Fatigue behavior and remaining life evaluation of rib-to-deck joints using interior repair welds

The rib-to-deck joints are one of the most critical vulnerable details of orthotropic steel deck subjected to vehicle loads. Specially, fatigue cracks initiating from the weld root and propagating along the thickness of the deck at the rib-to-deck joints is most difficult to repair. In this study, the interior repair weld is adopted to enhance the fatigue resistance of rib-to-deck joint. Three specimens of rib-to-deck joint were designed and tested to investigate the effectiveness and applicability of the interior repair weld. The fracture mechanics method associated with numerical simulation is adopted to analyze the failure mechanism and remaining life of rib-to-deck joints after reinforcement. The results indicate that the region of fatigue crack initiation will be transferred from the interior weld root before repairing to the exterior weld toe after repairing. The interior repair weld can effectively prevent fatigue crack propagation and significantly improve the remaining fatigue life of the rib-to-deck joints. The simulated fatigue life agrees well with the measurement in fatigue tests, revealing the accuracy of fracture mechanics method to estimate the remaining life.