The Research of Fatigue Test Design of Steel Box Girder Reinforced with CFRP Sheet

After a long-term operation of the steel box girder,it inevitably occurs in the appearance of fatigue crack, which may take the operation with a certain security risk.Repairing welding,hole drilling and CFRP reinforcement are the main methods to maintain fatigue crack of the steel box girder.Besides,CFRP reinforcement method makes full use of the advantage of composite materials,and it can be regarded as a more effective maintenance method.According to a segmental steel box girder component,the carbon fiber cloth reinforcement material is selected in five links which contain surface modi-fication,mixed gum,rubber coating,paste CFRP sheets and anchorage,are determined and the devices of fatigue test and the test schemes are designed.Through the fatigue test,it points out the fatigue performance of the strengthened members and the effect of the verified reinforcement,which leads to theoretical analysis of the evolution of fatigue damage.