层间摩擦系数对非黏结柔性管抗拉铠装层轴压屈曲失效模式的影响研究

在柔性管运输、铺设安装和服役过程中,由于其抗拉铠装层钢带为柔性细长螺旋结构,当外部载荷超过临界值时,抗拉铠装层钢带容易发生屈曲失效。考虑非线性材料、几何大变形、层间接触和摩擦等非线性效应的影响,运用ABAQUS有限元软件建立了63.5 mm典型非黏结柔性管8层完整结构模型,研究了在抗拉铠装层不同层间摩擦系数的情况下,非黏结柔性管在轴向压缩载荷作用下的力学性能和屈曲失效模式。研究结果表明,层间摩擦系数对非黏结柔性管的抗压刚度和抗拉铠装层屈曲失效模式有较大影响,层间摩擦系数以0.1和0.2为分界点,抗压刚度和屈曲失效模式均呈现出“三段式”变化规律。研究成果可为海洋非黏结柔性管的结构设计和屈曲失效评估提供技术参考。

Research on the influence of interlayer friction coefficient on the axial compression buckling failure mode of unbonded flexible pipe with tensile armor layer

During the transportation, installation, and service of flexible pipes, the tensile armor layer made of flexible and slender spiral steel strips is prone to buckling failure when external loads exceed critical values. Taking into account the nonlinear effects of nonlinear materials, geometric deformation, interlayer contact, and friction, a 63. 5 mm typical unbonded flexible pipe with 8 layers was modeled using ABAQUS finite element software. The mechanical properties and buckling failure modes of the unbonded flexible pipe under axial compression loads were studied under different interlayer friction coefficients of the tensile armor layer. The results show that the interlayer friction coefficient has a significant influence on the compressive stiffness and buckling failure mode of the unbonded flexible pipe. With interlayer friction coefficients of 0. 1 and 0. 2 as the dividing points, both compressive stiffness and buckling failure modes exhibit a "three-stage" variation pattern. The research findings can provide technical references for the structural design and buckling failure assessment of marine unbonded flexible pipes.