曲线梁桥“弯扭耦合”效应影响因素分析研究

发布时间：2018-07-03 17:06

本文选题：曲线梁桥 + 弯扭耦合　；参考：《重庆交通大学》2014年硕士论文

【摘要】：随着我国交通建设事业的迅速发展，曲线梁桥在桥梁建设领域中得到了日益广泛的应用。本文在已有曲线梁桥理论研究的基础上，借助有限元软件midasCivil，通过梁格法建模分析，针对曲线梁桥特有的“弯扭耦合”效应及其影响参数进行研究，主要内容如下： ①在回顾曲线梁桥国内外发展历程的基础上，总结曲线梁桥的各种计算理论及各种理论的相对特点和适用范围；然后从曲线梁桥的受力特性中提出其特有的“弯扭耦合”效应，并简要说明了研究该内容的意义及价值。 ②分析曲线梁桥“弯扭耦合”效应的数学原理及其解析解法，通过微梁段数学模型的平衡方程、几何方程及内力与变形关系的理论推导，得出曲线梁桥“弯扭耦合”效应的主要影响因素，主要包括曲率半径、截面尺寸、横隔板布置、荷载作用位置及支座布置等影响因素。 ③通过曲线梁桥现在比较常用的有限元分析方法的特点及应用对比，说明梁格单元对本文曲线梁桥建模分析的适宜性；接着阐述了梁格单元法建模模拟理论，，并对建模过程中建模要点及计算结果处理分析作了必要的说明。 ④运用有限元计算软件midas Civil梁格法建模分析，通过改变影响参数，取不同的曲率半径、梁体高度、单跨横隔板布置数量、车道荷载作用位置及支座偏心，进行桥梁受力和变形计算对比，分析得出不同参数对曲线梁桥“弯扭耦合”效应的影响。分析结果表明：曲线梁桥随着曲率半径的增加，其受力特性受“弯扭耦合”效应的影响越来越弱，当曲率半径r90m时，“弯扭耦合”对结构受力的影响十分明显，当曲率半径90r190m时，对结构受力的影响变化相对较弱，当曲率半径r190m时，对结构受力的影响变化已经非常微弱，最终趋近于直线梁桥受力特性；曲率半径对“弯扭耦合”效应的影响十分明显，而梁体高度、横隔板设置数量、荷载作用位置、支座的偏移虽然可以对曲线梁桥的“弯扭耦合”效应有所改善，但对其影响相对较小，效果并不明显；但支座的外侧偏移可以有效调整支座反力及截面扭矩的大小。因此，在曲线梁桥设计中，条件允许下应尽量采用大曲率半径；截面尺寸选取时，在截面抗弯刚度满足要求的前提下，应尽量增加抗扭刚度，使弯扭刚度比减小，故曲线梁桥截面设计时优先选取低高度梁和抗扭惯性矩较大的闭口的箱形截面；支座布置时，应考虑抗扭支座的设置及一定的支座偏心。
[Abstract]:With the rapid development of traffic construction in China , the curved beam bridge has been widely used in the field of bridge construction . Based on the research of the existing curve beam bridge theory , this paper studies the characteristic of curved beam bridge with the finite element software , midasCivil , by means of beam grid method modeling and analysis . The main contents are as follows :

On the basis of reviewing the development course of curved beam bridge at home and abroad , the relative characteristics and application range of various calculation theories and various theories of curved beam bridge are summarized .
Then , the special " bending - torsional coupling " effect is proposed from the stress characteristics of the curved beam bridge , and the significance and value of the research are briefly described .

In this paper , the mathematical principle and analytical method of the " bending - torsional coupling " effect of curved beam bridge are analyzed , and the main influencing factors of the " bending - torsional coupling " effect of curved beam bridge are derived by the equilibrium equation , geometric equation and internal force and deformation relation of the mathematical model of the micro - beam section .

( 3 ) By comparing the characteristics of finite element analysis method commonly used in curved beam bridge , this paper illustrates the suitability of beam lattice unit to the modeling analysis of curved beam bridge in this paper .
Then , the modeling simulation theory of beam grid element method is described , and the key points of modeling and the analysis of calculation result are given .

4 . The influence of different parameters on the " bending - torsional coupling " effect of curved beam bridge is analyzed by changing the influence parameters , taking different radius of curvature , height of beam body , arranging quantity of single - span transverse diaphragm , loading action position of the lane and eccentricity of the support , and comparing the stress and deformation of the bridge .

The results show that , with the increase of radius of curvature , the force characteristics of curved beam bridge are more and less affected by the effect of " bending and torsional coupling " . When the radius of curvature is r90m , the effect of " bending and torsional coupling " on the stress of the structure is quite obvious . When the radius of curvature is 90r190m , the influence of the stress on the structure is very weak , and finally approaches the force characteristic of the linear beam bridge .
The influence of radius of curvature on the " bending - torsional coupling " effect is very obvious , while the beam height , the number of the transverse diaphragm and the position of the load action , the deflection of the support can improve the " bending - torsional coupling " effect of the curved beam bridge , but the effect is relatively small and the effect is not obvious ;
but the lateral deviation of the support can effectively adjust the reaction force of the support and the magnitude of the cross - sectional torque .

Therefore , in the design of curved beam bridge , the large radius of curvature should be adopted as far as possible ;
When the cross - sectional dimension is selected , the torsional stiffness should be increased as much as possible under the condition that the flexural rigidity of the cross - section meets the requirements , so that the rigidity ratio of the bending torsion is reduced , so that the cross section of the curved beam bridge preferentially selects a closed box - shaped cross section with a low height beam and a large torsional moment inertia moment ;
The arrangement of the anti - torsion support and the eccentricity of the bearing shall be considered when the support is arranged .
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.21;U441

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