摘 要
半潛式平臺長期在深海作業(yè)，不可避免地會(huì)遭遇惡劣海況，由風(fēng)、浪和流引起的極值環(huán)境載荷可腀@教ń峁棺畬蟪性嗇芰?，磦蝤造成人员、平台憾dＱ蠡肪車難現(xiàn)廝鶚?，同时平台环境圆G珊統(tǒng)性嗇芰哂忻饗緣乃婊裕虼似攔臘肭筆狡教ń峁拱踩雜諂教耷慷齲捎每煽啃苑椒ń醒芯?。本文以工信部十一五竾`際醮翱蒲邢钅課塵埃捎彌鴆狡蘋搗ㄑ芯堪肭筆狡教耷慷齲⒔岷轄峁箍煽啃約撲愕氖的Ｄ夥?，建立半枪P狡教ㄕ寮耷慷瓤煽啃約撲隳Ｐ?，为半枪P狡教ń峁股杓坪桶踩云攔撈峁┮讕蕁�
本文首先詳細(xì)分析了加筋板格屈曲失效模式，采用梁-柱理論、理性彈塑性假設(shè)和塑性鉸理論研究了加筋板單元的應(yīng)力-應(yīng)變關(guān)系，并給出不同階段加筋板單元應(yīng)力-應(yīng)變計(jì)算公式。
其次，采用簡化方法研究了船體和平臺結(jié)構(gòu)逐步破壞過程，編寫了船體和平臺結(jié)構(gòu)極限強(qiáng)度計(jì)算程序，與箱型梁模型試驗(yàn)和實(shí)船事故比較分析結(jié)果表明本文的計(jì)算程序是正確可靠的，采用該程序研究了目標(biāo)平臺結(jié)構(gòu)整體極限強(qiáng)度，詳細(xì)地分析不同因素對平臺結(jié)構(gòu)極限強(qiáng)度的影響。
最后，采用拉丁超立方抽樣方法結(jié)合條件期望和對偶變數(shù)方差減縮技術(shù)，給出結(jié)構(gòu)可靠性計(jì)算的數(shù)值模擬法，建立半潛式平臺整體極限強(qiáng)度可靠性計(jì)算模型，在目標(biāo)平臺結(jié)構(gòu)可靠性分析的基礎(chǔ)上給出平臺結(jié)構(gòu)目標(biāo)可靠度的建議值。
關(guān)鍵詞：半潛式平臺；屈曲模式；極限強(qiáng)度；簡化方法；結(jié)構(gòu)可靠性；方差減縮技術(shù)








Abstract
Heavy sea state inevitably occurs during long working period of semi-submersible platforms at deep sea. Extreme environmental loads due to wind, wave and current, may exceed maximum load carrying capacity of platform structures which lead to huge loss of persons, platforms and environment. On account of obvious randomness of environmental loads and load carrying capacity of platforms, safety assessment of platform structures should be conducted by reliability method based on ultimate strength of platforms. This thesis is based on 11th five years research projects of high technology ships of industry and information department. The purpose of this thesis is to study ultimate strength of semi-submersible platforms using progressive collapse method, to establish calculation model of overall ultimate strength reliability of semi-submersible platforms using numerical simulation method of structural reliability calculation method, and to provide an important basis of design and safety assessment of semi-submersible platforms.
Firstly, buckling mode of stiffened plate is analyzed in detail. Stress-strain relationship of stiffened plate elements is studied using beam-column theory, idealized elastic-plastic assumptions and plastic joint theory. Calculation formulas of stress-strain relationship of stiffened plate elements at different stages are also given.
Secondly, progressive collapse course of ship and platform structures is studied using simplified method. Calculation program of ultimate strength of ship and platform structures is compiled and comparative analysis results of box girder model test and ship accident show this program is true and reliable. Overall ultimate strength of target platform is studied using this program and effect of different factors to ultimate strength of platform structures is also analyzed.
Finally, numerical simulation method of structural reliability calculation is given using Latin hypercube sampling with variance reduction techniques of conditional expectation and antithetic variates. Calculation model of overall ultimate strength reliability of semi-submersible platforms is established and target reliability index is suggested based on structural reliability analysis of target platform.
Key words: semi-submersible platform; buckling mode; ultimate strength; simplified method; structural reliability; variance reduction techniques


目錄
摘要 I
Abstract III
第1章 緒論 1
1.1 論文研究的目的和意義 1
1.2 國內(nèi)外研究現(xiàn)狀 2
1.2.1 平臺環(huán)境載荷研究 2
1.2.2 平臺結(jié)構(gòu)極限強(qiáng)度研究 3
1.2.3 平臺結(jié)構(gòu)可靠性研究 4
1.3本文研究內(nèi)容和創(chuàng)新點(diǎn) 6
第2章 半潛平臺加筋板單元應(yīng)力-應(yīng)變關(guān)系研究 9
2.1引言 9
2.2 半潛平臺加筋板單元屈曲失效模式 9
2.2.1 加強(qiáng)筋翼緣失效 9
2.2.2 帶板破壞 11
2.2.3 加強(qiáng)筋和板的組合失效 12
2.3 半潛平臺加筋板單元應(yīng)力-應(yīng)變關(guān)系 14
2.3.1 角單元和受拉單元 15
2.3.2 受壓單元 15
2.4 算例分析 17
2.4.1 單元?jiǎng)澐?17
2.4.2 單元應(yīng)力-應(yīng)變關(guān)系 18
2.5 小結(jié) 21
第3章 半潛平臺整體極限強(qiáng)度研究 23
3.1 引言 23
3.2半潛平臺整體彎矩曲率的增量計(jì)算方法 23
3.3 模型試驗(yàn)和實(shí)船強(qiáng)度比較分析 24
3.3.1 Reckling模型 24
3.3.2 Dowling模型 27
3.3.3 VLCC 29
3.4 半潛平臺整體極限強(qiáng)度算例分析 32
3.4.1平臺單元?jiǎng)澐?33
3.4.2目標(biāo)平臺彎矩－曲率關(guān)系 33
3.5半潛式平臺結(jié)構(gòu)強(qiáng)度影響參數(shù)分析 34
3.5.1材料對彎矩的影響 34
3.5.2焊接殘余應(yīng)力的影響 39
3.5.3橫向壓力的影響 40
3.5.4加筋板單元載荷—縮短行為的影響 40
3.5.5腐蝕的影響 43
3.6小結(jié) 45
第4章 半潛式平臺整體可靠性研究 47
4.1引言 47
4.2結(jié)構(gòu)可靠性計(jì)算方法 47
4.2.1 直接積分法 47
4.2.2改進(jìn)的一階二次矩 49
4.2.3 數(shù)值模擬法 50
4.3平臺整體可靠性計(jì)算 60
4.3.1平臺載荷的統(tǒng)計(jì)特征 60
4.3.2 結(jié)構(gòu)能力的統(tǒng)計(jì)特征 62
4.4.3可靠性計(jì)算 63
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