【作者】 成锋；

【导师】 王春生；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2010， 硕士

【摘要】 如何确保钢桥的疲劳使用安全一直是桥梁工程界关注的重要研究课题。早期建造的钢桥,由于当时焊接施工水平不高,设计者对疲劳的认识和考虑亦不充分,导致钢桥疲劳开裂问题十分严重。美国里海大学的最新研究结果表明钢桥中的疲劳裂纹90%为面外变形疲劳裂纹,而面外变形疲劳中有很大一部分是由于腹板间隙面外变形而造成的疲劳开裂。本文参考国内外钢桥腹板间隙面外变形疲劳的文献,利用有限元数值分析方法,针对直桥、弯桥和斜桥三种典型桥梁分别分析了结构中腹板间隙面外变形疲劳的受力行为,并对各个桥型的关键影响因素进行了参数分析,从而确定控制腹板间隙面外变形疲劳的主要结构参数,同时探究了钢桥腹板间隙面外变形的维修策略。本文的主要研究工作如下：1.总结了国内外有关钢桥腹板间隙面外变形疲劳问题及其维修策略的研究成果和研究方法。2.针对几种典型桥梁分别建立了三维有限元数值分析模型对钢桥腹板间隙面外变形疲劳进行分析,探讨不同桥型下钢桥腹板间隙面外变形疲劳行为的差异性。3.根据几种典型桥梁下产生不同的面外变形应力,分别进行了参数分析,研究间隙大小、腹板厚度、横撑刚度、横撑类型、桥梁跨径、弯桥的曲率半径以及斜桥的斜交角等关键结构参数,对腹板间隙面外变形应力值的影响,从而确定控制腹板间隙面外变形疲劳的主要结构参数。4.结合钢桥面外变形疲劳行为的有限元分析以及参数分析结果,研究了钢桥腹板间隙面外变形疲劳问题的维修加固方法,对进一步的维修加固提出了建议。更多还原

【Abstract】 How to ensure the fatigue use safe has been an important research topic concerned by bridge engneering. Steel bridge constructed ealier, because of low level of welding at that time, designers didn’t understand and consider fatigue sufficiently, thus fatigue cracking in such steel bridges is a serious problem. American researchers estimated that 90% of all fatigue cracking is the result of out-of-plane distortion at fatigue sensitive details of existing steel bridges. And the fatigue cracking caused by web gap out-of-distortion is the large part of out-of-distortion fatigue in steel bridge.Reviewd the documents about web gap out-of-plane distortional fatigue in steel bridges at home and abroad, this paper analysed the fatigue details of out-of-plane distortional fatigue in straight bridge, curved bridge and skewed bridge, and the parametric analysis aimed at different type bridge is developed to study key parameters which take control of web gap out-of-distortion, at the same time, study the maintenance and strengthening strategy for web gap out-of-distortion. In this thesis, the following aspects are investigated:1. Research result and method of web gap out-of-distortional fatigue at home and abroad was summarized.2. Analysis with 3-D finite element models according to some typical bridges was developed to discuss the difference among the web gap out-of-distortional fatigue behavior under different bridge structures.3. Parametric analysis for different bridge structures were carried out to study key structural parameters, such as web gap size, web thickness, stiffness of cross frame, type of cross frame, bridge span, radius of curvature of curved bridge, skew angle and so on, so as to make sure the key parameters which take control of web gap out-of-distortion.4. Combine the out of distortional fatigue behavior and parametric analysis results, maintenance method on web gap out-of-distortional fatigue was investigate, and the further maintenance strategy was proposed.更多还原