1摘 要桥梁在一个国家的交通运输和经济发展中占有十分重要的位置，而桥梁的检测则是保证桥梁安全运营的重要手段。随着技术的发展，桥梁检测车已经发展成为专业桥梁检测领域中必不可少的专用设备，桁架式桥梁检测车更是代表了桥梁检测车的主流发展方向，具有广阔的市场前景。本文的研究对象为QJS18C 桁架式桥梁检测车，采用有限元法对该车结构进行了有限元分析和优化。本文认真研究了桥梁检测车的结构组成和工作原理，对桥检车各组成部件进行了合理的模型处理和简化，利用有限元分析软件 ANSYS 的 APDL 语言，采用自底向上的建模方式，建立了各部件的有限元参数化模型。按照真实情况采用合理的方式模拟各部件间的连接关系，将各部件组成一个整体。通过以上工作建立了桁架式桥梁检测车整车的有限元分析模型。本文首先对桥梁检测车整车结构进行了静力分析，选取了桥检车工作过程中常用的 10 种工况，按实际情况施加约束和载荷，获得了不同工况下各部件的应力分布和变形等详细力学性能；针对该 10 种工况，对上车工作装置进行了模态分析，确定了结构的固有频率和模态振型等信息，可避免结构在工作过程中发生共振现象。然后取垂直臂为主要研究对象，采用接触单元来模拟垂直臂与滑块之间的滑动连接，得到了更为精细准确的结果，通过改变垂直臂的结构参数进行分析比较，可以看到不同参数变化对垂直臂性能的影响；取工作平台为主要研究对象，分析了伸缩臂的受力特点，按实际情况进行加载对危险工况下的滚轮和伸缩臂进行了接触分析，获得了接触区域的应力、应变分布，并比较了不同的滚轮材料对接触行为的影响，为设计过程中零部件的选型提供了理论依据。最后为实现整车轻量化和提高整车的性能和稳定性，对关键部件进行了优化和改进，包括对支腿的板厚进行优化减重，对车架平台和一回转设计不合理的地方进行改进等。改进的结果不仅减少了整车重量，而且提高了整车性能。论文中提出的一些方法可用于同类型的桥检车的分析中，论文的分析成果为设计人员对结构的改进和优化提供了理论依据。2关键词关键词：桥梁检测车；有限元分析；模态分析；接触分析3AbstractThe bridge occupies a very important position in a countrys transportation and economic development, and bridge detection is an important means to ensure the safe operation of the bridge. With the development of technology, the bridge inspection vehicle has become an indispensable special equipment in the professional bridge test field, and the truss type bridge inspection vehicle is more representative of the mainstream developing direction of bridge inspection vehicle, which has a broad market prospect. The study object of this paper is a truss type bridge inspection vehicle named QJS18C, the finite element method was used for analysis and optimization of its structure.In this paper we carefully studied the structure and working principle of bridge inspection vehicle, made a reasonable model process and simplification of the components of the vehicle, and established parametric finite element model of its components by using ANSYS Parameter Design Language(APDL), with the from-bottom-to-up modeling strategy. Accroding to the real situation to simulate the connection between the components, the various parts make up a whole. Through the above work, we established the finite element analysis model of the truss type bridge inspection vehicle finally.Firstly, in this paper we conducted the static analysis about the whole bridge inspection vehicle structure. This structure was applied constraints and loads according to the actual situation, selecting the 10 conditions during the working process of bridge inspection vehicle, And then, we can obtained the stress distribution, deformation and other detailed mechanical properties under different working conditions. For these 10 kinds of working conditions, we finished the modal analysis about the above vehicle device on the car and determined the structural natural frequencies, mode shapes, and other informations. It can avoid the resonance phenomenon of the structure in the working process. Then we take the vertical arm as the main area of study, use the contact elements to simulate the sliding connection between the vertical arm and the slider and eventually got preciser and more accurate 4results. By changing the structural parameters referring to the vertical arm to analyze and compare, you can see the effect of different parameters on the performance of the vertical arm. Taking the work platform as the main object of study, this paper analyzed the mechanical characteristics of the arm, developped contact analysis with the rollers and the arm on the dangerous conditions according to the actual situation, getted the stress and strain distribution in the contact area. Meanwhile, this paper compared the different effect of the contact behavior from different rollers materials to provide a theoretical foundation for the choice of components in the process of the design. Finally, to achieve lighter vehicle and to improve its performance and stability, this paper have optimized and improved key components, which include optimizing the thickness of the leg, improving unreasonable locations about the frame and a rotating platform and so on. The results not only reduces the vehicle weight, but also improves vehicle performance.Some methods proposed in the paper can be used for the same type of bridge inspection car.The results of the paper is designed to improve and optimize the structure for personnel to provide a theoretical basis.5目 录 摘 要.1目 录.2第 1 章 绪 论.51.1 课题研究意义.51.2 桥梁检测车概述.71.3 国内外桥梁检测车发展现状及发展趋势9.81.3.1 国外研究现状.