【摘要】 沙丘流动会导致埋地输油管道发生悬空，处于长距离悬空状态下的输油管道会发生断裂、变形等失效形式。为了探究输油管道在不同悬空状态下的力学特性，通过有限元分析软件ANSYS Workbench建立管-沙土有限元模型，在综合考虑沙土物理特性以及管-沙土非线性接触的基础上，基于热-流-固单向耦合方法分析处于不同工况下的悬空输油管道在多载荷作用下的应力变形特性，并对悬空输油管道的极限状态进行安全评估。结果表明：热应力对悬空输油管道力学特性的影响不可忽略；随着悬空长度增加最大Mises等效应力发生的位置由悬空中心处变为悬空段与埋地段的分界处；在考虑热应力的基础上，最大Mises等效应力随悬空长度增加呈现先增大后减小再增大的趋势；在综合影响下，算例中的悬空输油管道极限长度为77.41 m。更多还原

【Abstract】 Sand dune flow can cause buried oil pipelines to become suspended, and oil pipelines in a long distance suspended state may experience failure forms such as fracture and deformation. In order to explore the mechanical characteristics of oil pipelines under different suspended states, a finite element model of pipeline sand soil using the software ANSYS Workbench was established. Based on the comprehensive consideration of the physical characteristics of sand and the nonlinear contact between the pipeline and the sand, the stress and deformation characteristics of suspended oil pipelines under multiple loads under different working conditions were analyzed using the method of thermal-fluid-solid unidirectional coupling. Based on the above results, the safety assessment of the limit state of suspended oil pipelines was conducted. The results indicate that the influence of thermal stress on the mechanical properties of suspended oil pipelines cannot be ignored. As the length of the suspension increases, the location where the maximum Mises equivalent stress occurs changes from the center of the suspension to the boundary between the suspended section and the buried section. On the basis of considering thermal stress, the maximum Mises equivalent stress shows a trend of firstly increasing, then decreasing, and then increasing with the increase of the suspension length. Under the comprehensive influence, the ultimate length of the suspended oil pipeline in the calculation example is 77.41 m.更多还原