复杂载荷作用下立管触地段损伤管道极限内压承载力的数值分析

Numerical Examination of Ultimate Internal Pressure of Damaged Pipeline in Touchdown Zone under Complicated Loadings

触地段(TDZ)为在役钢悬链线立管(SCR)的关键部位之一,由于环境侵蚀和载荷作用可能形成损伤缺陷。利用有限单元法建立管—土相互作用的三维有限元分析模型,并基于ABAQUS有限元软件数值分析了体积损伤位置因素及提升端位移载荷、环境外压等载荷因素对损伤管道极限内压承载力的影响。结果表明,当体积损伤分布于TDZ管道不同的环向位置和轴向位置时,其极限内压呈一定的变化规律;当管道所受提升端位移载荷增加时,管道的极限内压逐渐降低;而环境外压对管道的极限内压承载力影响较大,管道所受的环境外压越大,其极限内压承载力越高。

The touchdown zone(TDZ)is one of the most important parts of the steel catenary riser(SCR).Due to environment erosion and complicated loadings,defect is easily generated.This Finite element method was used to establish three-dimensional computational model considering the pipe-soil interaction.The ultimate internal pressure of TDZ with damage was calculated by using the software ABAQUS.Volume defect on the different positions with different scales of working loadings and environmental loadings are also discussed.Simulation results show that when volume defect distributes in different circumferential and axial location,ultimate internal pressure of pipeline changes according to certain law.The ultimate internal pressure of the pipeline is decreased with the uplifting load on the lifting end.While the external pressure affects the result greatly;the higher external pressure is,the higher ultimate internal pressure is.