ABSTRACT

In an underwater compressed air energy storage system, fracture of the flexible riser often occurs. To solve this problem, we proposed a static analysis method for a flexible riser based on Cosserat theory. Bending and torsion deformation of a flexible riser were described. Using Euler parameters, static equilibrium differential equations were established. Finite element discretization, finite difference, and an improved Levenberg–Marquardt algorithm were used to perform the numerical calculations. Based on the similarity principle, experiments with three different boundary conditions were performed. Our static model and the OrcaFlex simulations were compared with experiments, and the average error of our static model was 2.9% smaller than that of the simulation. The results showed that the static model presented in this paper was more accurate than the OrcaFlex simulation calculation. This model is useful for estimating the mechanical characteristics and determining the strengths of flexible risers.

摘要

在水下压缩空气储能系统中，柔性立管经常发生断裂。针对这一问题，我们提出了一种基于Cosserat理论的柔性立管静力分析方法。描述了柔性立管的弯曲和扭转变形。利用欧拉参数，建立了静态平衡微分方程。有限元离散化、有限差分和改进的 Levenberg-Marquardt 算法用于执行数值计算。基于相似性原理，进行了三种不同边界条件的实验。我们的静态模型和 OrcaFlex 仿真与实验进行了比较，我们静态模型的平均误差比仿真小 2.9%。结果表明，本文提出的静态模型比 OrcaFlex 仿真计算更准确。该模型可用于估计机械特性和确定柔性立管的强度。