复杂载荷下加载路径对管道屈曲压溃影响的研究  

Investigation of the Effect of Loading Path on Pipe Buckling Mechanism Under Complex Loads

作　　者：余建星[1,2] 韩梦雪 余杨 陈海成[1,2] 杨政龙 许伟澎 徐盛博[1,2] 刘泽生 Yu Jianxing;Han Mengxue;Yu Yang;Chen Haicheng;Yang Zhenglong;Xu Weipeng;Xu Shengbo;Liu Zesheng(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China;Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration,Shanghai 200240,China)

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300072 [2]高新船舶与深海开发装备协同创新中心,上海200240

出　　处：《天津大学学报（自然科学与工程技术版）》2021年第10期1017-1024,共8页Journal of Tianjin University：Science and Technology

基　　金：国家科技重大专项资助项目(2016ZX05028005-004);国家自然科学基金资助项目(51879189);国家重点研发计划资助项目(2018YFC0310502).

摘　　要：管道在铺设过程中主要受到轴力、弯矩和水压的联合作用.不同的铺设条件下,管道所受的主导载荷存在不同的组合形式.与此同时,管道在安装、服役和维修期间存在不同载荷施加顺序的问题.针对水压-轴力复合加载和水压-循环弯矩复合加载两种联合加载形式,开展了5组缩尺比管道试验,在上述两种复杂加载情况下,探究不同加载路径对管道屈曲压溃的影响趋势.依托大型商业有限元软件ABAQUS,对试验管件的几何尺寸、受力状态和边界约束条件进行仿真模拟,跟踪管件在不同加载路径下的变形历程和应力分布状态,并对试验结果发现的影响规律进行补充验证.从几何缺陷方面对不同加载路径的影响机理进行探索与挖掘,通过提取管道屈曲压溃截面的椭圆度变化历程,解释了不同加载路径对管道屈曲压溃的影响机理.结果表明:先水压后轴力的加载路径比先轴力后水压的加载路径更危险,先水压后循环弯矩的加载路径比先循环弯矩后水压的加载路径更加危险.当外部先施加水压载荷,相较于轴力的影响效果,弯矩对管道的外压承载力影响更为明显.通过对有限元模型进行后处理分析,发现先水压后轴力和先水压后循环弯矩的加载路径下,水压的存在会加剧后续管道截面椭圆度的增长速率,进而增大管道失效时的截面缺陷,降低管道的极限承载力.The pipeline is primarily affected by axial force,bending moment,and water pressure in the installation process.Under different laying conditions,there are different combinations of dominant loads on pipelines.At the same time,there is the problem of different loading sequences during the installation,service,and maintenance of the pipeline.Because of the two combined loading forms of water pressure-axial force and water pressure-cyclic bending,five groups of scaled pipeline tests were conducted to verify the influence trend of different loading paths on the buckling mechanism of pipes under the two loading conditions mentioned previously.Using the finite element soft-ware ABAQUS,the geometric dimensions,stress states,and boundary constraints of the test pipe were simulated.The deformation history and stress distribution were analyzed.The regulations obtained from the experimental results were supplemented and verified.The influence mechanism of different loading paths was explored from the aspect of geometric defection,which was explained by extracting the change history of the ovality of the collapse section.The results showed that the loading path of water pressure followed by axial force was more dangerous than that of axial force followed by water pressure,and the loading path of water pressure followed by cyclic bending moment was more dangerous than that of cyclic bending moment followed by water pressure.When the external water pressure load is applied first,the bending moment has more obvious influence on the external pressure bearing capacity than the axial force.The results of geometric factor analysis showed that,under the dangerous loading paths of water pres-sure followed by axial force and water pressure followed by cyclic bending moment,the existence of water pressure will aggravate the growth rate of the ovality of the pipeline section.Therefore,the ovality of the cross-section will increase in the failure moment and the ultimate bearing capacity of the pipe will decrease.

关 键 词：海底管道 压溃压力 模型试验 加载路径 数值模拟 

分 类 号：TE88[石油与天然气工程—油气储运工程]