【作者】 付敏飞；

【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， 2007， 硕士

【摘要】 海洋平台结构在服役期间承受要十分复杂的载荷，自升式平台的升降装置既需要在升降状态下完成桩腿及甲板的升降，又需要在正常工作状态和风暴自存状态下支撑船体甲板及相关设备，往往承受着高频率的交变载荷。固桩架是自升式平台升降系统的一个重要组成部分，固桩架作为连接桩腿与平台主体的主要结构，在自升式海洋平台的各种作业状态下均起到传递荷载的作用，所以升降装置中固桩架出现疲劳失效的可能性较大，必须对该结构进行疲劳强度校核。首先，建立胜利作业3号平台整体空间板梁组合结构有限元分析模型，并对其在极端波浪条件下进行了静力分析，根据结构强度和规范要求校核平台主船体结构的静强度。然后对平台进行了模态分析和动力响应分析，通过模态分析可以得出平台的自振特性；通过平台的动力响应分析可以得到平台固桩架的应力—时间响应，从而确定固桩架的危险点，以及危险点的应力—时间响应历程。最后，在平台进行动力分析的基础上，通过对平台升降装置上危险点的动力响应结果的分析和处理，采用P-S-N曲线方法和线性累积损伤理论计算平台固桩架的疲劳损伤，并评估固桩架的疲劳寿命，从而估算平台的疲劳寿命。在疲劳计算中，运用峰值计数法对应力循环进行记数和Goodman等寿命曲线对非等幅应力循环进行修正，所得出的计算结果对平台的寿命的估算有一定的指导意义。更多还原

【Abstract】 Ocean platform must withstand extremely complex load in service period, often withstands the high-frequency alternating load, but the elevating gear already needs to complete the spud leg and the deck fluctuation under the fluctuation condition, and also needs sustaining hull deck and equipment in the normal work condition and the storm. The Shelf of fixup-leg is a important constituent of jack-up platform jacking system. Shelf of fixup-leg took the connection spud leg and the platform main body main structure, moves the platform in the jack up under each kind of work condition to play the transmission load role. So there is more possibility that shelf of fixup-leg appears to be fatigue failure. Failure analysis of shelf of fixup-leg is very necessary.First, integral special shell-beam element model of shengli3 is set up, which has been carried on the static analysis to it under the extreme wave condition. Besides , static strength of the platform host hull structure and the spud leg are checked according to the structural strength and the standard.Then, the platform has been carried on the modality analysis and the dynamic response analysis. Through the modality analysis we can see oscillation characteristic of the platform; also we can get stress-time response of shelf of fixup-leg through the platform dynamic response analysis. Thus we can determination hazard point, as well as stress-time response of hazard point.Finally, through analysis and disposed of stress-time response of hazard point of shelf of fixup-leg , used the P-S-N curve method and the linearity cumulative damage theory has carried on the computation to the platform structure fatigue damage, and appraised platform structure fatigue life. The method and computed result has certain guiding sense to the platform life estimate.更多还原