本文關(guān)鍵詞： 海洋柔性立管 抗疲勞設(shè)計(jì) 疲勞壽命 非線性彎曲響應(yīng) 有限元　出處：《大連理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：海洋柔性管道是連接浮式平臺(tái)與海底井口進(jìn)行深海油氣開(kāi)發(fā)的關(guān)鍵裝備。在周期性交變載荷作用下,柔性立管的金屬鎧裝層容易發(fā)生疲勞破壞,導(dǎo)致災(zāi)難性后果。由于金屬鎧裝層間的接觸摩擦,其彎曲響應(yīng)往往呈現(xiàn)明顯的非線性特征,使得其疲勞壽命設(shè)計(jì)與分析存在問(wèn)題。柔性立管的疲勞壽命是其抗疲勞性能的核心衡量指標(biāo),直接決定了深水柔性立管在位運(yùn)行的安全可靠性。柔性立管的抗疲勞設(shè)計(jì)是以其疲勞壽命分析為基礎(chǔ),提出以安全壽命設(shè)計(jì)準(zhǔn)則和S-N曲線法為基礎(chǔ)的柔性立管疲勞壽命預(yù)測(cè)模型與流程。為了更好的設(shè)計(jì)立管結(jié)構(gòu),使其具有更長(zhǎng)的服役壽命,其中關(guān)鍵力學(xué)問(wèn)題研究包括：由于柔性立管復(fù)雜的結(jié)構(gòu)和環(huán)境,其非線性彎曲剛度無(wú)法應(yīng)用經(jīng)典的梁理論模型予以刻畫(huà)。分別建立預(yù)測(cè)柔性立管非線性彎曲剛度的數(shù)值模型和解析模型,通過(guò)與彎曲剛度測(cè)試值對(duì)比驗(yàn)證數(shù)值模擬模型的準(zhǔn)確性�；跀�(shù)值模型預(yù)測(cè)結(jié)果,考慮彎矩與曲率的非線性關(guān)系,建立疲勞載荷分析模型。針對(duì)當(dāng)前關(guān)于彎曲應(yīng)力解析模型的局限性,建立單根螺旋鋼絲纏繞圓柱內(nèi)核的力學(xué)模型,計(jì)算特定曲率下鋼絲局部應(yīng)力；對(duì)比公開(kāi)發(fā)表的三大類7種解析模型,將解析模型預(yù)測(cè)結(jié)果與數(shù)值預(yù)測(cè)結(jié)果比較,確定解析模型的適用性。同時(shí),討論了鋼絲的寬高比和螺旋角對(duì)解析模型適用性的影響。本文依托國(guó)家“十二五”863項(xiàng)目“柔性海底管道關(guān)鍵技術(shù),究”專題,以1500米水深的8寸內(nèi)徑柔性立管為例,對(duì)其疲勞壽命進(jìn)行計(jì)算�？紤]影響海洋柔性管道疲勞強(qiáng)度的主要因素,提出了進(jìn)行疲勞校核時(shí)依據(jù)的S-N曲線模型；著重考慮了各種非線性因素和平均應(yīng)力對(duì)疲勞壽命預(yù)測(cè)的影響。以上研究工作對(duì)我國(guó)深海立管的設(shè)計(jì)提供一定的理論基礎(chǔ)和數(shù)值分析方法。
[Abstract]:The offshore flexible pipeline is the key equipment to connect the floating platform with the submarine wellhead for deep-sea oil and gas development. Under the cyclic alternating load, the metal armour layer of the flexible riser is prone to fatigue damage. Because of the contact friction between the metal armour layers, the bending response of the metal sheathed layer often shows obvious nonlinear characteristics, The fatigue life of flexible riser is the key index of fatigue resistance. The safety and reliability of deep water flexible riser are directly determined. The fatigue resistance design of the flexible riser is based on the analysis of its fatigue life. Based on the safety life design criterion and S-N curve method, the fatigue life prediction model and flow chart of flexible riser are proposed. In order to better design riser structure and make it have longer service life, The key mechanical problems include: because of the complicated structure and environment of flexible riser, The nonlinear bending stiffness can not be described by the classical beam theory model. The numerical model and the analytical model for predicting the nonlinear bending stiffness of flexible riser are established. The accuracy of the numerical simulation model is verified by comparing with the measured results of bending stiffness. Based on the prediction results of the numerical model, the nonlinear relationship between bending moment and curvature is considered. Aiming at the limitation of the present analytical model of bending stress, the mechanical model of single spiral steel wire winding cylindrical core is established to calculate the local stress of steel wire with specific curvature. The applicability of the analytical model is determined by comparing the prediction results of the analytical model with the numerical prediction results of the three categories and seven analytical models published in the paper. The influence of the ratio of width to height and the helix angle of steel wire on the applicability of the analytical model is discussed. Based on the national "12th Five-Year" 863 project "key technology of flexible submarine pipeline, research", the paper takes the 8 inch flexible riser with 1500m water depth as an example. The fatigue life of the pipeline is calculated. Considering the main factors affecting the fatigue strength of marine flexible pipeline, the S-N curve model based on which the fatigue checking is carried out is put forward. The effects of various nonlinear factors and average stresses on fatigue life prediction are emphatically considered. The above work provides a theoretical basis and numerical analysis method for the design of deep-sea risers in China.
【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TE95

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相關(guān)期刊論文 前1條

1 姜豪;楊和振;劉昊;;深海非粘結(jié)柔性立管簡(jiǎn)化模型數(shù)值分析及實(shí)驗(yàn)研究[J];中國(guó)艦船研究;2013年01期

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本文編號(hào)：1526382