悬索桥主缆非线性计算分析及影响因素研究

发布时间：2018-04-03 05:04

本文选题：悬索桥　切入点：主缆线形　出处：《重庆交通大学》2015年硕士论文

【摘要】：悬索桥是以主缆为主要承重结构的桥梁,由于悬索桥跨越能力大,造型优美,经济合理,因而是大跨度桥梁的首选桥型。为了对寸滩长江大桥进行准确的施工监控,同时也针对悬索桥主缆具有强烈几何非线性的特点,本文以悬索桥主缆为重点研究对象,并以在建的寸滩长江大桥为工程背景进行了计算分析,探讨了悬索桥主缆的线形计算理论和几何非线性有限元理论,并探索了一些实用的计算分析方法。本文所做的主要工作如下:首先,介绍了悬索桥的传统抛物线理论、近似的分段悬链线(忽略主缆弹性伸长导致的自重集度yq改变)和精确的分段悬链线(考虑主缆弹性伸长导致的自重集度yq改变)。利用MATLAB对这三种理论分别编制了相应的计算程序,并对寸滩长江大桥进行了计算,由此对3种理论的计算结果进行了比较和误差分析。其次,介绍了鞍座位置计算方法,对鞍座位置计算的基本方程式重新进行了严密地数学推导,在采用该基本方程式进行计算时可以将所有已知参数均直接代入正的数值进行求解;运用MATLAB编制了索鞍位置计算模块,分别对寸滩长江大桥南北主索鞍进行了解析计算,并与设计图纸上所给参数进行了对比,结果吻合良好;对两种理论顶点定义下索鞍位置计算的结果也进行了对比分析。再次,介绍了Midas Civil中悬索桥的有限元分析理论以及分析方法,探索了一种在Midas Civil中精确模拟悬索桥的方法,在有限元模型中对主索鞍和散索鞍均进行了模拟,对寸滩长江大桥的成桥状态和空缆状态进行了计算分析,且与设计值进行了对比,计算值与设计值吻合良好;利用有限元模型分析了索鞍对主缆内力与线形的影响;本文也将解析法与有限元方法进行了对比,解析算法和有限元法所得到的结果吻合良好。最后,分析了跨度变化、索长变化和温度变化对空缆线形的影响,并得到了3个适用于寸滩长江大桥空缆状态的线形修正关系式;本文还利用了有限元法来探讨温度对空缆状态下主缆线形的影响,并分别对中跨跨中标高及两主索鞍预偏量随温度改变的变化值进行了二次曲线拟合;主缆跨中标高随着计算温度的升高而降低,而索鞍的预偏量随着计算温度的升高而减小。
[Abstract]:Suspension bridge is a bridge with main cable as its main load-bearing structure. It is the preferred bridge type for long-span bridges because of its large span capacity beautiful shape and reasonable economy.In order to monitor the construction of Putan Yangtze River Bridge accurately, and in view of the strong geometric nonlinearity of the main cable of the suspension bridge, this paper focuses on the main cable of the suspension bridge.The calculation and analysis of the main cable of the suspension bridge based on the construction of the Putan Yangtze River Bridge are carried out, and the calculation theory of the main cable and the geometric nonlinear finite element theory are discussed, and some practical calculation and analysis methods are explored.The main work of this paper is as follows: firstly, the traditional parabola theory of suspension bridge is introduced.The approximate piecewise catenary (neglecting the change of the weight set yq caused by the elastic elongation of the main cable) and the precise piecewise catenary (considering the change of the self-weight yq caused by the elastic elongation of the main cable).The corresponding calculation programs for the three theories are compiled by using MATLAB, and the calculation of the Putan Yangtze River Bridge is carried out. The results of the three theories are compared and the errors are analyzed.Secondly, the calculation method of saddle position is introduced, and the basic equation of saddle position calculation is deduced again.When using this basic equation, all known parameters can be directly replaced in the positive value, and the calculation module of cable saddle position is compiled by MATLAB, and the analytic calculation of the north and south main cable saddles of Putan Yangtze River Bridge is carried out respectively.The results are in good agreement with the parameters given on the design drawings, and the calculation results of the saddle position under the definition of two theoretical vertices are also compared and analyzed.Thirdly, the theory and method of finite element analysis of suspension bridge in Midas Civil are introduced, and a method of simulating suspension bridge in Midas Civil is explored. In the finite element model, the saddle of main cable and the saddle of loose cable are simulated.In this paper, the bridge state and empty cable state of Putan Yangtze River Bridge are calculated and analyzed, and compared with the design value, the calculated value is in good agreement with the design value, and the influence of cable saddle on the internal force and line shape of main cable is analyzed by using finite element model.The analytical method and the finite element method are compared in this paper. The results obtained by the analytical method and the finite element method are in good agreement.Finally, the effects of span change, cable length change and temperature change on the cable shape are analyzed.The finite element method is also used to study the effect of temperature on the shape of the main cable under the condition of aerial cable, and the quadratic curve fitting is carried out for the variation of the mid-span elevation and the pre-deflection of the saddle of the two main cables with the change of temperature.The central elevation of the main cable decreases with the increase of the calculated temperature, while the predeflection of the saddle decreases with the increase of the calculated temperature.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.25

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