正交异性钢桥面板疲劳裂纹试验和数值分析

发布时间：2018-03-10 11:11

本文选题：正交异性钢桥面板　切入点：节段模型　出处：《桥梁建设》2017年05期 　论文类型：期刊论文

【摘要】：横隔板开孔和U肋与横隔板连接焊缝端头部位是正交异性钢桥面板的疲劳敏感部位,容易过早、过多地出现疲劳裂纹。为了研究疲劳裂纹产生的原因,以某钢箱梁悬索桥为背景,针对其正交异性钢桥面板制作节段模型进行疲劳试验和扩展有限元分析,考虑横隔板面外变形的影响,研究横隔板开孔部位、U肋与横隔板连接焊缝端头部位疲劳裂纹的产生和扩展。结果表明:节段模型经200万次疲劳荷载作用后,横隔板开孔处出现长7.5mm的裂纹,260万次后扩展到31mm;考虑顶板和横隔板之间的相对水平位移(1.21mm)时,各测点的面内应力计算值与实测值整体吻合良好;横隔板开孔断面最小处的应力达60 MPa,热点应力达到或超过该细节的常幅疲劳极限70MPa,在此处产生裂纹;横隔板的面外变形是诱发横隔板开孔处裂纹的根本原因,热点应力和结构缺陷促使了裂纹的产生。
[Abstract]:In order to study the cause of fatigue crack, the open hole of transverse diaphragm and the end part of weld joint between U rib and transverse partition board are the fatigue sensitive parts of orthotropic steel bridge panel. Taking a steel box girder suspension bridge as the background, the fatigue test and extended finite element analysis are carried out for the segment model of orthotropic steel deck slab. The fatigue crack generation and propagation at the end of weld joint between U rib and transverse partition at the open hole of the transverse partition are studied. The results show that the segment model is subjected to 2 million fatigue loads. A crack of 7.5 mm in length appeared in the opening of the transverse diaphragm, which was extended to 31 mm after 2.6 million times. When the relative horizontal displacement between the roof and the transverse partition was taken into account (1.21 mm), the calculated values of in-plane stress at each measuring point were in good agreement with the measured values. The stress at the minimum section of the transverse diaphragm is up to 60 MPa, and the hot spot stress reaches or exceeds the constant fatigue limit of 70 MPa in this detail, resulting in a crack here, and the out-of-plane deformation of the transverse diaphragm is the fundamental cause of the crack at the opening of the transverse partition. Hot spot stress and structural defects promote the generation of cracks.
【作者单位】：重庆交通大学土木工程学院;山区桥梁结构与材料教育部工程研究中心;
【基金】：国家自然科学基金项目(51478071)~~
【分类号】：U441.4

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