【作者】 陈祉宏；

【导师】 徐龙军；

【作者基本信息】 哈尔滨工业大学 ， 建筑与土木工程， 2011， 硕士

【摘要】 近几年,我国开始大力发展海上风电工程。支承结构是海上风电工程中的重要组成部分。单立柱结构是海上风电工程中最常用的结构之一,但是在我国还没有得到具体应用。本文对单立柱支承结构在我国使用的可行性做了初步的探讨,计算分析了此结构的可靠指标,希望能为今后的研究提供一些有价值的信息。针对极值风浪荷载之间的相关性,提出了一种基于Nataf变换的相关非高斯分布随机数算法,并通过数值模拟和实际风浪组合荷载效应的计算,验证了方法的有效性。讨论了基于独立风浪的荷载效应和基于相关风浪的荷载效应的极值之间的关系。对不同的风浪组合荷载效应的拟合方法进行评定,证明了最小二乘法比矩法更精确。应用Archimedean Copula函数构造风浪联合概率分布,并对函数进行检验,认为Gumbel函数最适合描述涠洲岛风浪特性,并得出了χ2检验优于其他检验方法的结论。对经常在工程中应用的重现期和基于Archimedean Copula函数C-测度(C-measure)的第二重现期(Secondary Return Period)进行了理论分析,经实际数据证明,第二重现期定义严格,计算结果更接近荷载效应重现期。针对于海上风电工程单立柱支承结构的特点,对体系可靠度计算方法进行了探讨,分析了几种常用方法的优缺点。结合有限元分析软件ANSYS与科学计算软件MATLAB,采用响应面方法构造极限状态函数,将改进一次可靠度方法应用到求解可靠指标中,建立了以响应面方法为核心的一套完整可行的体系可靠度计算方法。基于平稳二项随机过程,建立地震、风、浪、海流的分布函数,参考挪威船级社规范,结合JCSS荷载组合方法,考虑不同的极限状态函数,计算了海上风电工程单立柱支承结构的可靠指标与失效概率。分析随机变量的灵敏度,对结构可靠度有重要影响的随机变量进行了探讨。研究了风浪相关性对结构可靠度的影响,并分析了原因。更多还原

【Abstract】 In recent years, China began to develop offshore wind power project. Supporting structure is a major component of offshore wind power project. Monopile structure is one of the most common offshore wind power project, but has not been specific applied in our country. In this paper, preliminary study feasibility of the support structure used in our country, calculate and analyze the reliability index of this structure, hoping for future research to provide some valuable information.For the correlation between extreme wind and waves loads, a random sampling method based on Nataf transformation of the correlative non-Gaussian distributions is proposed. Applying this method the correlation of extreme values between mutually independent load effects and correlative load effects is dicussed. Through numerical simulation and actual load effect calculation, verified the validity of the method. Different fitting methods for wind and wave load effects are evaluated, and least square method is proved more suitable than the moment method.Application of Archimedean Copula functions to construct the joint probability distribution of wind and waves, the Gumbel function is considered to be best for Weizhou Islands by different test methods, andχ2 test is the most efficient test method of all. Shortcomings of several common return periods are analyzed. Secondary Return Period is constructed by the Archimedean Copula-based C-measure, the definition of which is stringent, the result of which is closer to the return of load effects Period by theoretical analysis and data analysis.Several system reliability methods are discussed for the mono pile supporting structure of offshore wind power project. With finite element analysis software ANSYS and scientific computing software MATLAB, using response surface method and advanced first order reliablility method to solve the structural system reliability index, and a complete feasible structural system reliability method is established. Base on stationary binomial random process, establishing earthquake, wind, waves and currents distribution functions, referring to DNV specification, using JCSS load combination method, considerring the different limit state functions, calculate the reliability index of the supporting structure. Sensitivity of random variables is analysised and random variables having a major impact on structural reliability are discussed. The effect of the correlation between wind and waves on the reliability index is studied.更多还原