導波應用於離岸風機基樁之基礎研究

Basic research of applying the guided wave to the foundation piles of offshore wind turbines

潘郁婷(Yu-Ting Pan)

指導教授 ： 宋家驥

國立臺灣大學/工學院/工程科學及海洋工程學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.00685

摘要

因離岸風力發電機(簡稱風機)身處大海，其海床表面下的樁柱基礎在受自身振動、海洋動力(波浪及海流)、或地震等外力作用後，樁柱與海床砂石之固著程度可能改變，而其固著的緊密情況將影響到風機的穩定度。因此水中樁柱有必要做定期的檢測，而導波法具有長距離傳遞且能量不易衰減的特性，入射於管線上傳遞，可擴大管線檢測範圍，故本研究以超音波換能器所致之導波法來對樁柱結構上的特性評估、規劃、設計並開發一套有效的非破壞性檢測方法及設備，對樁柱基礎做定期的評估。
因此在本研究中，將風力發電機的基樁先簡化以單一鋼管為模型代表，先建立一套導波檢測之方法，以PCdisp繪出頻散曲線圖後，找出合適之入射模態及角度，架設超音波換能器以調整入射角度至最佳狀況後，因需探討基樁位於海床中之固著程度改變與表面腐蝕的情形，故以包覆實驗模擬基樁周圍土層之包覆情形，及以人工腐蝕的方式模擬基樁表面受到腐蝕，再以所建立的導波方法進行檢測，並討論及歸納出其底部回波訊號改變之規則，以提供現場檢測人員分析訊號結果之依據，並可達到基樁結構維護監測之目的。

關鍵字

導波法 ； 超音波換能器 ； 離岸風機基樁 ； 頻散曲線圖 ； PCdisp

並列摘要

As offshore wind turbines are located in the sea, column foundation piles under the surface of the seabed which are affected by vibration, ocean power (waves and currents), earthquakes and other external forces, might affect the firmness between the foundation piles and the seabed. This will in turn affect the stability of the offshore wind turbine. Therefore, regular maintenance of the piles is very important. Since the guided wave method has long-range energy transmission and does not lose energy easily, when we use pipeline to transmit, the pipeline detection range would be greater. In this study, we will be using the ultrasonic transducer to make the guided wave method so as to assess the characteristics of the column on the surface. After which, we will start to plan, design and develop testing equipment and methods which are safe and effective in order to conduct regular assessments of the piles’ foundation.
In this study, the foundation piles will be replaced by a single steel pipe as a model represent. PCdisp will be used to draw the dispersion curve to find the suitable mode and angle. After setting up the ultrasonic transducer and adjusting it to the best settings, we will explore the firmness between the foundation piles, the seabed and the corrosion of the surface. We will then be able to design a coated experiment to simulate the coated situation, and also an artificial corrosion experiment to simulate the corrosion. By applying the guided wave method, we will analyze and judge the structural condition of the surface so as to achieve the purpose of this study.

並列關鍵字

Guided wave method ； Ultrasonic transducers ； Offshore wind turbine ； Foundation piles ； dispersion curve ； PCdisp

參考文獻

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