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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/903


    Title: 梁損傷系統之識別參數與損傷檢測之應用;Damage Assessment of Beam by an Impact-Echo Testing Method and Calculation of Damage Indices
    Authors: 劉正偉;Zheng-Wei Liu
    Contributors: 土木工程研究所
    Keywords: 梁結構;損傷檢測;互易定理;傳遞函數;損傷指標;模態振形;FRF;系統識別;reciprocal theory;transfer function;damage index;modal shape analysis;system identification;damage detection;beam structure
    Date: 2004-12-07
    Issue Date: 2009-09-18 17:15:09 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 台灣公共工程建設至今,已逐漸邁入需要的飽和並將注意的重點轉往為基本設施的維修與保養上。如何的節省人力、物力來達到快速檢測目的為目前工程界所關切之課題。 本論文首先介紹利用Graffi線彈性動力互易定理量測之觀念,配合敲擊激振與收得之結構頻率反應訊號(FRF),對結構特徵做出識別;而後將識別出的模態參數(頻率、振形等)帶入現行已知的數個損傷指標計算,並於梁結構形式的損傷識別實驗中發現:模態曲率振形變化法指標(MMC)對於單一或是雙裂縫的損傷有不錯的識別能力。而模態座標確認準則指標(CoMAC)則可在邊界及感測計安裝之外的位置提供參考。模態尺度因子(MSF)對於結構損傷嚴重時可提供程度上的依據。 本論文所建構之梁式結構之損傷檢測分析流程,可作為後續建立橋樑損傷快速檢定之參考。 In this paper, an impact-echo testing method was developed to assist engineers to assess the damage location of bridge girder through some simple measurements on the surface of bridge deck. The reciprocal theorem of elastodynamics was applied to get the transfer functions at various impact sites along the beam axis from the least number of vibration sensors distributed on the surface of beam. Mode shapes of the detected beam can then be constructed for the analysis of damage assessment. Some conventionally used damage indices, like MAC (modal assurance criterion), CoMAC (coordinate modal assurance criterion), MMC (method of modal curvature),were applied to evaluate their performance on damage assessment by real measure data. Aluminum and reinforced concrete beams of various damage conditions were tested in the laboratory. It is found that the MMC may provide better identification on damagelocation than other damage indices. Details of the data measurement, and analysis of the testing method were addressed in this paper.
    Appears in Collections:[土木工程研究所] 博碩士論文

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