海洋动态缆的截面布局及数值模拟研究

The Sectional Layout and Numerical Simulation Study of Marine Dynamic Cables

脐带缆是海洋动态缆的主要类型,通常由不同功能的单元组装而成,外层一般由铠装钢丝螺旋缠绕和聚合物护套组成。脐带缆在敷设安装和在位运行时,受到拉伸荷载作用,外层铠装钢丝由于其螺旋缠绕特点,会将拉伸荷载转化成径向压力作用到脐带缆内芯上,使脐带缆截面产生应力和变形,所以径向压力是截面布局设计的重要参数。本文推导了脐带缆在轴向拉力作用下对内芯产生的径向压力P,同时基于截面布局多边形的概念,可以绘制多边形图,由图能直观的反映截面的承载能力和各单元受力均匀情况。最后以一个包含不同单元的脐带缆为例,运用ANSYS有限元软件,进行了不同截面布局的建模计算和分析,考虑了单元间的接触和摩擦,给出了数值分析结果,通过对径向荷载作用下截面变形和单元最大受力的比较分析,结合截面布局多边形图,确定了合理布局方案。对脐带缆截面布局设计有重要指导意义。

Umbilical cable, which is consist of different functional units, is the main type of marine dy- namic cables, and the outer layer of the umbilical cable is composed by the spirally wound armoured steel wires and the polymer cover. When is laying, installing and incumbent running, the umbilical cable will be under tensile loads. Because of the spiral wound characteristics of the outer armoured steel wires, the ten- sile load will be transformed into radial pressure which is applied to the inner core of umbilical cable, and it will result in stress and deformation of umbilical cross section. So when it comes to the sectional layout designing, the radial pressure is an important parameter should be considered. This paper deduces the ra- dial pressure P of the inner core under the effect of the axial tension, and at the same time, we can map the polygon on the basis of the concept of polygonal cross-section layout. The bearing capacity of the cross section and the condition of uniform forces of each unite can be reflected intuitively through the polygon. Finally, the paper takes an umbilical cable which includes different unites as an example. Considered the contact and friction between the units, the modeling calculation and analysis are carried out by using the fi- nite element software ANSYS, the results of numerical analysis are given, and the reasonable layout scheme is determined through the comparative analysis between the deformation of cross section and the maximum stress of the unite under the effect of radial loads. The paper has an important significance for the sectional layout design of the umbilical cable.