnormal vibration could be the result of suspension failure of a train, track irregularity, abnormal bridge deflection, interaction of train track–bridge, etc. Vertical track irregularities over pre-stressed concrete bridges caused by concrete creep could be a reason to enlarge train vibration. For this reason, this study focused on the influence of long-wavelength track irregularities on the train track–bridge dynamic response. Via literature review, the influence of long-wavelength track irregularities on the train track bridge is mostly studied by theoretical analysis. Furthermore, it is rare to find the literature on this field that combines in situ measurements with theoretical analysis.
For this reason, this study will investigate vibration levels of a high-speed train, track, and bridge system using 3D finite-element (FE) transient dynamic analysis, before and after adjustment of vertical track irregularities and in situ measurements.
Using the chosen research method, first this study will discuss the key parameters that influence the train track–bridge interaction response by literature review. In the train system, track irregularities will enlarge train vibration at “critical wavelengths” and “resonance speed”; in the bridge system, the passing train will enlarge
educe the bridge vibration level at “resonancecancelation speed.” Second, we will verify the accuracy of the explicit integration method, which is used in this study by alignments with literature results. After that, wheel–rail contact will be carried out by penalty method and using LS-DYNA to solve the whole train track–bridge equilibrium equation. Furthermore, the finite element (FE) model will also be verified by in situ system identification and dynamic measurement.
Finally, the verified model will be used to carry out sensitivity analysis of track irregularity magnitude, wavelength, and train speed. In addition, this study also evaluates the study results via international standards such as riding comfort, derailment index, etc.
In conclusion, this study is inductive of the influence of track “irregularity magnitude” and “irregularity wavelength” on the train, track, bridge system by both in situ measurement and 3D FE transient dynamic analysis. In addition, this study also provides suggestions for improving the “resonancecancelation speed” via theoretical analysis, and uses the above results to carry out applications, i.e., a discontinuous shimming pattern is proposed to avoid vehicle suspension resonance, monitor track situation by revenue operation train, etc.
Finally, conclusions were made regarding the topics, which are worthy of further study. Hopefully, this thesis may become a basis for localization railway research and have the ability to go abroad.

並列關鍵字

Track irregularity ； high-speed rail ； dynamic measurement ； finite-element method ； riding comfort ； vibration

參考文獻

1. Thompson, D., in Railway Noise and Vibration, D. Thompson, Editor. 2009, Elsevier: Oxford.

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3. Connolly, D.P., et al., Benchmarking railway vibrations – Track, vehicle, ground and building effects. Construction and Building Materials, 2014(0).

4. Xia He, Z.N., Dynamic interaction of vehicles and structures. 2005: Beijing: Science Press. 416.

5. Timoshenko, S.P., CV. On the forced vibrations of bridges. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 1922. 43(257): p. 1018-1019.