【作者】 王策；

【导师】 黄平明； 梅葵花；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2011， 硕士

【摘要】 随着碳纤维复合材料(CFRP)的在桥梁中的应用研究,其在超大跨悬索桥中的优势日益受到人们的重视。然而,国内外尚无此类桥梁建成,在初步设计时,没有具体的结构尺寸以及相互之间的关系可以借鉴,所以进行优化设计是很有必要的。本文仅对CFRP缆索悬索桥的一些基本尺寸参数对结构的静力性能和自振特性的影响进行了对比分析,然后通过零阶优化法和一阶优化法对其进行静力优化研究,以期得到合理的构造尺寸。本文首先介绍了碳纤维复合材料(CFRP)的基本力学性能,系统地阐述了悬索桥计算理论,包括弹性理论、挠度理论以及有限位移理论为悬索桥的静、动力分析提供理论基础,还介绍了结构优化设计理论,包括它的分类、一般数学模型和算法。其次,对CFRP缆索和钢缆索两种结构的理论极限跨径进行了对比,采用ANSYS软件建立有限元模型,对CFRP缆索悬索桥和钢缆索悬索桥分别进行恒载、汽车荷载以及温度作用的对比分析计算,得出在这些工况下,二者的力学性能差异。然后,采用参数化有限元法(APDL)建立主跨2000m的三跨连续CFRP缆索悬索桥,并调整不同的参数,对比其在不同参数下的静、动力性能,分析这些参数对结构性能的影响。主要参数包括主缆尺寸、主缆垂度以及边中跨比。最后,详细介绍了优化设计的方法和步骤,并采用零阶优化法和一阶优化法对此悬索桥进行了静力性能优化,并对优化前后的模型进行了静、动力性能对比分析,为超大跨悬索桥的优化提供一些具有一定参考价值的结论。更多还原

【Abstract】 With the application study of the carbon fiber reinforced polymer (CFRP) in bridge structure, the superiority that CFRP is applied to super-span suspension bridge is increasingly highlighted for special attention to designer. However, there is none this kind of bridge completed both at home and abroad, and there is no detailed and exact construction size to use for reference in preliminary design stage, so it is necessary to make optimum design. Some influences of fundamental parameters on static and free vibration characteristics of suspension bridges with CFRP cables are analyzed comparatively, then optimum design of static characteristics by zero-order optimization method and first-order optimization method is carried out in this article to expect obtaining the reasonable construction size.Firstly, the mechanical characteristics of CFRP and the calculation theories of suspension bridges, including elastic theory, deflection theory and finite displacement theory are introduced systematically in this article, which provides theoretical basis for the analysis of static and dynamic characteristic of suspension bridges. Besides, the construction optimum design theory including its categories, general mathematics model and mathematics is also introduced.Secondly, the theoretic limitation span of continuous suspension bridges with CFRP cables or steel cables are compared. The performances of both bridges are calculated and analyzed comparatively by making use of ANSYS, when they are under dead load, vehicle load and temperature load separately. Then, the differences mechanical properties of them in these working conditions are arrived.Thirdly, the static and dynamic performances of the 2000m-span and three-span continuous suspension bridges with CFRP cables are compared by making use of the ANSYS Parametric Design Language (APDL) through changing different parameters. The influence of these parameters are analyzed.The main parameters include the size and the sag of main cable, the ratio of side span to middle span.Finally, the methodology and procedure of optimum design are detailed introduced, and the optimum design of static characteristics for suspension bridges making use of zero-order optimization method and first-order optimization method is carried out in this article. The static and dynamic characteristic of suspension bridges before and after optimum are analyzed comparatively, to provide a certain valuable conclusion to the optimum design of super-span suspension bridge.更多还原