半潜式平台结构疲劳特征研究

Structure fatigue characteristics for semi-submersible platform

本文研究2种典型结构形式半潜平台在不同海域结构应力长期分布特征。对比中国南海典型波浪散布与墨西哥湾典型波浪散布特征,计算两海域平台结构应力响应,得到平台结构应力范围长期Weibull分布形状参数。中国南海典型环境条件对于双下浮体式半潜平台结构波浪应力长期Weibull分布形状参数不大于1,对于环形浮箱半潜平台结构波浪应力长期Weibull分布形状参数不大于1.05,为针对中国南海应用简化疲劳分析方法分析半潜式平台结构疲劳寿命提供依据。同时,计算得到两类典型半潜式平台在墨西哥湾典型环境条件下结构波浪应力长期Weibull分布形状参数值不大于0.8的结论,证实对于半潜式平台的疲劳设计,南海疲劳海况较墨西哥湾海况更恶劣。

This paper focus on the long term stress distribution characteristics of two typical semi submersible platform in different sea areas.The typical wave scatter in the South China Sea and the Mexico Gulf are compared.The stress response of the two typical platform structures is calculated,and the long-term Weibull distribution shape parameters of the structure stress range are obtained.For the typical environmental conditions of the South China Sea,the shape parameters of the long-term Weibull distribution for the double pontoon semi submersible platform are not greater than 1,and for the ring pontoon semi submersible platform,the wave stress Weibull shape parameter is not greater than 1.05.This paper provides a basis for the fatigue analysis of semi submersible platform structure by using simplified fatigue analysis method in the South China Sea.At the same time,the two typical semi submersible platform stress long-term shape parameter of Weibull distribution for typical conditions of Mexico Gulf is not greater than 0.8,it confirmed that the China South Sea condition is worse than in the Gulf of Mexico sea for fatigue design of semi submersible platform.