壁厚所致几何不连续性对卷管法安装管道的影响

对于深水管道，止屈器起到了很好的防止屈曲传播的作用，但是在卷管法安装中，管道在上卷和退卷的过程中将产生塑性变形，而由于止屈器导致的管道壁厚几何不连续性将使局部管段的变形增大，可能加剧塑性变形的影响。针对这个问题，建立ABAQUS非线性有限元模型模拟管道安装过程，研究上述问题对卷管铺管中管道性能的影响并作参数敏感性分析。结果表明，壁厚所致几何不连续性的存在导致卷管安装时管道局部曲率及应变明显增大；回拉力、管径与卷筒直径之比及管道壁厚等参数也将产生影响。另外，增加回拉力可降低上述不连续性的影响，但管道残余椭圆度也将增加；增大卷筒半径（或减小管道直径）将使不连续性的影响降低；增大管道壁厚可降低不连续性影响，但随之建造成本也将增加。本文研究结论可为卷管法安装中管道设计提供理论指导。

Study of the Effect of Pipe Geometric Discontinuities on Pipe Wall Thickness during Reel-Lay

For deep-water pipeline, buckling arrestor is used to prevent bucking propagation. However, during Reel-lay installation, the pipeline is subject to plastic deform because the pipeline undergoes winding and unwinding.The pipe geometric discontinuities on pipe wall thickness due to buckling arrestor increase the pressure on the pipeline and local deformation, which causes the impact of plastic bending increase. Therefore, non-linear finite element models were built with Abaqus to simulate the process of pipeline installation to study the influence of the above discontinuities and parametric studies were carried out. The results show that the geometric discontinuities lead to obvious increase of the local curvature and the strain of pipeline. The influence of the initial defect is affected by parameters such as back force, the ratio of pipe diameter to drum diameter and pipe wall thickness. Increasing the back tension can reduce the effect of defects, but the residual ovalization is also increased, and increasing the drum radius (or reducing the diameter of the pipe) reduces the effect of defects. Moreover, increasing the pipe wall thickness can reduce the effect of initial defects, but the construction cost also increases. The conclusions of this paper can provide reference for pipelines design of reel-lay installation theoretically.