碳纤维布加固钢箱梁的热点应力计算方法研究

Hot Spot Stress of Steel Box Girder Reinforced with Carbon Fiber Sheet

钢箱梁长期运营后,在纵肋与顶板的纵向连接焊缝处、横隔板弧形开口处、U肋和纵肋对接焊缝处不可避免地出现疲劳裂纹。疲劳裂纹的出现使得钢箱梁运营存在重大隐患,而碳纤维布加固是疲劳加固的一种较为有效的措施。根据江阴大桥节段式构件,采用碳纤维布不同的粘贴加固方式进行处理,并建立了碳纤维布加固钢箱梁的有限元计算模型,利用多种外推方法对焊接区域的热点应力进行了计算分析。对比发现,加固方式Ⅱ在达到加固效果的同时,还能够节约材料。

With the operations of steel box girder, fatigue cracks inevitably occur in the joint weld between longitudinal ribs and roof, arc-shaped opening in the crossbeam and butt weld which junction of U ribs and longitudinal ribs. There are significant risks on steel box girder after some fatigue cracks operators on it, thence it is a more effective measure by using CFRP reinforced. Establish sheet steel box girder finite element model which is reinforced by carbon fiber sheet in different paste process based on the Jiangyln Yangtze River Bridge segmental member. And a variety of extrapolation methods are used to calculate hot spot stress in weld area, showing that the reinforcement Ⅱ mean has perfect reinforced effect while can save strengthening materials.