【作者】 柯军；

【导师】 严仁军；

【作者基本信息】 武汉理工大学 ， 船舶与海洋结构物设计制造， 2014， 硕士

【摘要】 海洋平台在服役当中经常需要进行强度评估来确保平台的安全运营，其中，腐蚀是造成海洋平台受损的影响因素之一，造成海洋平台强度下降的不利影响，甚至引起海洋平台发生破坏，导致安全事故，从而造成极大的经济损失。所以，对腐蚀进行研究，考虑它对海洋平台极限强度的影响，进而安全评估受损海洋平台的极限强度具有重大的现实意义和工程意义。首先，本文介绍了常用的裂纹损伤构件的极限强度评估方法，将这些方法的评估结果与实验值进行比较，结果显示：在裂纹较小时，有限元方法更合理、可靠。最终选取有限元方法研究海洋平台腐蚀损伤问题。其次，利用ANSYS有限元软件分析不同的腐蚀损伤凹坑几何参数对圆管构件的极限强度的影响，并总结出相应的几何参数的影响规律，在此基础上通过非线性回归方法，得出凹坑损伤圆管的极限强度经验公式，并以此公式求得受损构件极限强度系数以便评估整个平台的极限强度。最后，利用ANSYS有限元软件建立完整海洋平台的实体模型，通过本文中的经验公式和强度等效原则修改平台受损导管的尺寸，模拟损伤，进而对海洋平台的极限强度进行评估，分析腐蚀损伤的规律，同时，讨论海洋平台桩腿受损程度对极限强度的影响。经过研究表明，腐蚀损伤对海洋平台产生的不可忽视的影响，在工程应用中应该得到足够的重视，并及时做好防护措施。更多还原

【Abstract】 It is often necessary to assess the strength of offshore platform to ensure itsoperation safety. During its service period, numerous factors, such as corrosion, mayhave negative effect on its structural strength, which can lead to serious accident andcause great economic losses. Therefore, it is significant to assess the ultimate strengthof damaged offshore platform by studying corrosion and its impact on the ultimatestrength.Firstly, this paper provides an overview of the ultimate strength crack damageassessment methods, and their results were analyzed to verify the rationality andreliability of the finite element method, which will provide basis for the corrosiondamage research.Secondly, the finite element software ANSYS was used to analyze the effect ofdifferent corrosion damage pits on the ultimate strength of tube member, andsummarizes the corresponding influence of different geometrical parameters. Anempirical formula was developed to assess the ultimate strength of tube member withpit injury, thus the damaged components’ ultimate strength coefficients can beobtained to assess the ultimate strength of the entire platform.Finally, a complete physical model of offshore platforms was built in ANSYS,and the dimension of the damaged pipe was modified using the above empiricalformula and strength equivalent principle. After the damage simulation, we can assessultimate strength of offshore platform and analyze the regulation of corrosion damage.Meanwhile, we can also discuss the impact of damaged legs on the ultimate strength.The study shows that corrosion damage has an assignable impact on the marineplatform, which should be given adequate attention in engineering applications, thusprotection measures should be taken in a timely manner.更多还原