利用有限元法分析单芯光纤复合海缆扭转与光纤应变的关系

Analysis of the relationship between fiber composite submarine cable torsion and optical fiber strain using finite element

利用有限元法建立了海缆扭转模型,对其进行网格划分、施加扭转载荷,模拟海缆不同角速度下的扭转过程,最终提取了铜导体和光单元的应力、应变数据,并对铜导体的径向和轴向应力、应变分布以及扭转速度与铜导体应力、应变的变化关系进行了分析。结果表明,在同一时刻铜导体径向应力、应变由内到外依次增大,轴向应力、应变分布与扭转角度大小有关;海缆以不同角速度扭转时,铜导体的应力、应变的变化与角速度的大小呈现出了一定的规律,整体趋势一致。最后,建立了光纤应变与铜导体应力的关系函数,为利用光纤传感技术监测海缆的扭转状态提供了理论依据。

The finite element analysis method is proposed to establish the finite element torsion model of single-core fiber composite submarine cable,which is meshed and applied torsion load. In the paper,the process of torsion to submarine cable is simulatedand analyzed. Stress and strain data of copper conductorthe light unit is obtained. The distribution of stress and strain in radial and axial of copper conductor is analyzed. The change relationship between the torsional speed and stress and strain of the copper conductor is analyzed. Results indicate that stress and strain of the inner element of the copper conductor are larger than that of the outer layer in the radial,and the distribution of stress and strain is related to the size of torsion angle in the axial. When submarine cable twists in different angular velocities,there presents a certain regularity between the change of stress and strain of copper conductor and speed of torsion. Finally,the torsion damage process can be represented by piecewise function,which provides the theoretical basis to monitor the fiber composite submarine cable torsion.