摘 要

本设计为滚装码头45米钢引桥的结构设计与优化。钢引桥由于其远岸端能够随水位变化而调整高度，在滚装码头中使用广泛。设计中首先查阅书籍资料和相关规范，了解钢引桥的现状、发展趋势、常用结构形式和设计方法，然后通过比较和计算选择合理的结构形式，确定本设计的整体布置思路，进而根据荷载情况计算各杆件的受力情况从而初步确定各杆件截面形式及尺寸，然后根据结构的强调、刚度、稳定性等要求进行校核，修改危险杆件的截面。最后利用有限元软件ANSYS建模进行优化设计，得到更为合理的最终结构设计。

通过优化设计，根据背景资料和参照的国家规范，本文最终选择的桥梁形式采用桁架式，桥梁跨度45米，桥宽设计为7.5米，主桁高4米，采用平型桁架式，设置上下平纵联。整座桥梁由钢材构成，选用的钢材为Q235钢。设计荷载主要包括桥梁自重、汽车荷载和风力荷载。主桁和横纵梁杆件选用H型钢，平纵联选用T型钢。设计过程中，首先计算设计荷载产生的杆件内力，根据强度条件初步拟定杆件的截面尺寸，然后进行刚度和稳定性的校核，修改不合理的危险杆件的截面尺寸直到满足校核条件。杆件的连接采用高强螺栓连接，设计节点板并同样进行了校核。初步设计之后，利用ANSYS软件创建结构模型并进行校核优化，确定最终桥梁各杆件的截面形式及尺寸。最后利用AUTOCAD软件进行图纸的绘制，主要包括总体布置图、各杆件尺寸图和节点连接图。

本设计对公路钢引桥进行了比较全面的设计，计算过程比较详尽，设计参考了施工实际，相信本文对公路钢引桥的设计和施工能够具有一定的参考价值。

关键词：钢引桥，平行桁架，杆件设计，有限元分析

Abstract

This paper is designed and optimized for the construction of 45 meters steel bridge. Steel bridge because of its far shore can be changed with the water level to adjust the height, widely used in the ro-ro terminal. The design of the first reference to the books and related specifications, to understand the status of steel bridge approach, development trends, commonly used structural forms and design methods, and then through comparison and calculation to choose a reasonable structure to determine the overall layout of the design ideas, and then calculated according to load The stress situation of each bar to determine the initial cross-section of the form and size, and then according to the structure of the emphasis, stiffness, stability and other requirements to check, modify the cross-section of dangerous rods. Finally, the finite element software ANSYS is used to optimize the design, and the more reasonable final structural design is obtained.

By optimizing the design, according to the background data and reference to the national norms, the final selection of the bridge in the form of truss, the bridge span of 45 meters, the bridge design is 7.5 meters, the main trunk height of 4 meters, the use of flat truss, Pilotage. The entire bridge consists of steel, the choice of steel for the Q235 steel. The design load includes bridge weight, car load and wind load. The main truss and the cross-beam members are selected for H-beam, and the T-beam is selected for the vertical connection. In the design process, the internal force of the bar produced by the design load is calculated, and the cross-sectional dimension of the rod is preliminarily prepared according to the strength condition. Then, the stiffness and stability of the rod are checked, and the cross-sectional dimension of the unreasonable dangerous bar is adjusted until the check condition is satisfied The The connection of the rods is made of high strength bolts, and the gussets are designed and checked. After the preliminary design, the ANSYS software was used to create the structural model and the calibration was optimized to determine the cross-sectional form and size of the final bridge. Finally, the use of AUTOCAD software for drawing, including the overall layout, the bar size map and node connection diagram.

The design of the road steel bridge for a more comprehensive design, the calculation process is more detailed, the design reference to the actual construction, I believe this article on the highway steel bridge design and construction can have a certain reference value.

Key words: Steel bridge；parallel truss； bar design； finite element analysis

目录

第一章：绪论.................................................................................................................8

1.1钢引桥概述...........................................................................................................8

1.2设计内容概述.......................................................................................................9

第二章：钢引桥总体布置方案...................................................................................10

2.1桁架基本结构及总体布置..................................................................................10

2.2桥面系基本结构及总体布置..............................................................................10

第三章：主桁结构内力计算与截面选择...................................................................11

3.1主桁杆件内力计算.............................................................................................11

3.2主桁杆件截面选择与校核..................,..............................................................16

第四章：杆件连接设计...............................................................................................21

4.1腹杆杆端连接螺栓数计算..................................................................................21

4.2下弦杆节点连接螺栓数计算..............................................................................21

4.3上弦杆节点连接螺栓数计算..............................................................................22

第五章：节点板设计...................................................................................................23

5.1下弦节点E₄计算.................................................................................................23

5.2下弦节点E₃的计算.............................................................................................25

5.3下弦端节点E₀的计算.........................................................................................25

5.4下弦节点处与下平纵联相连增设的节点板计算..............................................27

5.5上弦节点A₅计算.................................................................................................28

5.6上弦节点A₄计算.................................................................................................30