正交异性钢桥面板U肋-盖板焊接节点的疲劳性能试验
发布时间：2018-10-16 09:16
【摘要】：为深入研究正交异性钢桥面板U肋-盖板焊接节点的疲劳性能及其破坏机理,设计了6个足尺试件模型开展试验研究。首先进行中心加载和偏心加载两种加载工况下的静力试验,对焊缝附近区域的钢板表面应力进行实测,得到热点应力分布规律及应力集中系数;随后进行不同热点应力幅下的高周疲劳循环加载,得到相应的疲劳破坏模式、疲劳寿命、疲劳裂纹扩展过程及速率、刚度退化等实测数据。结果表明:U肋-盖板焊接节点的最大热点应力位于盖板焊趾处;节点在循环荷载作用下的疲劳裂纹扩展过程大致分为裂纹萌生、裂纹稳定扩展、裂纹贯穿壁厚、断裂失效4个阶段,且裂纹贯穿盖板壁厚之后的剩余疲劳寿命可忽略不计;疲劳开裂初期的裂纹扩展速率较为稳定,裂纹贯穿盖板厚度之后的扩展速率明显加快;节点刚度在裂纹长度达到150 mm时开始出现下降趋势,并在裂纹贯穿盖板厚度之后发生刚度急剧退化。通过疲劳寿命数据对比,可以认为采用IIW规范的FAT100级S-N曲线对正交异性钢桥面板U肋-盖板焊接节点的疲劳寿命进行预测和评估是偏于安全的。
[Abstract]:In order to study the fatigue behavior and failure mechanism of U-rib-cover welded joints of orthotropic steel bridge panel, six full-scale specimen models were designed to carry out experimental research. Firstly, the stress of steel plate near the weld is measured by static test under central and eccentric loading conditions, and the stress distribution law and stress concentration factor of hot spot are obtained. The fatigue failure mode, fatigue life, fatigue crack propagation process and rate, stiffness degradation and so on are obtained by high cycle cyclic loading under different hot stress amplitudes. The results show that the maximum hot stress of the welded joint is located at the toe of the cover plate, and the fatigue crack propagation process of the joint under cyclic load is roughly divided into crack initiation, crack stable growth and crack thickness through the wall. The residual fatigue life of the crack passing through the wall thickness of the cover plate is negligible, and the crack propagation rate at the initial stage of fatigue cracking is relatively stable, and the propagation rate of the crack after the crack passing through the thickness of the cover plate is obviously accelerated. The stiffness of the joints began to decrease when the crack length reached 150 mm, and the stiffness decreased sharply after the crack penetrated through the slab thickness. Based on the comparison of fatigue life data, it is considered that it is safe to predict and evaluate the fatigue life of welded joints of orthotropic steel bridge panel U-ribbed slab by FAT100 S-N curve of IIW code.
【作者单位】： 上海交通大学船舶海洋和建筑工程学院;中交公路规划设计院有限公司;
【基金】：上海市自然科学基金项目(14ZR1422800) 中国铁路总公司科技研究开发计划项目(2014G010-F) 中央级公益性科研所基本科研业务费专项资金项目(2015-9020)
【分类号】：U441.4;U445.583
，
本文编号：2273905
[Abstract]:In order to study the fatigue behavior and failure mechanism of U-rib-cover welded joints of orthotropic steel bridge panel, six full-scale specimen models were designed to carry out experimental research. Firstly, the stress of steel plate near the weld is measured by static test under central and eccentric loading conditions, and the stress distribution law and stress concentration factor of hot spot are obtained. The fatigue failure mode, fatigue life, fatigue crack propagation process and rate, stiffness degradation and so on are obtained by high cycle cyclic loading under different hot stress amplitudes. The results show that the maximum hot stress of the welded joint is located at the toe of the cover plate, and the fatigue crack propagation process of the joint under cyclic load is roughly divided into crack initiation, crack stable growth and crack thickness through the wall. The residual fatigue life of the crack passing through the wall thickness of the cover plate is negligible, and the crack propagation rate at the initial stage of fatigue cracking is relatively stable, and the propagation rate of the crack after the crack passing through the thickness of the cover plate is obviously accelerated. The stiffness of the joints began to decrease when the crack length reached 150 mm, and the stiffness decreased sharply after the crack penetrated through the slab thickness. Based on the comparison of fatigue life data, it is considered that it is safe to predict and evaluate the fatigue life of welded joints of orthotropic steel bridge panel U-ribbed slab by FAT100 S-N curve of IIW code.
【作者单位】： 上海交通大学船舶海洋和建筑工程学院;中交公路规划设计院有限公司;
【基金】：上海市自然科学基金项目(14ZR1422800) 中国铁路总公司科技研究开发计划项目(2014G010-F) 中央级公益性科研所基本科研业务费专项资金项目(2015-9020)
【分类号】：U441.4;U445.583
，
本文编号：2273905
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