冰区海上采油平台极端冰载下断裂的可靠性分析

Fracture Reliability Analysis of Offshore Production Platform on Extreme Heavy Ice-Load in Ice Region

我国渤海每年约有3个多月的结冰期,冰与海上采油平台的相互作用,远较波浪为甚.因此,冰区固定采油平台的设计以及对服役期平台的评估,均需进行可靠性分析,而且主要是极端冰裁作用下断裂的可靠性分析.文章首先建立了考虑温度效应的剩余强度的可靠性计算模型;然后给出了决定构件剩余强度的断裂韧性CTOD值δ_0的不同温度下的概率分布;同时还给出了取决于冰厚及海冰强度的构件上最大应力的概率分布;最后,根据计算模型,文章给出了计算平台构件可靠度的方法,并结合渤海八号平台评估的计算实例,对在役海上采油平台的整体系统,进行了安全可靠性分析.

Every year,there are more than 3-months ice age in China Bohai Sea, with more interaction between ice and offshore production platform than wave and offshore production platform. Therefore, the design of fixed production platform in ice region and the platform's evaluation during the period of service need to have reliability analysis, mainly on fracture reliability analysis with extreme heavy ice-load. First, this article sets up reliability computation modole concerning residual intensity of temperature effect; second, it gives probability distribution in different temperature that decides fracture toughness CTOD value δc for residual strength of component and the probability distribution that depends on maximum stress on constructional element for ice thickness and sea-ice strength; finally, according to computation modole, this article gives the method that calculates the reliability of platform component, combined with computation example for evaluation of Bohai Sea platform 8, making safe reliability analysis for the whole offshore production platform system being on service.