钢悬链线立管静力及波激疲劳分析.pdf

大连理工大学硕十学位论文摘要海底管道的立管段结构是连接平台和海底管道或者井口的主要结构,所处外部环境相当复杂,一直是石油工程领域研究的热点。目前国内对浅海立管的理论研究己相对成熟,但对深海立管的研究尚处于起步阶段。深海立管主要受到波浪、海流、风载等环境载荷作用,同时还受到浮式平台运动的影响。这些载荷往往会造成立管及其它位置上管道的振动问题进而引发管道疲劳损伤等问题。本文首先主要做为基础介绍了近海结构水动力学中最基本的波浪理论,讨论了线性波浪理论和斯托克斯波浪理论的基本方程及其推导,介绍了海洋工程结构物中作用在直立柱体上的波浪力的计算方法。在计算波浪载荷时,介绍了Morison公式以及波浪理论的选取和曳力系数和惯性系数的确定。介绍海流载荷的计算及在海流对波浪力的影响下波浪力的计算方法。然后采用ANSYS软件首先对悬链线立管节点进行静力分析,主要考虑立管在不同的漂移工作环境下,是否满足静力校核要求。其次对立管进行了模态分析,可以得知悬链线振动的特性。又对立管进行谐响应分析,。最后基于Palmgren—Miner累积损伤准则,采用FORTRAN自编程序,计算SPAR 平台横荡和垂荡的情况下,立管不同单元疲劳累积损伤率,从而预测立管疲劳寿命。另外,对于不同有义波高和特征周期的海浪情况,在SPAR横荡作用下,计算立管疲劳累积损伤率。关键词:波浪载荷;海流载荷;静力分析;模态分析;波激疲劳损伤;疲劳寿命钢悬链线立管模态及波激疲劳分析 StaticandWave Induced Fatigue Analysis ofSteelCatenary Riser Abstract Marine riseris themain connector between aplatform and themouth of awell inthe works intough environment and itsanalysis isalways thehottopic inoffshore oil far,the research on shallow—water risers e ,the One On deep-water risersisjust begun wim apreliminary loadings on deep—water riserinclude:wave,current,wind and themovement oftheplatform whiellsometimes bring thevibration ofthe riserinduced tothefatiguedamage problem. As the design basis,the WaVe theory inthehydrodynamic isintroduced inthispaper the equations ofairy wave and stokes wave are advanced and calculation methodology ofthe vertical riser’swave Morison equation whiell governs theanalysis ofthe wave loading,the theory thathow tochoose thewave theory,drag coefficient,inertia coefficient,putation methods ofthewave loading which influenced by both WaVe and mended. Then,the staticanalysis ofthe SCR isimplemented by the finiteelement software ANSYS,which judges whether therisermeets thestrength requirement indifferent drifts. Subsequently,the vibration characteristic and the stress fi'equency response function ale got by themodal andtheharmonic analysis ofthe riser. At last,thefatigue damage per year oftheriserwhen t