以藍姆波群波速之頻散曲線開發老劣化環氧樹脂黏結鋼板補強混凝土結構之快速檢測技術

Development of a technique for quick assessment of the deterioration of EPOXY-filled steel plate reinforced RC structure using the dispersion characteristics of Lamb waves

閻中堯(Chung-yao Yen)

指導教授 ： 鄭家齊

朝陽科技大學/理工學院/營建工程系/碩士(2012年)

摘要

研究中主要以應力波原理為基礎的檢測方法來檢測環氧樹脂黏結鋼板補強結構老劣化狀況，以頻率-波慢譜所呈現之板波模態檢測較大範圍鋼板可能剝離狀況、並計算板波基本反對稱模態之波長-波速圖、以表面波譜法之分析方式評估環氧樹脂黏結鋼板與混凝土間劣化缺陷之水平範圍。本研究是以單一接收器與單一敲擊源取得頻散曲線，利用短時傅立葉轉換及影像再分配技術波慢-頻率譜圖，再與DISPERSE程式所得到之理論解作比較分析。結果顯示，A0基本反對稱模態與理論解頻散曲線偏離之最高頻率與水平缺陷有關。計算A0模態正規化波長-波速關係中正規化波長大於3之結果的線性趨勢線斜率，能判別出鋼板與混凝土間黏結是否完善，且可初步判定缺陷大小。數值模擬與鋼珠敲擊源及可感測鋼珠敲擊器試驗對照，驗證可感測鋼珠敲擊器進行試驗之可行性，對於老化鋼板補強檢測施作可更加流暢。並以梁試體利用環氧樹脂黏結鋼板補強，製造介面裂縫後加以檢測，在測線跨越不同長度裂縫時，其A0頻散曲線之低頻無因次波長-波速趨勢線斜率有所改變，其趨勢與數值模擬及試驗結果相似，證明此方法之可行性。

關鍵字

環氧樹脂 ； 藍姆波 ； 敲擊回音 ； 鋼板補強 ； 混凝土

並列摘要

In this study, the state of deterioration of epoxy bonded steel plate reinforced structure was assessed by the method based on the principles of stress waves. The fundamental anti-symmetric modal (A0 mode) dispersion curve of the steel plate in the slowness spectrogram and the wavelength-speed diagraph were used to evaluate large range debonds of steel plate. This research is based on a single receiver with a single impact source to obtain the dispersion curves, using the STFT and reassigned spectrogram.The dispersive image was compared to the theoretical dispersion curve of the plate with the same thickness and material property. The results shows the alien

The results showed that the highest frequency for the A0 fundamental antisymmetric modal dispersion curve deviating from the theoretical one is related to the range of the defect. The slope of the linear regression line obtained from the A0 mode dimensionless wavelength vs. wave speed diagram can determinate the size of the defect. The feasibility of using sensing impact source to conduct test is verified. Using this kind of impactor can simplify the testing procedure.

For the concrete beam specimens strengthened by epoxy bonded steel plate and containing crack in the bonding interface, the testing results showed the slope of the dimensionless wavelength- wave speed relation were changed when the survey line across the crack.

並列關鍵字

Lamb wave ； Epoxy ； impact echo ； steel plate strengthen ； concrete

參考文獻

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