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論文中文名稱:改進局部柔度法於梁結構損傷診斷之研究 [以論文名稱查詢館藏系統]
論文英文名稱:Improved local flexibility method for damage detcction of beam structure [以論文名稱查詢館藏系統]
院校名稱:臺北科技大學
學院名稱:工程學院
系所名稱:土木與防災研究所
畢業學年度:101
出版年度:102
中文姓名:蕭勝元
英文姓名:Shen-Yuan Shiao
研究生學號:100428003
學位類別:碩士
語文別:中文
口試日期:2013-07-10
論文頁數:117
指導教授中文名:廖文義;許丁友
口試委員中文名:柴駿甫;黃尹男
中文關鍵詞:局部柔度法旋轉位移模態廣域應變梁結構損傷診斷
英文關鍵詞:local flexibility methodrotatory displacement mode shapesmacro strainbeam structuredamage detection
論文中文摘要:局部柔度法(Local flexibility method)是藉由量測模態參數便可判斷梁結構之局部剛度變化。其方法之基本條件之一,係使用一虛力使其所導致之應力在局部結構區域不為零,其他區域為零;本研究改進之擬局部柔度法(Pseudo local flexibility method),係打破此一基本條件,以換取較佳之診斷結果。本研究將此方法應用於一連續梁及兩端固定梁,並進行數值模擬及實際試驗之驗證。其結果與應用局部柔度法之結果相比,顯示此方法可利用較少量之模態,更準確地診斷超靜定梁結構之損傷位置及程度。本研究中提出另一種改進的局部柔度法,亦打破傳統側向振動訊號量測之限制,改為量測梁結構廣域應變之振動訊號,並利用此訊號進行系統識別得到廣域應變模態形狀,再將其轉換成為「旋轉位移」模態形狀,即可應用局部柔度法之原理進行損傷診斷。本研究將廣域應變量測應用於一簡支梁,並進行數值模擬及實際試驗之驗證;其數值模擬結果顯示,使用相同模態數量時,與使用「側向位移」模態形狀之結果相比,確實有佳的診斷結果;試驗結果顯示,使用「旋轉位移」模態形狀,與使用「側向位移」模態形狀之結果相比是相差不多,可能是因為實驗過程中側向振動訊號量測之訊雜比較大。
論文英文摘要:The local flexibility method(LFM),which can determine local stiffness variations of beam structures using measured modal parameters,is founded on virtual forces that cause nonzero stresses within a local part of the structure and zero stresses in the other parts of a structure.In this study,the pseudo local flexibility method(PLFM) which break the “zero stresses rule” for better damage detection results is proposed. The proposed approach was verified by numerical studies and experimental study of a continuous beam and fix-end beam.The results show that much fewer modes are required for the PLFM to estimate the damage locations and extents with acceptable accuracy.In this study another modification of LFM was proposed.The “rotatory displacement” mode shapes were extracted from macro-strain vibration signals.These rotatory displacement mode shpaes were employed to detect damage of a beam structure utilizing the local flexibility method.The proposed approach was verified by numerical studies and experimental studies of a simply supported beam. Using the same number of modes,the numerical studies results was better comparing to the one using “lateral displacement” mode shapes.The experimental results show that using “rotatory displacement” mode shape has similar damage detection ability comparing to using “lateral displacement” mode shape,probably due to very large signal to noise ratio during experiment.
論文目次:中文摘要 I
英文摘要 II
誌謝 III
目錄 IV
表目錄 VI
圖目錄 VIII
第一章 緒論 1
1.1研究動機與目的 1
1.2文獻回顧 3
1.3研究內容 6
第二章 理論 8
2.1局度柔度法 9
2.2擬局度柔度法 14
2.3應用模態廣域應變之局部柔度法 23
2.4隨機子空間識別法之簡介 25
2.5柔度矩陣 28
第三章數值模擬 30
3.1擬局部柔度法 30
3.1.1模型描述 30
3.1.2分析方法 32
3.1.3分析結果與比較 32
3.1.3.1連續梁之分析結果 32
3.1.3.2小結 36
3.1.3.3兩端固定梁之分析結果 36
3.1.3.4小結 37
3.2應用模態廣域應變之局部柔度法 37
3.2.1模型描述 37
3.2.2分析方法 38
3.2.3分析結果與比較 38
3.2.4小結 41
第四章、梁結構試驗 57
4.1 試驗儀器介紹 57
4.2 分佈式長範圍光纖光柵感測器製造簡介 58
4.3 擬局部柔度法 58
4.3.1 試體描述 58
4.3.2 試驗結果與比較 58
4.3.3 小結 60
4.4 應用模態廣域應變之局部柔度法 61
4.4.1 試體描述 61
4.4.2 試驗結果與比較 61
4.4.3 小結 64
第五章、結論 113
5.1 擬局部柔度法 113
5.2 應用模態廣域應變之局部柔度法 115
5.3 未來研究方向 116
參考文獻 117
論文參考文獻:1.Rytter A. (1993) Vibration based inspection of civil engineering structures. PhD. Thesis, Alborg University, Denmark
2.Toksoy, T. and Aktan, A. E., (1994), “Bridge-Condition Assessment By Modal Flexibility,” Experimental Mechanics, Vol. 34, pp. 271–278.
3.Bernal D., (2002) “Load Vectors for Damage Localization,” Journal of Engineering Mechanics, Vol. 128, No. 1, pp. 7-14.
4.Reynders E. and De Roeck G., (2010) “A Local Flexibility Method for Vibration-based Damage Localization and Quantification.” Journal of Sound and Vibration, Volume 329, Issue 12, pp. 2367-2383.
5.Abdo, M. A.-B. & Hori, M. (2002), A numerical study of structural damage detection using changes in the rotation of mode shapes, Journal of Sound Vibration, 251(2), 227–39.
6.Li, S. Z. & Wu, Z. S. (2007), Development of distributed long gage fiber optic sensing system for structural health monitoring, Structural Health Monitoring, 6(6), 133–43.
7.許丁友,(2010),土木基礎結構損壞偵測技術:含非線性環境影響之考慮,博士論文,國立臺灣大學工學院土木工程學系
論文全文使用權限:同意授權於2013-08-26起公開