双层海底管道隆起屈曲参数分析

Parametric Analysis of Upheaval Buckling of Submarine Pipe-in-pipe Systems

海底管道在铺设安装过程中可能因为操作不当,使得管道在海底时存在局部的初始隆起.管道初始局部缺陷是诱发海底管道产生屈曲的潜在因素.管道轴向压力是导致海底管道发生屈曲的主要原因.当海底管道在高温载荷下工作时,管道将会由于温度变化引起轴向力的增大而发生隆起屈曲.对于双层管道来说,内管与外管之间的相互作用是非常复杂的,双层管的复杂结构导致其整体屈曲理论分析十分困难,因此提出了一种有限元模型,该模型利用管中管技术分析具有初始缺陷管道的隆起屈曲问题.基于该模型开展了参数分析,得到了管道初始不直度和环隙对海底高温管道发生隆起屈曲的影响趋势.同时这些计算结果对我国实际工程项目中的双层管隆起屈曲分析具有一定的参考价值.

Improper operation in the installation process will make the pipeline an initial local upheaval. The initial local imperfection is the potential factor to induce the upheaval buckling. The axial compressive force is the primary cause of pipeline buckling. The submarine pipeline may be liable to upheaval buckling caused by rise in axial force due to temperature changes. The interaction between the inner pipe and the outer pipe is complicated and the complex structure of PIP system makes the global buckling difficult to tackle in theory analysis. A finite element model is presented to analyze the upheaval buckling of PIP systems with initial local imperfections. The impacting trend of key parameters such as the initial out-of-straightness and annulus is obtained. Furthermore, these calculation results provide the actual projects in china a reference value for the upheaval buckling analysis on subsea PIP system.