【作者】 王荣祥；

【导师】 岳前进；

【作者基本信息】 大连理工大学 ， 计算力学， 2008， 硕士

【摘要】 对渤海冰区多座海洋平台进行现场监测的结果表明,在冰荷载作用下导管架平台存在比较剧烈的振动现象,并直接威胁着平台的安全。本文基于对渤海平台的现场监测数据以及冰荷载研究的最新成果,对冰区导管架海洋平台冰激振动下的疲劳问题进行了详细分析和总结。首先,本文介绍了波浪荷载下海洋平台疲劳问题的研究进展,以及冰区环境条件和冰区海洋结构物的冰激响应研究现状,并提出了本文的研究内容。其次,本文介绍了疲劳研究的基本概念及其主要特点;介绍了疲劳设计的主要方法,其理论依据主要是Miner理论和断裂力学理论,总结了各自特点及其适用范围;总结了波浪荷载下海洋平台疲劳分析的一般性方法,为冰荷载下结构的疲劳分析提供了借鉴。再次,在对渤海现场原型试验和基于现场原型试验取得的冰荷载研究成果过的基础上,对渤海两座典型导管架平台进行了动力响应分析,计算了平台甲板的振动加速度并通过了实测数据的验证,为进一步的导管架管结点处的应力计算做了必要的技术准备。最后,对冰区导管架平台的疲劳问题进行了较全面的分析,并对冰振作用下管结点疲劳寿命的详细计算方法进行了研究。基于海洋平台的动力特性,从定性和定量两个方面说明了冰区导管架平台进行详细疲劳分析的必要性;总结目前冰区海洋结构疲劳分析方法的研究进展并指出需改进的方面,并在此基础上提出基于现场监测的疲劳分析方法;介绍了基于现场监测的疲劳分析方法的详细流程;以JZ20-2MSW平台为实例应用基于现场监测的疲劳分析方法详细计算了该平台管结点的疲劳寿命。更多还原

【Abstract】 It is indicated that the ice-induced vibration of ice-resistant platforms is quite intensive, and directly endangers the structural safety according to the field data monitored on several platforms in the Liaodong Bay of Bohai Sea. A detailed research and summarization on the ice-induced fatigue of jacket platforms in the ice-covered regions is presented based on in situ results of ice-induced vibration and the current progress of ice load.Firstly, this paper gives an introduction of the current progress of platform fatigue under wave load, ice-covered regions environmental condition, and ice-induced respond of offshore structures, and then presents the assignment. Second, this paper gives an introduction of the basic conception and primary fatigue design methods, and summarizes the run-of-mill fatigue analysis method of platform under wave load, which provides use for reference of fatigue analysis of platform under ice load.Third, The dynamic responds of jacket platforms in the Bohai Sea are analyzed, the vibration acceleration of platform deck is computed and compared with the field monitored data based on the full-scale field tests and progress of ice load, which provides preparative for computing the stress of the tube node of the jacket platform.At last, this paper gives a general analysis and a detailed analysis method of the jacket platform in the ice-covered regions. It points out the necessity of analyzing fatigue life of the platform from qualitative and quantitative sides, based on the dynamic characteristics of jacket platforms. It presents fatigue analysis method based on the field monitored data, and gives a detailed flow of this method. For example, fatigue life of tube node of the JZ20-2MSW jacket platform is computed based on this method.更多还原