海洋漂浮管道弯曲失效有限元分析

Finite element analysis on bending failure of offshore floating pipeline

海洋漂浮管道受弯曲荷载作用时,可能发生较大弯曲进而导致管道失效,威胁海上油田原油输送安全。针对管道帘线层与螺旋钢丝失效机理不明确的问题,考虑管道弯曲时螺旋钢丝扭转行为,建立漂浮管道三维有限元模型,并通过实例管道验证了数值模型的有效性,进而利用该有限元模型模拟管道弯曲失效过程并分析管道结构参数对最小弯曲半径的影响。结果表明:海洋漂浮管道弯曲失效以螺旋钢丝屈曲为失效模式,未发生帘线强度失效;管道最小弯曲半径随帘线层铺层层数与螺旋钢丝直径的增大而增大,但随帘线纤维缠绕角度的减小而增大。所建立的有限元模型有效模拟了漂浮管道弯曲行为,可为海洋漂浮管道结构设计与安全应用提供理论参考。(图11,表5,参26)

Large bending may occur to the offshore floating pipeline under the action of bending load,which further results in the pipeline failure,threatening the transportation safety of crude oil from the offshore oil field.As the failure mechanism of the cord layer and spiral steel wire of pipeline is not clarified,a three-dimensional finite element model of floating pipeline was established with consideration to the torsional behavior of spiral steel wire during pipeline bending,and the validity of the numerical model was verified by bending experiments of example pipelines.The process of bending failure of pipeline was simulated with the finite element model,and the influence of pipeline structure parameters on the minimum bending radius was analyzed.The bending failure of the pipeline is in the mode of spiral steel wire buckling,without strength failure of cord.In addition,the minimum bending radius of pipeline will increase with the increasing of the number of cord layers and the diameter of spiral steel wire or the decreasing of the winding angle of the cord fiber.In general,the results show that the finite element model can effectively simulate the bending behavior of the floating pipelines,which can provide theoretical reference for the structural design and safety application of offshore floating pipelines.(11 Figures,5 Tables,26 References)