90m自升式平台结构强度及疲劳分析

发布时间：2018-03-21 06:58

本文选题：90m自升式平台　切入点：结构强度　出处：《浙江海洋学院》2014年硕士论文　论文类型：学位论文

【摘要】：自升式平台是海洋油气勘探、开发的主要设备，它在海洋石油开发过程中发挥着重要的作用。平台长期处于恶劣海况下，由于风、浪、流等环境载荷对其的作用在很大程度上影响着平台的作业安全，因此对自升式平台进行结构强度分析显得尤为必要。此外，由于自升式平台的桩腿结构长期受波浪作用会使其内部产生交变应力，，进而导致桩腿发生疲劳损伤，因此对其进行疲劳寿命分析也是不可或缺的。针对这些问题，本文主要进行以下研究：首先，基于莫里森公式和Stokes五阶波理论，采用MATLAB编写程序，计算了桩腿在自存与作业两个工况下的波浪力。其次，基于正在建造的90m自升式平台，根据中国船级社《海上移动平台入级与建造规范》，采用有限元软件Patran/Nastran建立有限元模型；综合考虑风、浪、流等载荷的不同组合，对自升式平台在自存、作业两个典型工况下进行结构强度计算和模态分析，并对其进行强度校核。最后，采用GeinE建立疲劳分析的平台简化模型，利用Wajac进行水动力分析，然后基于Framework对平台在作业工况下进行了桩腿的疲劳分析。考虑到平台的应力集中效应，采用确定性设计波法，计算在波浪循环作用下桩腿结构的累积损伤，进行疲劳寿命研究。研究表明，自升式平台现有的结构形式可以满足其在恶劣海况下自存并钻井作业，平台易于波浪低频成分发生共振。疲劳寿命分析结果表明，受波浪影响，后右桩腿与海平面接触区域管节点的疲劳寿命最短，对这些区域的管节点强度应足够重视。
[Abstract]:Jack up platform is the main equipment of offshore oil and gas exploration, development, it plays an important role in the process of offshore oil development platform. In the long-term adverse conditions, due to wind, wave, flow and other environmental loads on its effect has a great influence on the safety operation platform, so the self lifting platform structural strength analysis is necessary. In addition, due to the legs of the jack up platform by long wave action will make its internal alternating stress, which can lead to fatigue damage of the leg, is also indispensable because of fatigue life analysis. To solve these problems, this paper mainly carried out the following research:
First, based on the Morrison formula and the Stokes five order wave theory, the wave force of the pile leg under two conditions of self storage and operation is calculated by using MATLAB programming.
Secondly, the jack up platform is built based on 90m, according to Chinese CCS < offshore mobile platform into the specification and construction, finite element model is established by finite element software Patran/Nastran; considering the wind, waves, different combinations of load flow, the jack up platform in self storage, calculation and analysis of structural strength two typical working modes, and its strength check.
Finally, using GeinE to establish the fatigue analysis platform simplified model, hydrodynamic analysis by Wajac, and then based on Framework on the platform for the analysis of fatigue of piles in working conditions. Considering the platform stress concentration effect, the deterministic design wave method in the calculation of cumulative damage under the action of wave cyclic leg structure. Research on fatigue life.
The research shows that it can satisfy the in adverse conditions from drilling and self lifting type structure of the existing platform, the platform is easy to low frequency wave resonance. The fatigue life analysis results show that affected by wave, after the sea level right leg and pile contact area of tubular joints fatigue life of tubular joints of the shortest. These areas should be paid more attention.

【学位授予单位】：浙江海洋学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P752

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