中文摘要：

建立深海非粘结柔性管新型力学数值分析模型,分析其在复合载荷工况下的力学性能。深海非粘结柔性立管是深水资源开发的关键设备,安装成本低,适用于恶劣深海环境。然而,由于非粘结柔性管本身的结构型式复杂以及层与层之间的摩擦、接触等诸多强非线性特性,使其局部力学性能分析面临众多挑战。研究针对非粘结柔性立管特殊的结构型式,建立一个高效的数值分析模型,对其刚度进行数值求解并与实验结果进行对比,探讨了内压和拉伸、扭转、弯曲的组合载荷工况和拉扭组合载荷工况对非粘结柔性立管刚度的影响。研究表明,本文所建立的简化模型计算结果与实验结果吻合较好。此外,柔性立管所受到的内压可以在一定程度上增加非粘结柔性立管的刚度;拉扭组合载荷工况使非粘结柔性立管的拉伸刚度降低明显,而使其扭转刚度少量增加,总体上较单一载荷工况更加危险。

英文摘要：

A new numerical analytical model is established to analyze the mechanical property of the unbonded flexible risers under combined loads. Because of their low installation costs and suitability in the adverse sea conditions, the unbonded flexible risers are the critical equipment for deep water development. However, the local mechanical property of the unbonded flexible riser is hard to analyze due to the complicated structures and the strong nonlinear property of the unbonded flexible risers. Aiming at this problem, a new efficient numerical analytical model is established to solve the stiffness of the riser, and its results are compared with the experimental results. After validating the numerical model, the effects of the combined loads on the stiffness of the unbonded flexible risers are also studied. The results show that the analytical results of the simplified numerical model agree with the experimental results. In addition, the inner pressure could increase the stiffness of the unbonded flexible risers in some degree. The tension-torsion loading case could lead to a distinguished decrease of tension stiffness, but with a little increase of torsion stiffness.