摘要
本研究目的乃在發展一套大區域的非破壞檢測的振波技術來找出管路中的缺陷或裂縫。在非破壞檢測管路裂縫的方法中，一般在化學、石化工業或核能電廠中常用的有液體滲透法、渦電流法、超音波法、音洩法、及射線檢驗法…等等。在實作中，常常因為工作的需要，擇一或使用多種方法混合使用，來達到檢測的目的。以上所提的方法，都各有其優缺點，但是就一個大管路系統而言，這些方法多半都僅適用於局部之檢驗，不但費時耗工，更容易產生量測時人為之誤差。本研究即針對上述問題，利用當管線產生裂縫、腐蝕、或其它缺陷時，其軸向和徑向應力會發生變化，同時其共振頻率也會變化的物理現象，以實驗收集分析管線有裂縫或其它缺陷時之頻譜分佈，進而確認這些缺陷的特性，找出定性及定量之相關數據，建立檢測流程、管路維修汰換、及評估管路使用壽命的基準。本研究之成果當有助於確保整個管路系統的完整性，以避免重大災害及損失。

Abstract

The objective of this research is to develop a vibration wave technique for pipeline inspection globally. It is known that the pipeline systems are widely used in chemical industry, petroleum company, or nuclear power plant. In addition, the pipeline systems are also very danger since they usually carry high pressure, high temperature, or even highly corrosive fluids. Therefore, the need for careful nondestructive testing on frequent base to determine the damage of the pipeline and the need for repair arise. The nondestructive testing methods usually used to evaluate the cracks in a pipeline are liquid penetrant method, eddy current testing, ultrasonic testing, acoustic emission method, and radiographic inspection, and etc. Technicians will usually apply one of or the combination of the methods to get the testing job done. However, the above-mentioned techniques (except for acoustic emission) can only inspect a small area or spot of the pipeline, which is very time consuming for evaluating the whole pipeline. The error will also build up easily since the technicians have to perform the measurement repeatedly.
To overcome the above-mentioned problems, this research proposes a vibration wave technique to measure the resonant frequency and the vibration mode of the whole or a long pipeline. The experimental results can be used to characterize the damage in the pipeline. The knowledge obtained from the research can also be used to define the criteria of inspection or repair procedures and life cycles of the pipeline.

目錄

謝誌 I
目錄 II
表目錄 IV
圖目錄 V
中文摘要 XI
英文摘要 XII
第一章 緒論 1
1.1前言 1
1.2本文架構 3
第二章 理論分析 4
2.1理論分析 4
2.1.1均勻樑之振動分析 4
2.1.2不均勻樑之振動分析 8
2.1.3圓筒管之振動分析 10
2.1.4圓環上裂縫對共振頻率的影響 17
2.2數值分析 17
2.2.1軟硬體介紹 17
2.2.1.1電腦硬體設備 18
2.2.1.2套裝軟體簡介 18
2.2.2軟體之工作原理 19
2.2.2.1 FEM之原理 19
2.2.2.2 MARC之原理 25
2.2.2.3算例 29
第三章 實驗系統 37
3.1管件檢測 37
3.1.1實驗儀器及其架構 37
3.1.2作動原理 37
3.1.3管件規格與邊界條件 37
3.1.4量測方式 39
3.2有限元素的解析 39
3.2.1幾何形狀及模型建立 40
3.2.2邊界條件設立 40
3.2.3材料性質 40
3.2.4幾何性質 41
3.2.5分析之種類及型態 41
第四章 結果與討論 50
4.1自然頻率及振模之實驗量測 50
4.1.1直形管件之實驗量測 50
4.1.2彎形管件之實驗量測 52
4.2以有限元素法模擬瑕疵管之自然頻率及振模 53
4.2.1前言 53
4.2.2瑕疵管之結果與討論 53
4.2.3誤差說明 55
第五章 結論與建議 105
5.1結論 105
5.2建議與未來展望 106
參考文獻 108
附錄A 111
附錄B 119

參考文獻

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