非黏结柔性管骨架层径向抗压能力计算方法

骨架层作为非黏结柔性管抗径向压力层，其性能决定了柔性管的安装性能和作业深度。但由于骨架层结构复杂，传统方法难以准确计算其抗压性能。通过骨架层截面等效方法，并利用压缩试验、三维及二维有限元方法和理论方法分析了骨架层的压缩性能。计算结果表明：(1)在对径压缩刚度分析中，三维有限元方法与试验结果误差为8.29%,截面等效的理论方法与试验结果误差为1.86%;(2)在均匀压缩临界载荷分析中，使用有限元方法并计入骨架层塑性参数才能获得准确的临界压溃载荷，三维有限元方法及截面等效的二维有限元方法与试验结果的误差分别为1.18%和0.88%。研究结果表明，骨架层压缩模型及骨架层截面等效方法具备实用性，能为骨架层设计及性能评估提供简便、可靠的方法。

Calculation method of radial compression capacity of carcass layer of unbonded flexible pipes

Carcass layer is known as the anti-radial pressure layer of unbonded flexible pipe, whose performance determines the installation performance and operation depth of flexible pipe. However, due to the complex structure of carcass layer, it is difficult to accurately calculate its compressive properties using traditional methods. Therefore, this paper proposes the cross section equivalence method of carcass layer, and the compression performance of carcass layer is analyzed by experimental, three-dimensional and two-dimensional finite element methods, as well as theoretical method. The calculation results show that:(1) in the analysis of radial compression stiffness, the error between the the result from the three-dimensional finite element method and the experimental result is 8.29%, and that between the results from the cross section equivalence method and the experimental result is 1.86%; (2) when analyzing the critical collapse load of uniform compression, it can be only obtained by using the finite element method and taking into account the plasticity parameters of carcass layer, and the error between the results of the three-dimensional finite element method and the two-dimensional finite element method of cross section equivalence and the experimental result is 1.18% and 0.88%, respectively. The results show that the compression model and cross section equivalence method of carcass layer are applicable and can provide simple and reliable methods for the design and performance evaluation of carcass layer.