臺灣博碩士論文加值系統

張索塔式鑽油台係由樑構架(或鐵塔)、甲板及繫索等三大部分所組成。本文將樑構架視為一細長的剛性直立圓柱，並分別以等效彈簧及纜索元素來模擬各繫索，而提出等效彈簧數學模型及有限元素數學模型，最後則以線性波理論及 Morison 方程式來求整個鑽油台所受之外力，以探討鑽油台在波浪作用下之動態反應。
本文之主旨，除了比較兩種數學模型之優劣點外，繫索預張力之大小，繫索最上端繫泊點之垂向位置，繫索之佈置情況，以及波浪頻率等因素，對鑽油台動態反應之影響亦有詳細的研究。

The guyed tower platform is maked up by three major components , the frame (tower) , the deck and the mooring system . In this paper , the frame is considered as a slender , rigid upright cylinder . And the mooring guy lines are simulated using equivalent spring and cable element , respectively . Therefore we can bring up two mathematic models of equivalent spring and cable element . In final , by linear Airy wave theory and Morison equation the external forces acting on the whole tower are calculated , as a result , the dynamic responses of the tower under waves is discussed .
Besides comparing the discrimination between the two mathematic models , the substance of this paper also includes the detailed researchs of the effects for dynamic responses of the tower as considering the factors of the cable's pretension , the vertical position of the up mooring point , the outlay of mooring cables and wave frequency , et.

第一章 緒論 1
第二章 將纜索視為等效彈簧之運動方程式 4
2-1 張索的勁度矩陣 4
2-2 鑽油台之運動方程式 9
第三章 將纜索視為有限元素之運動方程式 12
3-1 纜索之有限元素分析 12
3-2 整個鑽油台之運動方程式 17
第四章 動態分析 20
4-1自由振動分析 20
4-2阻尼矩陣 21
4-3外施負荷─波浪力 22
第五章 數值分析結果與討論 25
5-1 等效彈簧模型與有限元素模型之比較 26
5-2 繫索預張力對鑽油台動態反應之影響 28
5-3 纜索上端繫泊點之垂向位置對鑽油台動態反應之影響 28
5-4 波浪頻率對鑽油台動態反應之影響 31
5-5 繫索佈置情況對鑽油台動態反應之影響 33
5-6 偶合效應( coupling effects )對鑽油台自然頻率之影響 35
第六章 結論 38

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