【摘要】：柔性管、臍帶纜等海洋柔性管線結(jié)構(gòu)的截面等效拉伸模量和等效彎曲模量不僅具有嚴(yán)重的差異性，而且具有強(qiáng)烈的非線性，因此將這種現(xiàn)象稱之為特殊材料非線性。本文主要研究特殊材料非線性特性對(duì)海洋柔性管線的靜力在位形態(tài)的影響。 本文將海洋柔性管線的軸向不易延伸特性作為拉格朗日條件引入位能泛函，構(gòu)造二節(jié)點(diǎn)三維空間梁?jiǎn)卧?4自由度的混合元，選取合適的廣義位移自由度插值函數(shù)，構(gòu)造廣義單元應(yīng)變和廣義單元應(yīng)力，確定幾何關(guān)系矩陣和本構(gòu)關(guān)系矩陣。推導(dǎo)出單元增量平衡方程，獲得單元切線剛度矩陣，建立靜態(tài)有限元模型。為了精確扣除單元?jiǎng)傮w位移，推導(dǎo)出從單元隨轉(zhuǎn)坐標(biāo)系到總體坐標(biāo)系的單元節(jié)點(diǎn)位移轉(zhuǎn)換矩陣，并給出隨轉(zhuǎn)載荷、非隨轉(zhuǎn)載荷和單元節(jié)點(diǎn)內(nèi)力的計(jì)算方法。依據(jù)上述理論編制Matlab有限元程序，并對(duì)連接水面船舶和水下轉(zhuǎn)塔的柔性立管、受到海流作用的垂直立管兩個(gè)算例進(jìn)行驗(yàn)證，計(jì)算結(jié)果表明所編程序在計(jì)算結(jié)構(gòu)的靜力構(gòu)型方面是可靠的。最后深入研究了等效拉伸模量非線性變化、等效彎曲模量非線性變化以及等效拉伸模量和等效彎曲模量比例關(guān)系對(duì)柔性管線這類結(jié)構(gòu)靜力在位形態(tài)的影響，，并得出相關(guān)結(jié)論： （1）非線性等效拉伸模量對(duì)結(jié)構(gòu)的靜力在位整體形態(tài)影響不顯著，但是對(duì)結(jié)構(gòu)的局部形態(tài)有較大的影響；隨著海流流速的增大，其對(duì)結(jié)構(gòu)構(gòu)型的影響越來(lái)越弱； （2）非線性等效彎曲模量比前者更能影響結(jié)構(gòu)的靜力在位形態(tài)，尤其是針對(duì)結(jié)構(gòu)局部形態(tài)的影響；隨著海流流速增大，其對(duì)結(jié)構(gòu)的靜力在位整體形態(tài)和局部形態(tài)的影響效應(yīng)會(huì)擴(kuò)大； （3）隨著等效拉伸模量和等效彎曲模量比例關(guān)系的變化，柔性立管的靜力整體在位形態(tài)和局部形態(tài)有著顯著的變化。
[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.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：P756.2

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相關(guān)期刊論文 前2條

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本文編號(hào)：2354825