非线性复合管线的静态在位数值分析研究
发布时间：2018-11-24 19:49
【摘要】：柔性管、脐带缆等海洋柔性管线结构的截面等效拉伸模量和等效弯曲模量不仅具有严重的差异性，而且具有强烈的非线性，因此将这种现象称之为特殊材料非线性。本文主要研究特殊材料非线性特性对海洋柔性管线的静力在位形态的影响。 本文将海洋柔性管线的轴向不易延伸特性作为拉格朗日条件引入位能泛函，构造二节点三维空间梁单元14自由度的混合元，选取合适的广义位移自由度插值函数，构造广义单元应变和广义单元应力，确定几何关系矩阵和本构关系矩阵。推导出单元增量平衡方程，获得单元切线刚度矩阵，建立静态有限元模型。为了精确扣除单元刚体位移，推导出从单元随转坐标系到总体坐标系的单元节点位移转换矩阵，并给出随转载荷、非随转载荷和单元节点内力的计算方法。依据上述理论编制Matlab有限元程序，并对连接水面船舶和水下转塔的柔性立管、受到海流作用的垂直立管两个算例进行验证，计算结果表明所编程序在计算结构的静力构型方面是可靠的。最后深入研究了等效拉伸模量非线性变化、等效弯曲模量非线性变化以及等效拉伸模量和等效弯曲模量比例关系对柔性管线这类结构静力在位形态的影响，，并得出相关结论： （1）非线性等效拉伸模量对结构的静力在位整体形态影响不显著，但是对结构的局部形态有较大的影响；随着海流流速的增大，其对结构构型的影响越来越弱； （2）非线性等效弯曲模量比前者更能影响结构的静力在位形态，尤其是针对结构局部形态的影响；随着海流流速增大，其对结构的静力在位整体形态和局部形态的影响效应会扩大； （3）随着等效拉伸模量和等效弯曲模量比例关系的变化，柔性立管的静力整体在位形态和局部形态有着显著的变化。
[Abstract]:The cross-section equivalent tensile modulus and equivalent flexural modulus of flexible pipeline structures such as flexible tubes and cord cables not only have serious differences but also have strong nonlinearity so this phenomenon is called special material nonlinearity. In this paper, the influence of nonlinear characteristics of special materials on the static in-situ morphology of marine flexible pipelines is studied. In this paper, the axially unextensible characteristic of marine flexible pipeline is introduced into the potential energy functional as Lagrangian condition, and the mixed element with 14 degrees of freedom of two-node three-dimensional space beam element is constructed, and the appropriate interpolation function of generalized displacement degree of freedom is selected. The generalized element strain and generalized element stress are constructed and the geometric relation matrix and constitutive relation matrix are determined. The element increment equilibrium equation is derived, the tangent stiffness matrix is obtained, and the static finite element model is established. In order to deduct the rigid body displacement accurately, the element node displacement transformation matrix from the element coordinate system to the total coordinate system is derived, and the calculation methods of the internal forces of the unit node are given, including the reprint load, the non-reprint load and the internal force of the element node. According to the above theory, the Matlab finite element program is compiled, and two examples of the vertical riser connected with the surface ship and the underwater turret are verified. The results show that the program is reliable in calculating the static configuration of the structure. Finally, the effects of nonlinear variation of equivalent tensile modulus, nonlinear variation of equivalent flexural modulus and proportional relationship between equivalent tensile modulus and equivalent flexural modulus on static in-situ configuration of flexible pipeline are studied. The conclusions are as follows: (1) the nonlinear equivalent tensile modulus has no significant effect on the static in situ shape of the structure, but has a great effect on the local shape of the structure; With the increase of current velocity, the influence on the configuration of the structure becomes weaker and weaker. (2) the nonlinear equivalent modulus of bending can affect the static in-situ shape of the structure more than the former, especially the influence of the local shape of the structure. With the increase of the current velocity, the influence of the current on the whole and the local shape of the structure will be enlarged. (3) with the change of the ratio of equivalent tensile modulus and equivalent flexural modulus, the in situ and local morphology of the flexible riser have significant changes.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P756.2
本文编号：2354825
[Abstract]:The cross-section equivalent tensile modulus and equivalent flexural modulus of flexible pipeline structures such as flexible tubes and cord cables not only have serious differences but also have strong nonlinearity so this phenomenon is called special material nonlinearity. In this paper, the influence of nonlinear characteristics of special materials on the static in-situ morphology of marine flexible pipelines is studied. In this paper, the axially unextensible characteristic of marine flexible pipeline is introduced into the potential energy functional as Lagrangian condition, and the mixed element with 14 degrees of freedom of two-node three-dimensional space beam element is constructed, and the appropriate interpolation function of generalized displacement degree of freedom is selected. The generalized element strain and generalized element stress are constructed and the geometric relation matrix and constitutive relation matrix are determined. The element increment equilibrium equation is derived, the tangent stiffness matrix is obtained, and the static finite element model is established. In order to deduct the rigid body displacement accurately, the element node displacement transformation matrix from the element coordinate system to the total coordinate system is derived, and the calculation methods of the internal forces of the unit node are given, including the reprint load, the non-reprint load and the internal force of the element node. According to the above theory, the Matlab finite element program is compiled, and two examples of the vertical riser connected with the surface ship and the underwater turret are verified. The results show that the program is reliable in calculating the static configuration of the structure. Finally, the effects of nonlinear variation of equivalent tensile modulus, nonlinear variation of equivalent flexural modulus and proportional relationship between equivalent tensile modulus and equivalent flexural modulus on static in-situ configuration of flexible pipeline are studied. The conclusions are as follows: (1) the nonlinear equivalent tensile modulus has no significant effect on the static in situ shape of the structure, but has a great effect on the local shape of the structure; With the increase of current velocity, the influence on the configuration of the structure becomes weaker and weaker. (2) the nonlinear equivalent modulus of bending can affect the static in-situ shape of the structure more than the former, especially the influence of the local shape of the structure. With the increase of the current velocity, the influence of the current on the whole and the local shape of the structure will be enlarged. (3) with the change of the ratio of equivalent tensile modulus and equivalent flexural modulus, the in situ and local morphology of the flexible riser have significant changes.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P756.2
【参考文献】
相关期刊论文 前2条
1 马玉全;;改进CR列式法及在几何非线性分析中的应用[J];科学技术与工程;2010年30期
2 周凌远;李乔;;基于UL法的CR列式三维梁单元计算方法[J];西南交通大学学报;2006年06期
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