基于CFD的自由耦合振动法计算桥梁颤振临界风速

发布时间：2018-04-27 11:34

本文选题：CFD数值模拟 + 自由耦合振动法　；参考：《长安大学》2017年硕士论文

【摘要】：借助CFD数值模拟方法来研究大跨桥梁颤振稳定性已然成为一种经济、有效的研究手段。为可以与风洞实验在各个阶段进行直接对比,本课题提出一种基于CFD的自由耦合振动法计算桥梁颤振临界风速的方法。围绕着该种方法,进行了如下工作:首先,简要介绍了目前研究桥梁颤振的三大方法,同时指出本课题的自由振动耦合法提出的必要性;对经典的桥梁颤振理论进行总结并做简要论述,为本课题提供坚实理论基础;简要介绍了CFD的基本理论、网格划分以及参数设定等。然后,为验证并完善本课题的基于CFD的自由耦合振动法,以理想薄平板理论解为对比依据。同时提出三种不同方案来优化UDF文件,确定纽马克方程的?参数使流固耦合效应更加适合本课题需要。对比分析八个颤振导数后,发现自由耦合振动法在主颤振导数和部分副颤振导数的识别上表现良好。最后,结合棋盘洲长江公路大桥的风洞实验结果探讨自由耦合振动法在实际工程中的表现。棋盘洲长江公路大桥的原方案和施加导流板方案的颤振临界风速与使用CFD自由耦合振动法计算出的颤振临界风速误差从1.42%到9.90%不等,说明本课题的方法表现良好。为继续探讨自由耦合振动法的适用性、方便类似工程应用,提出了颤振快速识别方法,同时讨论了千米级大跨悬索桥扭弯频率比对颤振临界风速的影响。
[Abstract]:It has become an economic and effective method to study flutter stability of long span bridges by means of CFD numerical simulation. In order to compare directly with the wind tunnel experiment in each stage, this paper presents a method of calculating the critical flutter velocity of bridge based on the free coupling vibration method based on CFD. The following work has been done around this method: firstly, three methods of bridge flutter research are briefly introduced, and the necessity of the free vibration coupling method is pointed out. The classical bridge flutter theory is summarized and briefly discussed, which provides a solid theoretical basis for this topic, and briefly introduces the basic theory of CFD, mesh generation and parameter setting. Then, in order to verify and perfect the free coupling vibration method based on CFD, the theoretical solution of ideal thin plate is compared. At the same time, three different schemes are proposed to optimize the UDF file and determine the Newmark equation. Parameters make the fluid-solid coupling effect more suitable for this subject. After comparative analysis of eight flutter derivatives, it is found that the free coupling vibration method performs well in the identification of main flutter derivatives and partial secondary flutter derivatives. Finally, combined with the wind tunnel test results of Qipanzhou Yangtze River Highway Bridge, the performance of the free coupling vibration method in practical engineering is discussed. The flutter critical wind speed of Qipan River Highway Bridge and the flutter critical wind speed calculated by CFD free coupling vibration method range from 1.42% to 9.90%, which shows that the method presented in this paper performs well. In order to continue to discuss the applicability of the free-coupling vibration method and to facilitate similar engineering applications, a rapid flutter identification method is proposed, and the influence of torsional and bending frequency ratio on flutter critical wind speed of a long-span suspension bridge with kilometer is also discussed.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441.3

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