海洋延寿平台随机冰激响应与损伤评估

直立结构上冰力作用是国际海洋石油工程界研究的一个热点,尽管很多学者建立了各种冰力破碎模型,但是这些理论模型实现对冰与直立结构交互作用过程的量化模拟还存有较多困难.针对胜利油田大量海上平台超期服役现状,选择渤海现场实测的随机冰力时程曲线,考虑腐蚀减薄、桩基冲刷、海生物附着等服役损伤,建立海洋延寿平台结构有限元模型,研究随机冰力作用下海洋延寿平台构件的时程响应,采用疲劳等效应力幅来描述随机冰激疲劳应力过程产生的疲劳效应,最后基于Miner线性累积疲劳损伤模型采用S-N曲线法评估平台构件的疲劳损伤,该方法为进行可适合工程应用的渤海延寿平台疲劳评估提供了思路.

Stochastic Ice-induced response and structure damage of the life-expanded offshore platform

Ice Force on vertical structure is a hot spot in the field of international offshore oil engineering.Although many scholars have established various models for ice force crushing,however there are still many difficulties for these theoretical models to realize the quantitative simulation of the interaction between ice and the vertical structure.In respect of the current situation that a large number of offshore platforms in Shengli Oil Field extend service,choosing the time-histories curve of random ice force actually measured on the site of the Bohai Sea,and considering the service damages such as corrosion reduction,scour around pile foundation and adhesion of living beings etc.,the finite element model for the structure of the life-expanded offshore platform was established to study the response of the time histories for the constructional element of the structure of the life-expanded offshore platform.In this paper,the equivalent stress of fatigue was adopted to describe the fatigue effect incurred in the course of random ice-induced fatigue stress.Finally,based on Miner linear accumulated fatigue damage model,S-N curve method was adopted to assess the fatigue damage of the constructional elements of the offshore platform.This method provides a train of thought for the assessment of life-expanded offshore platform appropriate to engineering application in the Bohai Sea.