柔性管道抗径向挤压能力数值模拟

柔性管道在安装过程中会受到张紧器等安装设备的夹持作用,夹持力过小会引起管道外护套层滑脱,夹持力过大则会导致管道的径向挤压破坏。为预测柔性管道抗径向挤压能力,建立了柔性管道完整截面的三维有限元模型。对管道承受外压的骨架层结构进行径向挤压模拟,发现骨架层结构在加载过程中逐渐演变为含有4个塑性铰的活动机构,且在垂直于挤压方向的结构区域发生屈服时,结构的抗压刚度瞬间下降。对柔性管道不同结构层结构的抗压能力进一步分析,发现骨架层承压占比仅为整个结构的39.01%,安装过程中的抗挤压能力分析若仅考虑骨架层则过于保守。研究成果可为柔性管道抗压能力的预测提供参考。

Numerical simulation on resistance of flexible pipe to radial compression

Flexible pipes are usually clamped by tensioners and other installation tools during installation.Too small clamping force may lead to the peeling of the oversheath of the pipe,while too large clamping force will lead to radial compression damage of the pipe.The three-dimensional finite element model of the complete section of the flexible pipe was established to predict the radial compression resistance of the flexible pipe.Through the radial compression simulation on the carcass structure of the pipe that was subjected to external compression,it was found that the carcass structure gradually evolved into a movable mechanism with four plastic hinges during loading.The compression resistance of the structure dropped instantly when yielding occurred in the structural area perpendicular to the compression direction.Further analysis of the compressive capacity of different structural layers of flexible pipes shows that the contribution rate of the carcass subjected to is only 39.01%of the whole structure,indicating an excessively conservative analysis on the compression resistance if only carcass is considered in the installation process.The research results can provide reference for the prediction of the compression resistance capacity of flexible pipes.