【摘要】：對船體梁的縱向彎曲極限強度的準確評估是船舶結構設計的基本方面,焊接初始缺陷的存在會影響結構的剛度與極限強度。準確預測焊接后的殘余應力與變形對極限強度的研究有重要的意義。本文將熱彈塑性有限元方法與船體結構極限強度數(shù)值方法相結合,更加合理地考慮焊接初始缺陷對于船體結構極限強度的影響。為了進行理想剖面船體結構的極限強度分析本文主要進行了以下工作:(1)利用熱彈塑性有限元法與具有截面積分的shell/solid單元模型進行板架縱骨焊接的溫度場與應力場分析。在此基礎上比較分析了不同邊界條件對焊接變形與殘余應力結果的影響。將板架周圍的結構簡化為加筋板的固定邊界,更合理地反映板架中的縱骨焊接變形情況。(2)以理想艙段結構中的縱骨焊接作為研究對象,考慮結構周圍材料對加筋板焊接模擬的影響,計算由焊接引起的殘余應力和變形初始缺陷。(3)將理想艙段結構離散為加筋板單元與硬角單元,以加筋板單元為研究對象,采用非線性有限元方法進行極限強度分析。將熱彈塑性有限元分析得到的焊接初始缺陷引入極限強度的分析中,比較有無初始缺陷以及不同的焊接分析邊界對結構失效模式與極限強度的影響。得到筋板單元失效后包含后屈曲段的完整平均應力應變關系曲線,進行箱型結構極限強度的逐步破壞法分析。
[Abstract]:The accurate evaluation of longitudinal bending ultimate strength of hull girder is the basic aspect of ship structure design. The existence of initial welding defects will affect the stiffness and ultimate strength of the structure. Accurate prediction of residual stress and deformation after welding is of great significance to the study of ultimate strength. In this paper, the thermal elastoplastic finite element method is combined with the numerical method of the ultimate strength of the hull structure, and the effect of the initial welding defects on the ultimate strength of the hull structure is considered more reasonably. In order to analyze the ultimate strength of the hull structure with ideal section, the main work of this paper is as follows: (1) the thermal elastoplastic finite element method and the shell/solid element model with sectional area are used to analyze the temperature field and stress field of plate frame longitudinal bone welding. On this basis, the effects of different boundary conditions on welding deformation and residual stress are compared and analyzed. The structure around the plate frame is simplified as the fixed boundary of the stiffened plate, and the deformation of longitudinal bone welding in the plate frame is more reasonably reflected. (2) the longitudinal bone welding in the ideal cabin structure is taken as the research object. Considering the influence of materials around the structure on the welding simulation of stiffened plate, the initial defects of residual stress and deformation caused by welding are calculated. (3) the ideal cabin structure is divided into stiffened plate element and hard angle element, and the stiffened plate element is taken as the research object. The nonlinear finite element method is used to analyze the ultimate strength. The initial welding defects obtained by thermoelastic-plastic finite element analysis are introduced into the ultimate strength analysis to compare the influence of the initial defects and different welding analysis boundaries on the failure mode and ultimate strength of the structure. The complete average stress-strain relationship curve of the stiffened plate element including the post-buckling section after failure is obtained. The ultimate strength of the box structure is analyzed by the progressive failure method.
【學位授予單位】：上海交通大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U661.43

【參考文獻】

相關期刊論文 前10條

1 張婧;施興華;顧學康;;具有初始缺陷的船體加筋板結構在復雜受力狀態(tài)下的極限強度研究[J];中國造船;2013年01期

2 馮國慶;周海仲;任慧龍;李曉宇;;焊接初始缺陷對船體梁極限彎矩的影響[J];船舶工程;2011年02期

3 祝金丹;陳虎;鞏建鳴;涂善東;;殼單元應用于薄板多道焊焊接數(shù)值模擬的方法探討[J];焊接學報;2008年11期

4 陳建波;羅宇;龍哲;;大型復雜結構焊接變形熱彈塑性有限元分析[J];焊接學報;2008年04期

5 江克斌;肖葉桃;郭永濤;;T型焊接試件焊接殘余應力分布的測定[J];焊接學報;2008年01期

6 劉建華,王自力,張家新;船舶結構極限強度分析的理想結構單元法[J];工程力學;2005年02期

7 謝雷,羅宇,謝志勇,帥克剛;基于固有應變的大型焊接結構變形的預測[J];焊接學報;2004年02期

8 張錦飛,崔維成;三種船型結構的極限強度分析比較[J];船舶力學;2003年04期

9 張濤,劉土光,趙耀,王先洲;初始缺陷加筋板的屈曲與后屈曲分析[J];船舶力學;2003年01期

10 吳言高,李午申,鄒宏軍,馮靈芝;焊接數(shù)值模擬技術發(fā)展現(xiàn)狀[J];焊接學報;2002年03期

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