Fatigue repairing craftsmanship of deck-to-vertical stiffener weld in the steel bridge deck

Abstract

Experiments and FE analysis were conducted on the fatigue repairing techniques of deck-to-vertical stiffener weld in the steel bridge deck. The steel bridge deck was modeled to analyze cracking reason of deck-to-vertical stiffener weld. The fatigue repairing experiment was carried out on three repairing techniques. The fatigue life and stress distribution of the deck-to-vertical stiffener weld were analyzed and repairing effects were compared. Repairing craftsmanship with different parameters was modeled to study change of stress distribution. Besides, influence of welding residual stress, stop-hole and CFRP reinforcement on fatigue repairing was discussed. The results showed that cracks of welding end on the deck were induced by out of plane deformation while those on the vertical stiffener were caused by combined out-of-plane and in-plane deformation, which was more prone to cracking. Residual tensile stress reached yield strength of steel after re-welding, thus hammering and polishing after re-welding could improve fatigue life of the weld. The re-welding techniques had more favorable repairing effects than stop-hole and CFRP reinforcement.