鋼軌扣件為軌道系統中一個很重要的原件，有穩定鋼軌的用途以減低振動的傳遞，因此必須先了解扣件的本身的自振頻率，以進一步了解與其他物件的相互影響，如當車輛行駛不同速度、扣件預壓力鬆緊的狀況不同，都會影響軌道系統中扣件的狀況，因此以扣件頻率的變化可以作為判定的依據。

本論文使用有限元素軟體ABAQUS建立扣件模型進行分析，以了解扣件在無邊界時的模態振型，再利用實驗衝擊槌的技術將所量測到的加速度值取得頻率響應函數(FRF)得之扣件的自然頻率，用此方法以驗證模型的材料參數，使與實際扣件的振動行為相同，未來可以利用此模型使用在不同研究議題上。而實際上的扣件位於軌道系統中，因為邊界條件而有不同的振動特性，因此到現地進行量測，利用衝擊槌與列車兩種振源，了解外力頻率在該邊界扣件系統中的振動行為。本研究透過現場的量測，發現扣件SKL15的 F點的振動均大於G點，與現實斷裂情形都斷裂在F點吻合。從束制扣件模態分析中，配合實驗所量到的頻率與現場光帶分布的觀察，了解振動行為與其可能破壞的模態振動，然而因營運安全的考量列車經降速，研究過程未量測到較高車速下軌道系統與扣件系統的反應，因此暫時無法證實斷裂的確切原因。

Rail fasteners is one of the most important component for railway system. But we also hear that fasteners break in a specific location, which mean fasteners in railway system have its mechanical vibration characteristics that cause damage, (in this study we called point F). So first we need to know the natural frequencies of rail fasteners to help us further understand the interaction of different position of a fastener itself and the behavior of installing from field condition, so the change of natural frequencies can be used to determine.

The thesis adopted finite element method ABAQUS and experimental modal analysis method to find out fasteners natural frequencies and validate the material parameters of finite element model, so that the vibration behavior of fastener model can be the same as real one. Also we measure fasteners in railway system to consider its vibration characteristics in its boundary conditions. Field trials using impact hammer and train two kinds of vibration source to understand the vibration behavior of fastening system with boundaries. The result of field measurement is the amplitude of vibration fasteners of point F is greater than point G which coincide with the cracked position of fasteners in fact. Although we know Vossloh fasteners have asymmetrical force vibration, the study still didn’t measure the train speed which easily damage the fastener system and cannot clearly confirm the first crack of point F.

[1] Thompson, D. J. and Verheij, J. W., "The Dynamic Behaviour of Rail Fasteners at High Frequencies.," Applied Acoustics, vol. 52, pp. 1-17, 1997.
[2] Smutny, J., "Measurement and analysis of dynamic and acoustic parameters of rail fastening," NDT & E International, vol. 37, pp. 119-129, 2004.
[3] Kaewunruen , S. and Remennikov, A., "Applications of experimental modal testing for estimating dynamic properties of structural components.," Australian Structural Engineering Conference, 2005.
[4] Lakusie, S., Bartons, D. , and Bajic, A. G.," Experimental and numerical analysis of the rail fastening spring clips types SKL1–SKL12," Symposium on Experimental Methods in Solid Mechanics, 2005.
[5] Kaewunruen , S. and Remennikov, A., "Non-destructive evaluation for dynamic integrity of railway track structure.," in Proceedings of the International Conference on Structural Integrity and Failure —SIF2006, pp. 294-299, 2006
[6] Kaewunruen, S. and Remennikov, A.,"Field trials for dynamic characteristics of railway track and its components using impact excitation technique," NDT & E International, vol. 40, pp. 510-519, 2007.
[7] Pieringer, A., Kropp, W. and Thompson, D. J., "Investigation of the dynamic contact filter effect in vertical wheel/rail interaction using a 2D and a 3D non-Hertzian contact model," Wear, vol. 271, pp. 328-338, 2011.
[8] 陳柏麟、張達德、陳明新, "HHT 振動解析法應用於軌道扣件檢測研究"，先進工程學刊，vol. 3,No.4, pp. 323-330, 2008.
[9] 杜茂金, "南京地铁DTⅥ2型扣件弹条折断原因分析," 城市轨道交通研究, pp. 40-42, 2009.
[10] Chen, Z., Shin, M., Andrawes, B. and Edwards, J. R., "Parametric study on damage and load demand of prestressed concrete crosstie and fastening systems," Engineering Failure Analysis, vol. 46, pp. 49-61, 2014.
[11] 余自若,張元慶,袁媛, "高速鐵路扣件系統疲勞性能研究," 北京交通大学, 2012.
[12] 臺北市政府捷運工程局, 捷運軌道工程實務: 臺北市政府捷運工程局, pp.66-71, 2006.
[13] 黃彥賓, 王怡華, 林安祥, 楊子謄, 陳嘉昌, "軌道扣件之種類與功能要求," 技術論壇.
[14] 王其昌, 無碴軌道鋼軌扣件: 西南交通大學出版社, 2006.
[15] 若月修, "レールを固定する締結装置," 特集：鉄道を支える小さなもの, 2009.
[16] 王栢村. 實驗模態分析講義. http://cec.npust.edu.tw/e-learning/craft/index.asp