弯曲及拉伸荷载作用下的钢管抗压溃性能研究

钢管在海洋油气资源开发中应用广泛,一般依据在位应用时的荷载进行设计,设计理论较为成熟。但在某些安装工况中的拉伸和弯曲荷载与在位荷载具有相同的量级,此时钢管的设计需要考虑安装荷载的影响。本文针对钢管在承受拉伸和弯曲荷载下的抗外压压溃性能开展研究。基于商业软件ABAQUS建立有限元模型,开展钢管压溃实验与带有弯曲荷载下的钢管压溃实验验证有限元模型的正确性,进而利用验证后的数值模型讨论拉伸、弯曲荷载和两者联合作用下对管道抗外压压溃性能的影响。结果表明,弯曲荷载是影响抗压溃性能的重要因素,弯曲荷载的增加都会使极限压溃值显著下降。管道所受拉伸荷载对抗压溃性能有一定的影响,但影响很小,在两者共同作用下极限压溃值随弯曲荷载的增加都出现先增大后减小的现象,而且极值的位置与拉伸荷载的大小和弯曲荷载有关。因此,在抗压溃设计中应重点考虑弯曲荷载对压溃的影响,可忽略拉伸荷载的影响。本文可为海洋管道的安装起到指导作用。

Analysis of steel tube collapse under bending or tensile loading

Steel pipes are widely used in offshore oil and gas resources development.They are generally designed according to the load when in service.The design theory is quite mature.However,in some installation conditions,the tensile and bending loads are of the same order of magnitude.In this paper,the anti-collapse performance of a steel pipe under tensile and bending loads is studied.Its finite element model was established based on the commercial software ABAQUS,and the correctness of the finite element model was verified by the steel tube collapse experiment with bending load collapse,and then the influence of tensile and bending loads on the crushing performance of the pipe against external pressure was discussed by using the verified numerical model.The results show that the bending load is an important factor that affects the collapse performance,and the increase of bending load will decrease the ultimate collapse value significantly.The tensile load has a certain effect on the collapse behavior of the pipeline,but the effect is very small under the joint action of both,the ultimate collapse value first increases and then decreases with the increase of bending load,and the position of the extreme value is related to the size of tensile load and bending load.Therefore,the influence of bending load on collapse should be mainly considered in the compressive collapse design,while the influence of tensile load can be ignored.This work can provide guide to the installation of Marine pipeline