基于试验模态分析的大型钢结构折形吊桥的等效模型研究

发布时间：2018-03-19 03:26

本文选题：等效模型　切入点：有限元分析　出处：《合肥工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来,由于钢结构加工技术与施工技术以及预应力混凝土施工技术的飞速发展,大跨度钢管混凝土系杆拱桥和钢结构吊桥在国内得到了迅速发展。对于新建的桥梁,需要通过现场桥梁静、动载试验来评定其设计与施工质量,同时可确定工程的可靠度,并检验和完善桥梁设计理论。而桥梁结构自振特性试验是桥梁试验核心内容之一。实验模态分析的目的是对已有的结构系统进行识别与评价,从中找出结构系统的动态特性及所存在的问题,为验证和修改结构动力学的分析模型提供试验依据。因此,对已有结构进行现场动力试验是非常有必要的。由于桥梁属于大型构筑物以及桥面板横截面构造的多样性和复杂性,采用实体单元建模除了难度较大之外,建模工作量和计算工作量都非常大,采用等效模型计算分析对于桥梁特性的快速计算和提高设计效率来说都有着很重要的参考意义。随着桥梁模型及相关分析软件的发展,桥梁板的等效模型分析会和实际情况越来越接近,这样等效模型的分析对桥梁建设的指导意义就会越来越重要。本文以蚌埠市博物馆中庭内部折形钢结构吊桥为研究对象,探讨对桥面板等效模型的分析。采用实体单元建模难度较大,建模工作量和计算工作量都非常大,采用等效模型计算对于桥梁特性的快速计算和提高设计效率来说都有着很重要的参考意义。考虑采用等效原理将桥面板等效为等厚的桥面板,等效桥面板的宽度保持与原结构一致。为了保证理论动力特性的一致,等效桥面板与原结构抗弯刚度、转动惯量、线密度应保持一致,通过理论分析得到等效截面各部分尺寸参数的计算公式。为此,借助大型有限元分析软件ANSYS建立仿真模型,划分单元,对原结构和等效结构进行静力和动力特性分析,通过对计算结果的对比确定等效分析的效果。结果表明：提出的等效模型能够反映原结构的实际状态,得出的各等效参数可反映出原结构的主要动力特性。
[Abstract]:In recent years, due to the rapid development of steel structure processing technology, construction technology and prestressed concrete construction technology, long-span concrete-filled steel tubular tied arch bridge and steel structure suspension bridge have been developed rapidly in China. It is necessary to evaluate the design and construction quality of the bridge by static and dynamic load test, and to determine the reliability of the project. And the theory of bridge design is tested and perfected. The test of natural vibration characteristics of bridge structure is one of the core contents of bridge test. The purpose of experimental modal analysis is to identify and evaluate the existing structural system. The dynamic characteristics and existing problems of the structural system are found out, which provides the experimental basis for verifying and modifying the analysis model of structural dynamics. It is very necessary to carry on the field dynamic test to the existing structure. Because the bridge belongs to the large structure and the cross-section structure of the bridge deck, it is difficult to use the solid element modeling. The workload of modeling and calculation is very large, and the use of equivalent model is very important for the rapid calculation of bridge characteristics and the improvement of design efficiency. With the development of bridge model and related analysis software, The analysis of the equivalent model of the bridge plate will be more and more close to the actual situation, so the analysis of the equivalent model will be more and more important for the guidance of the bridge construction. This paper discusses the analysis of the equivalent model of bridge deck slab. It is difficult to model with solid element, and the workload of modeling and calculation is very large. The use of equivalent model is very important for the fast calculation of bridge characteristics and the improvement of design efficiency. The width of the equivalent deck slab is the same as the original structure. In order to ensure the consistency of the theoretical dynamic characteristics, the bending stiffness, the moment of inertia and the linear density of the equivalent deck slab and the original structure should be consistent. Through theoretical analysis, the calculation formulas of the dimension parameters of each part of the equivalent section are obtained. For this reason, the simulation model is established with the help of the large-scale finite element analysis software ANSYS, and the static and dynamic characteristics of the original structure and the equivalent structure are analyzed by dividing the elements. The results show that the proposed equivalent model can reflect the actual state of the original structure and the equivalent parameters can reflect the main dynamic characteristics of the original structure.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U446

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