新型镦边U肋正交异性钢桥面板疲劳性能研究
发布时间：2018-08-18 10:25
【摘要】：正交异性钢桥面板发展面临的主要问题在于良好的受力性能与高疲劳病害风险之间的矛盾,其中顶板与纵肋焊接构造细节是正交异性钢桥面板疲劳病害危害最为严重的部位之一。从传统正交异性钢桥面板本身结构体系出发来改善其疲劳性能,虽然取得了一定的进展,但这一部位的疲劳病害案例仍然不断涌现。在传统正交异性钢桥面板的基础上,通过改进创新得到的结构形式来改善结构的疲劳性能,是促进正交异性钢桥面板应用并推动其可持续发展的可行途径之一。以新型镦边U肋正交异性钢桥面板为研究对象,开展了以下几个方面进行研究工作:(1)简要概述了正交异性钢桥面板的发展历程,疲劳问题的产生原因及疲劳分析的基本理论和相关基本概念。介绍了新型结构的研究现状,引入新型镦边U肋正交异性钢桥面板,阐述了其提出背景和设计理念。(2)对缺口应力法进行了全面的介绍,详细阐述了缺口应力法的理论基础,总结了缺口应力法的特点及与名义应力法、热点应力法的异同。讨论了影响缺口应力法的关键因素:疲劳缺口系数,疲劳寿命曲线以及缺口应力求解方法。(3)分析正交异性钢桥面板各构造细节参数对缺口应力及疲劳缺口系数的影响,结果表明:增大顶板厚度可以有效改善顶板与纵肋焊接构造细节各疲劳关注细节的应力集中情况,增大U肋厚度主要减小U肋焊趾处应力,开口角度对顶板焊趾处应力影响最显著,而增大焊缝熔深对焊根处应力集中有所改善。相关结论可为提高钢桥面板的疲劳性能作参考。(4)对顶板与纵肋焊接构造细节已有疲劳试验的名义应力数据进行再分析,并转换为对应的缺口应力。结果表明缺口应力疲劳数据均位于ⅡW推荐的FAT225曲线之上,因此缺口应力法可以很好地应用在该构造细节的疲劳评价中。(5)采用缺口应力法对新型镦边U肋正交异性钢桥面板疲劳寿命进行了评估,并对相关关键问题进行了研究。结果表明:缺口应力可以作为焊根或焊趾疲劳性能的有效评估指标,判别其疲劳性能的差异,相对而言,焊根处更易萌生裂纹;新型镦边U肋相较于传统U肋,可以较好的改善该构造细节顶板焊趾及U肋焊趾处疲劳性能,但对焊根处应力改善效果不显著。
[Abstract]:The main problem in the development of orthotropic steel bridge is the contradiction between good mechanical performance and high fatigue risk. The structural details of roof and longitudinal rib welding are one of the most serious fatigue damage parts of orthotropic steel bridge panel. Although some progress has been made in improving fatigue performance of orthotropic steel bridge panels from the traditional structural system of orthotropic steel bridges fatigue disease cases in this area are still emerging. On the basis of the traditional orthotropic steel bridge panel, it is one of the feasible ways to promote the application of orthotropic steel bridge panel and promote its sustainable development to improve the fatigue performance of the structure by improving the structure form obtained by innovation. Taking the new upsetting U-rib orthotropic steel bridge face as the research object, the following aspects of the research work are carried out: (1) the development of orthotropic steel bridge panel is briefly summarized. The causes of fatigue problems and the basic theory and related concepts of fatigue analysis. This paper introduces the research status of the new structure, introduces the new upsetting U-rib orthotropic steel bridge panel, expounds its background and design idea. (2) the notched stress method is introduced comprehensively, and the theoretical basis of the notched stress method is expounded in detail. The characteristics of notch stress method and its similarities and differences with nominal stress method and hot stress method are summarized. The key factors affecting notch stress method, such as fatigue notch coefficient, fatigue life curve and notch stress solution method, are discussed. (3) the influence of structural detail parameters on notch stress and fatigue notch coefficient of orthotropic steel bridge face is analyzed. The results show that increasing the thickness of roof can effectively improve the stress concentration of fatigue detail of roof and longitudinal rib welding structure, and increase the thickness of U rib to decrease the stress at the toe of U-rib welding. The effect of the opening angle on the stress at the toe is the most significant, while the stress concentration at the root is improved by increasing the weld penetration. The relevant conclusions can be used as a reference for improving the fatigue performance of steel bridge slabs. (4) the nominal stress data of fatigue tests on the structure details of roof and longitudinal rib welding have been reanalyzed and converted into corresponding notch stresses. The results show that the notch stress fatigue data are above the FAT225 curve recommended by 鈪，
本文编号：2189177
[Abstract]:The main problem in the development of orthotropic steel bridge is the contradiction between good mechanical performance and high fatigue risk. The structural details of roof and longitudinal rib welding are one of the most serious fatigue damage parts of orthotropic steel bridge panel. Although some progress has been made in improving fatigue performance of orthotropic steel bridge panels from the traditional structural system of orthotropic steel bridges fatigue disease cases in this area are still emerging. On the basis of the traditional orthotropic steel bridge panel, it is one of the feasible ways to promote the application of orthotropic steel bridge panel and promote its sustainable development to improve the fatigue performance of the structure by improving the structure form obtained by innovation. Taking the new upsetting U-rib orthotropic steel bridge face as the research object, the following aspects of the research work are carried out: (1) the development of orthotropic steel bridge panel is briefly summarized. The causes of fatigue problems and the basic theory and related concepts of fatigue analysis. This paper introduces the research status of the new structure, introduces the new upsetting U-rib orthotropic steel bridge panel, expounds its background and design idea. (2) the notched stress method is introduced comprehensively, and the theoretical basis of the notched stress method is expounded in detail. The characteristics of notch stress method and its similarities and differences with nominal stress method and hot stress method are summarized. The key factors affecting notch stress method, such as fatigue notch coefficient, fatigue life curve and notch stress solution method, are discussed. (3) the influence of structural detail parameters on notch stress and fatigue notch coefficient of orthotropic steel bridge face is analyzed. The results show that increasing the thickness of roof can effectively improve the stress concentration of fatigue detail of roof and longitudinal rib welding structure, and increase the thickness of U rib to decrease the stress at the toe of U-rib welding. The effect of the opening angle on the stress at the toe is the most significant, while the stress concentration at the root is improved by increasing the weld penetration. The relevant conclusions can be used as a reference for improving the fatigue performance of steel bridge slabs. (4) the nominal stress data of fatigue tests on the structure details of roof and longitudinal rib welding have been reanalyzed and converted into corresponding notch stresses. The results show that the notch stress fatigue data are above the FAT225 curve recommended by 鈪，
本文编号：2189177
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