Simplified models of multilayered unbonded flexible pipes for offshore applications were manufactured and put to a series of bending tests where biaxial bending strains of tensile armor wires were directly measured. Focusing on the effects of constraint on the tensile armor wires by outer layers on the bending stiffness of the pipe and the bending stresses of tensile armor wires, four types of pipe models with different specifications of holding bandages, which hold the tensile armor layers from the outside, were prepared. Cross-sectional analyses based on four kinds of methods were also carried out and comparatively examined with the above bending test results, and the applicability of each method was evaluated. As a result, it was found that the normal and binormal bending stresses of the tensile armor wires in the slip region remarkably change depending on the specification of the holding bandages, suggesting that the degree of constraint on the tensile armor wires by the outer layers should be taken into consideration in the cross-sectional analyses.

中文翻译：

---

多层柔性管模型的弯曲试验和横截面分析

制造了用于海上应用的多层非粘合柔性管的简化模型，并进行了一系列弯曲试验，其中直接测量了拉伸铠装线的双轴弯曲应变。针对外层对拉伸铠装线的约束对管道弯曲刚度和拉伸铠装线弯曲应力的影响，四种不同规格的固定绷带的管道模型，将拉伸铠装层从外面，准备好了。还进行了基于四种方法的横截面分析，并与上述弯曲试验结果进行了比较，并评估了每种方法的适用性。因此，