【作者】 赵伟；

【导师】 郭海燕；

【作者基本信息】 中国海洋大学 ， 防灾减灾工程及防护工程， 2014， 硕士

【摘要】 海洋管缆系统是海洋油气开发中的重要结构物之一,脐带缆又是海洋管缆系统中最主要的类型,对海洋油气的开发起着巨大的作用,它的力学性能是大家关注的重点。本文对脐带缆局部力学性能进行了详细的理论分析并采用ANSYS通用有限元软件对其进行了数值模拟,以期为实际工程的设计提供理论指导。首先,详细介绍了海洋管缆力学性能中的截面刚度和强度。这为后面ANSYS数值模拟计算提供了清晰的结构概念。讨论了单根螺旋线的拉扭的力学性能,有助于理解运用脐带缆拉扭理论计算模型。由于脐带缆是多层材料复合而成,在力学的数值分析方面接触分析是必不可少的。归纳了ANSYS接触分析的分析步骤和注意事项。通过同一个实例的不同单元对比,确定在接触分析时使用的最优单元。然后,对无铠装钢管脐带缆的轴向拉伸刚度和弯曲刚度进行理论分析和ANSYS数值计算模拟,并进行了结果比较。ANSYS数值模拟中采用点与点接触分析。在轴向拉伸刚度分析中边界条件相同情况下,理论解与数值解的结果在一定的误差范围内吻合较好。增加管缆中螺旋管件的角度会降低管缆的轴向拉伸刚度。增加管件之间的摩擦系数会提高轴向拉伸刚度。通过对边界条件的分析,数值模拟的模型更接近实际工况。对于其弯曲刚度的分析,在螺旋管线之间发生滑移之前,理论分析结果与数值计算结果相比误差较小。当螺旋管线发生滑移时,数值模拟的弯曲刚度迅速降低。最后,对带铠装钢管脐带缆的轴向拉伸、弯曲和扭转进行数值模拟并与理论计算比较。ANSYS数值模拟采用BEAM189自定义梁截面和点与点的接触分析的方法。轴向拉伸刚度的数值计算与理论解误差较小；通过数值模拟得出,在拉伸荷载作用下铠装层是主要受力构件。脐带缆弯曲模拟中刚度的数值计算与理论解在螺旋角度较小时误差较大；随着螺旋角度增大,误差逐渐减小。在弯曲荷载作用时,内部钢管承受的应力要比铠装钢丝的应力大,钢管更容易达到屈服点。对于扭转变形的分析得出,增大管件之间的摩擦系数和螺旋角度,扭转刚度都会增加。更多还原

【Abstract】 Marine pipe line system is one of the important structures in the offshore oil and gas development. Umbilical cable system is the most important type of the marine pipe line system and it plays a huge role for offshore oil and gas development, so its mechanical properties are focused for every researcher. In this paper, the local mechanical properties of the umbilical cable are analyzed theoretical analysis and simulated numerical calculation by ANSYS in detail. The purpose is to provide theoretical guidance for actual engineering design.Firstly, mechanical properties of marine pipe lines in section stiffness and strength is introduced in detail. This provides a clear structure concept for the following ANSYS numerical simulation. The single spiral line mechanical properties of tension-torsion are discussed, which is help for understanding and applying the umbilical cable tension-torsion theoretical model. Due to the umbilical cable composed of multilayer material, contract analysis is indispensable part for mechanical numerical analysis. Those are summarized of analysis steps and cautions about ANSYS contract analysis. The best of elements are selected for contract analysis by an comparison of different elements in the same example.Secondly, the tension stiffness and bending stiffness of unarmored steel umbilical cable are calculated in theoretical analysis and numerical simulation and those results are also compared. Point and point contract analysis is used of numerical simulation of ANSYS. The theoretical and numerical results are in good agreement within a certain error range about axial tension stiffness when those have the same boundary conditions. When the angle of spiral lines becomes larger, the axial tension stiffness of the umbilical cable becomes less and it becomes bigger when the coefficient of friction becomes bigger. The numerical simulation model is closer to actual working conditions by the analysis of the different boundary conditions. For analysis of the bending stiffness, the numerical analysis is little errors compared to theoretical analysis before slippage occurs between the spiral lines. However, when the slippage has occurred, the bending stiffness of numerical analysis deceases rapidly.Finally, the tension stiffness bending stiffness and torsion stiffness of armored steel umbilical cable are researched by numerical analysis and their result is compared to one of theoretical analysis. The method that we own definite beam section in BEAM189element and apply to point and point contract analysis is used for the numerical simulation of ANSYS. The theoretical and numerical results are in good agreement within a certain error range about axial tension stiffness. By the numerical simulation analysis, armored steel wires are the main force components when armored steel umbilical cable is forced tension loads. The bending stiffness of it is larger errors compared to theoretical analysis when the angle of spiral lines is little. But with the angle of it becomes larger, the errors become less. The stress of internal pipes are, larger than one of armored steel wires when armored steel umbilical cable is forced bending loads and internal pipes get yields more easily. When the friction coefficient of pipe lines and the angle of spiral lines become larger, the torsion stiffness becomes larger by the numerical simulation of torsion deformation.更多还原