钢箱梁横隔板-U肋疲劳裂纹钢板加固参数分析

针对疲劳裂纹建立局部有限元模型,分析钢板加固机理,通过提取连接焊缝焊趾应力评价受损构件钢板加固效果,针对胶层应力分析钢板加固胶层破坏模式,提取裂纹尖端应力强度因子用于研究钢板加固效果。通过设置多种工况,研究加固件面积、形状、厚度等参数对于加固效果的影响。研究表明：针对横隔板弧形缺口-U肋焊缝细节,钢板加固可改善应力水平。钢板可直接贴合加固裂纹,加固作用体现为代替受损截面参与构件协同受力。钢板加固范围对于加固效果影响较大,沿连接焊缝方向延长加固件,可提升加固效果,短裂纹加固时适当增加板厚,设置十字形加劲肋加固效果劣于等效增加板厚。

Parameters and effect analysis of steel box girder diaphragm-U rib fatigue crack plate reinforcement

A local finite element model was established for fatigue cracks to analyze the steel plate reinforcement mechanism. The steel plate reinforcement effect of damaged components was evaluated by extracting the stress of weld toe. The failure mode of steel plate reinforcement was analyzed for the adhesive layer stress. The stress intensity factor at the crack tip was extracted to study the steel plate reinforcement effect. By setting a variety of working conditions, the influence of reinforcement area, shape, thickness and other parameters on the reinforcement effect is studied. The research shows that the steel plate reinforcement can improve the stress level for the details of the arc notch-U rib weld of the diaphragm. The steel plate can be directly bonded to the reinforcement crack, and the reinforcement effect is reflected in replacing the damaged section to participate in the collaborative force of the component. The reinforcement range of steel plate has a great influence on the reinforcement effect. The reinforcement effect can be improved by extending the reinforcement parts along the direction of the connection weld. When short cracks are reinforced, the thickness of the plate is appropriately increased, and the reinforcement effect of setting cross stiffeners is inferior to that of equivalently increasing the thickness of the plate.