HHT於斜張橋振動頻譜之研究

The Investigation of the Vibration Spectrum of Cable-stayed Bridge using Hilbert-Huang Transform

黃廷立(Ting-Li Huang)

指導教授 ： 張達德

中原大學/工學院/土木工程學系/碩士(2008年)

https://doi.org/10.6840/cycu200800453

摘要

全球經濟的快速發展，橋梁工程設計不再只有安全性方面的要求。國內外重大交通建設的陸續推展，在如何有效利用資源及在最佳化設計觀念下，使用較少的材料建造出符合安全性、美觀性、環保、經濟及舒適度等要求下，長跨徑、高橋墩的橋梁結構型式逐漸取代傳統的短跨徑、矮橋墩，已成為未來興建橋梁結構的優先考量，橋梁運輸系統將成為人們所倚重的交通工具，如何確保行車安全實屬重要課題。目前國內外所採用的橋梁結構檢測方法，無法提供即時與有效的橋梁全面損傷資料，故無法即時給予橋梁適切的安全維護與檢修。
本文應用希爾伯特-黃轉換來分析斜張橋的振動訊號，此理論的創建“經驗模態分解法”具有完整性、幾乎正交性及可適性。可適性可表達原訊號之物理特性，藉以處理非線性及非穩態的訊號。因為這種方法的特性，斜張橋結構行為複雜，屬於非線性且非穩態的訊號，因此本研究主要探討希爾伯特-黃轉換應用於解析現地橋梁振動訊號之可行性與適用性，並由頻譜圖的結果來檢視橋梁結構系統的完整性。
本研究於分析過程中，由不同篩選次數與停止準則之設定，並加入了正交性指數的檢核，增進經驗模態分解結果的正確性。研究結果顯示，可分析比對得到較佳之結果，且藉由希爾伯特-黃轉換可確實解析現地斜張橋橋面的振動訊號，獲得橋面振動頻率，並由頻譜圖中獲知橋梁結構完整性是否完整。

關鍵字

橋梁振動頻率 ； 經驗模態分解法 ； 希爾伯特-黃轉換

並列摘要

In the fast developing global economy, the design and engineering of the bridge require not only security features, but domestic and foreign transportation facilities call for the effective use of resources. Fewer materials are used in construction while meeting the requirements for safety, elegance, convenience, and being environmentally-safe and economical. The long span and the bridge’s tall suspension towers replace the traditional short span and low bridges. It has become the new standard of bridge building. The bridge will become an important transportation device that people will think highly of. An important aspect is to guarantee the safeness of the bridge. Presently, domestic and international bridge safety examination methods are unable to provide immediate comprehensive damage material. Therefore, they are unable to provide appropriate maintenance and renovation for the bridges.
In this article, by using a series of Hilbert-Huang transform to analyze the vibration signal of the bridge. This data analysis method is based on the empirical mode decomposition, has completeness、orthogonal and adaptively. In terms of adaptively, this method can analyze nonlinear and non-stationary signals. Based on this method’s properties, the structural behaviors of cable-stayed bridges are complicated and belong to nonlinear and non-stationary signals. Consequently, this research mainly inquires into Hilbert-Huang transform to apply in analyzing bridge vibration signals in situ of the feasibility and the applicability, and by the result of spectrum to examine the integrity of bridge structure system.
Adding the orthogonal index to check the decomposed result in this research by screening a number of times, it improves the accuracy of empirical mode decomposition result. In terms of result, the effect of decomposition is goodness, and by Hilbert-Huang transform can really analyze the vibration signal of the bridge. By obtaining the bridge vibration frequency and by using spectrograph, we can see if the integrity of bridge structure is secure.

並列關鍵字

Vibration Frequency of The Bridge ； Empirical Mode Decomposition ； Hilbert-Huang Transform

參考文獻

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