【作者】 唐清华；

【导师】 郑史雄；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2005， 硕士

【摘要】 随着我国经济迅猛发展的需要,大跨径跨海工程已被提上议程。桥梁跨径的不断增大,使得桥梁结构在风荷载作用下的动、静力问题日益突出。目前,桥梁风工程界对大跨径桥梁的研究主要考虑动力稳定问题和振动响应问题,并取得了很大进展,而对空气静力问题的研究仍然欠缺。根据国内外风洞模型试验成果,大跨径桥梁发生静风稳定性问题的临界风速可能低于动力稳定的临界风速。另外,在强静风荷载作用下,大跨径桥梁的几何非线性、静风荷载非线性的影响均不容忽视。因此,对大跨径或超大跨径桥梁(尤其是悬索桥)的静风稳定性问题的研究是桥梁抗风性能研究的一个重要方向。基于此,本文对大跨径悬索桥结构的抗静风问题作了详细深入的研究,具体内容如下: 1、阐述了现行《公路桥梁抗风设计指南》中计算桥梁结构静风失稳临界风速的线性方法,并对求解结构扭转发散临界风速的计算公式做了简要的推导。 2、提出了基于ANSYS的计算大跨径桥梁静风稳定性的非线性有限元法,充分考虑了结构的几何非线性及静风荷载的非线性。 3、将非线性有限元法的计算结果与现行线性方法的计算结果作了详细的比较。经比较得出:用现行线性方法计算结构的静风稳定性会过高的估计结构的抗静风能力,偏于不安全;非线性有限元法计算结构的静风稳定性与线性方法相比更精确;非线性有限元法具有能跟踪结构失稳全过程的优点。 4、在保持其它设计参数不变的前提下,通过选取不同的风初始攻角、边跨跨径、中跨跨径、矢跨比、加劲梁截面形式、单位长度桥道质量及主塔高度等参数,分别用线性方法与非线性有限元法详细考察了大跨径悬索桥静风稳定性的影响因素,为大跨径桥梁的抗静风设计提供依据与参考。更多还原

【Abstract】 As the need of the rapid development of economy, the long-span transoceanic engineering is proposed. With the span of the bridge is become longer and longer, the static and dynamic problems of the bridge structure induced by wind are more and more serious. Nowadays, while studying the behavior of bridge under wind, more attention is focused on the problems of aerodynamic stability and vibration response which have been great progress. But aerostatic problem is still researched little. According to the results of the wind tunnel model tests domestic and abroad, the critical wind speed of the aerostatic stability of long-span bridge may be less than that of the aerodynamic stability. In addition, the effects of geometric nonlinearity and the aerostatic load nonlinearity of long-span bridges under strong wind load shouldn’t be neglected. The problems of the aerostatic stability of long-span and super long-span bridges, particularly the suspension bridges, are also crux. Therefore, the problems of aerostatic stability of long-span suspension bridge are detailedly and deeply studied in this thesis:1.The linear method being used to calculate the critical wind speed of aerostatic stability by national guideline is expatiated. And the briefly deduced formula is used to calculate the critical wind speed of torsional divergence.2.Based on ANSYS, the program used to calculate the critical wind speed of aerostatic stability, which can sufficiently consider the geometric nonlinearity and the aerostatic load nonlinearity, is presented.3. The results of the nonlinear finite element method are detailedly compared with that of the linear method being used by更多还原