海洋柔性管道骨架层径向压缩行为的数值模拟

Numerical simulation of the radial compression of carcass layers of unbonded flexible pipes

为防止铺设或储运过程中出现径向压缩失效,海洋柔性管道内层设计采用互锁型骨架层。基于有限元数值分析方法,建立骨架层三维有限元模型,研究径向压缩载荷作用下骨架层的力学行为。同时将骨架层简化为圆环,推导了圆环对径向压缩刚度的解析公式。搭建了柔性软管径向压缩性能的实验测试装置,通过骨架层试件的径向压缩测试,验证了有限元模型的正确性;发现传统理论模型的误差较大。数值研究还发现,随着钢带厚度与内径比的增加,骨架层径向压缩刚度会显著增大。建立的有限元数值模型及其分析技术为柔性管道受径向压缩分析和设计提供了有效的技术手段。

The interlocked carcass layers of unbonded flexible pipes are designed to resist the radial compression failure due to installation, storage and transportation. A three dimensional finite element model is developed to sim- ulate the radial compression behavior of the carcass under radial forces. At the same time, by simplifying the car- cass into a ring, an analytic formula of the radial compression stiffness of a ring under radial force is deduced for the carcass. A testing rig is also established for the radial compression of the carcass. Through the radial compression test of carcass specimens, the correctness of the finite element model is verified. At the same time, it is found that the traditional theoretical model has a relatively larger error. Numerical study also shows that the carcass radial compression stiffness obviously increases with the increase of the ratio of its thickness over its diameter. The numeri- cal model and analysis technology presented in this paper provide an efficient method for the design and analysis of radial compression property of the unbonded flexible pipe radial compression in industry.