海洋立管浪致疲劳损伤及其对结构疲劳寿命的影响

Wave-induced Fatigue Damage of Marine Riser and Its Effect on Structural Fatigue Life

波浪是导致浅海平台立管疲劳失效的主要因素。针对渤海湾某海域特征波浪作用下海洋立管的疲劳损伤进行了时域分析,利用ANSYS软件对立管进行静力和瞬态动力学分析,获取特征波浪作用下海洋立管的疲劳危险位置,分析管卡约束形式、弯管半径、管卡分布形式对立管疲劳寿命的影响,并设计一套管卡最优排布方式。结果表明:立管疲劳危险点出现在弯管底部;管卡约束形式对结构疲劳寿命影响不大;减小弯管半径有助于提高结构疲劳寿命;增大管卡排布间距有助于提高立管疲劳寿命。分析结果可为海洋立管结构的工程防护提供参考。

Wave is the main factor leading to the fatigue failure of risers in shallow sea platforms.A time domain analysis was carried out for the fatigue damage of the marine riser under the action of characteristic waves in a certain sea area of Bohai Bay.The static and transient dynamic analysis of the riser was carried out by using ANSYS software,and the fatigue risk position of the marine riser under the action of characteristic waves was obtained.The influence of clamp constraint form,elbow radius and clamp distribution form on the fatigue life of riser was analyzed,and an optimal arrangement of tube clips was designed.The results show that the fatigue risk point of the riser appears at the bottom of the elbow;the restraint form of clamps has little effect on the fatigue life of the structure;reducing the elbow radius helps to improve the fatigue life of the structure;and increasing the spacing of clamps helps to improve the fatigue life of the riser.The analysis results can provide a reference for the engineering protection of the marine riser structure.