船舶碰撞板結構的捲曲撕裂與褶皺破壞分析

Tearing and Folding Failure Analysis of Plate Under Ship Collisions

黃萬偉(ENG BAN WEE)

指導教授 ： 洪振發

國立臺灣大學/工學院/工程科學及海洋工程學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.00154

摘要

現在國際上大部分的貨品運輸仍然為主要以船舶運輸為主，由於經濟持續的發展，因此船舶會有愈來愈多的趨勢，因而造成船舶發生碰撞及擱淺的問題更形重要。船舶撞擊為一非常複雜的力學問題，船舶不止包含多種不同的構件，同時各構件可能會有不同的破壞模式，因此過去許多學者為了分析船舶撞擊問題，把船舶的破壞型式歸納成幾種基本構件的破壞模式(例如：板或樑的撕裂破壞模式)，然後再利用力學的方法推導出簡化公式以便利用。本文主要探討板受到撞擊時的捲曲撕裂破壞模式及褶皺破壞模式，檢討過去學者針對此類破壞模式的理論基礎與推導簡化公式的方法，重新進行簡化公式之推導。
由於電腦的進步，利用有限元素法分析船舶碰撞問題也愈來愈廣泛。本文把之前所提到的板受撞擊的破壞模型進行有限元素暫態分析，所得之結構作用力與消散能量結果和簡化公式作一比較驗證。
實際的船舶結構含有緃橫交錯的構件，並非單一構件所組成，為了簡化問題，本文把貼在板面上的肋骨材之面積平均分散於板上，並利用板捲曲撕裂破壞模式簡化公式估算。最後本文利用美國Naval Surface Warfare Center (NSWC)所做的擱淺實驗模型進行FEM分析，並比較實驗，簡化公式及FEM計算三者之結果。

關鍵字

褶皺破壞 ； 塑性吸能 ； 半解析估算式 ； 切割破壞 ； FEM ； 擱淺 ； 碰撞

並列摘要

Nowadays, more than 80 % of international cargo still depends on ship transportation. Due to the economic growth, the number of ships is increasing rapidly, at the same time, the ship collision and grounding issues become more and more important. The mechanics of ship collision and grounding are very complex topics and different damage modes may occur simultaneously for a structure. In past decades, the damage modes have been categorized into different simple modes, and the approximated methods have also developed for the simplified modes, e.g. beam and plate. Based on plastic damage mode, the simplified analytical formula for fundamental mechanics of plastic hinge line of the beam and plate simplified analytical formula can be derived for practical use. This thesis focus on the damage status of plate subjected to impact, especially the tearing mode and folding mode. We review some developed formulas and introduced the derivation of simplified analytical formula.
Finite Element Method has been widely used in ship collision and grounding issues. In this paper the LS-DYNA was used to verify the damage model. The calculated results are compared with simplified analytical formula.

並列關鍵字

plastic energy ； tearing ； folding ； grounding ； collision ； FEM ； half analytic approximation

參考文獻

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