内外拱式钢箱系杆拱桥自振特性研究及优化

发布时间：2018-07-11 15:14

本文选题：内外拱 + 自振特性　；参考：《安徽工业大学》2014年硕士论文

【摘要】：内外拱式钢箱系杆提篮拱桥是以每侧内、外双拱代替传统每侧单片拱肋的新桥型，该桥型具有造型美观、结构新颖、施工效率高等优点。本文对内外拱式钢箱系杆提篮拱桥动力特性进行研究，，文章主要内容包括：整理、归纳拱桥结构振动分析的相关理论，阐述自振特性解析法和有限元法的求解思路，为后续分析做好理论储备；运用能量法演引纯拱结构面内基频的近似计算公式，通过MATLAB和ANSYS算例验证近似公式的可靠性，阐明拱结构振动规律。建立阳湖大桥空间有限元模型，对该桥进行有限元模态分析。为准确测定结构动力特性，设计了详尽的模态试验方案，对阳湖大桥开展基于环境激励下的模态试验研究，试验获得模态参数识别需要的振动数据。利用多种时域、频域对模态参数进行识别，获得该桥前6阶固有频率、振型及阻尼比，试验结果与计算结果吻合较好，表明本次试验方法正确，理论计算模型能很好的预测该桥的动力学特性，为阳湖大桥今后各种复杂动力响应分析、长期健康检测和使用状态评估提供可靠的基准模型。在验证计算模型可靠性的前提下，探讨矢跨比、内倾角、风撑布置及拱肋刚度对此类内外拱式拱桥自振特性的影响。分析初步阐明各设计参数对内外拱式拱桥振动特性的敏感性，避免后续优化过程中设计变量选取的盲目性，提高优化效率。利用有限元软件ANSYS编制基于APDL的优化模型，选用零阶优化算法对模型进行动力优化设计，优化结果满足设定的约束条件，优化后的设计参数使内外拱式拱桥面内基频极大化，改善此类拱桥的动力性能。
[Abstract]:The internal and external arch type steel box tie basket arch bridge is a new type of bridge with double arch on each side instead of the traditional single arch rib on each side. The bridge type has the advantages of beautiful shape, novel structure and high construction efficiency. In this paper, the dynamic characteristics of the inner and outer arch steel box tie basket arch bridges are studied. The main contents of this paper are as follows: sorting out, summarizing the relevant theories of the structural vibration analysis of the arch bridges, and expounding the analytical method of the natural vibration characteristics and the solution of the finite element method. In order to make the theoretical reserve for the subsequent analysis, the approximate calculation formula of in-plane fundamental frequency of pure arch structure is derived by energy method. The reliability of the approximate formula is verified by MATLAB and ANSYS examples, and the vibration law of arch structure is clarified. The finite element model of Yanghu Bridge is established, and the finite element modal analysis of the bridge is carried out. In order to accurately measure the dynamic characteristics of the structure, a detailed modal test scheme was designed. The modal test of Yanghu Bridge based on environmental excitation was carried out, and the vibration data needed for modal parameter identification were obtained. The modal parameters are identified in different time and frequency domains, and the first 6 natural frequencies, modes and damping ratios of the bridge are obtained. The experimental results are in good agreement with the calculated results, which shows that the test method is correct. The theoretical calculation model can well predict the dynamic characteristics of the bridge, and provide a reliable benchmark model for the complex dynamic response analysis, long-term health detection and service state evaluation of Yanghu Bridge in the future. On the premise of verifying the reliability of the calculation model, the effects of rise-span ratio, inclination angle, wind brace arrangement and arch rib stiffness on the natural vibration characteristics of this kind of arch bridge are discussed. The sensitivity of the design parameters to the vibration characteristics of the internal and external arch bridges is analyzed. The blindness of the selection of design variables in the subsequent optimization process is avoided and the optimization efficiency is improved. The optimization model based on APDL is compiled by the finite element software ANSYS, and the dynamic optimization design of the model is carried out by using zero order optimization algorithm. The optimization results meet the set constraint conditions, and the optimized design parameters maximize the in-plane fundamental frequency of the internal and external arch bridge. Improve the dynamic performance of such arch bridges.
【学位授予单位】：安徽工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3;U448.225

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