Multi-Dimensional Influence Surface-Based Analysis on Fatigue Strength of Semi-Open-Rib to Deck Welded Joints in OBD

In this study, the fatigue strength of newly developed semi-open-rib-to-deck welded joints in orthotropic steel bridge decks (OBD) structures is accurately predicted using the traction structural stress method through comparison with full-scale experimental results. Three commonly adopted welded joints, i.e., semi-open-rib-to-deck, double-sided U-rib-to-deck, and open-rib-to-deck welded joints, are systematically compared to identify the best type. The critical fatigue strengths of semi-open-rib-to-deck and double-sided U-rib-to-deck welded joints are found to be nearly identical despite exhibiting distinct fatigue failure modes and significantly superior to open-rib-to-deck welded joints. Furthermore, a concept of the multi-dimensional influence surface is proposed for determining the critical fatigue failure mode subjected to random vehicular loads.