深海柔性立管弯曲加强器力学建模及参数敏感性分析

柔性立管系统在深海资源开发中使用越来越广泛。弯曲加强器作为立管系统的重要构件,其设计和研究对立管系统在复杂工况下的正常作业有着十分重要的意义。同时考虑材料的非线性力学行为、几何大变形,以及弯曲加强器与立管之间的接触摩擦,建立典型三段式弯曲加强器-立管系统的三维非线性力学模型,并与工程常用线性简化模型结果进行对比,说明非线性力学建模的必要性。在此基础上,通过非线性计算对典型三段式弯曲加强器的关键结构设计参数进行敏感性分析。结果表明,弯曲加强器的各段长度比例、厚度等结构参数对系统工作性能都有一定影响,在弯曲加强器设计时应给予充分考虑。

Mechanical Modelling and Sensitivity Analysis of Bending Stiffeners of Deep-sea Flexible riser

Flexible riser system has been more and more widely used in deep-sea resource exploitation. As an important component of riser system, the design and research of bending stiffener are of great significance to guarantee the capability of the riser system under complex working conditions. A three-dimensional non-linear model for the typical three-segment-typed bending stiffener and riser system was established, considering the nonlinear constitutive law, the large deformation, as well as the contact, friction and clearance between the bending stiffener and riser. The necessity of the nonlinear model was verified through comparing the nonlinear results with the results by using simplified linear model. Based on the proposed nonlinear approach, the sensitivity of the key structural parameters of typical three-segment-typed bending stiffener was analyzed further. The results show that the structural geometric parameters including the length ratio and thickness of each section of the bending stiffener take influence on the work capacity of the riser system, and more consideration should be given in design of the bending stiffener.