Fatigue performance of crossbeam‐to‐stiffener welded details adopted in OSD bridges

Abstract

Orthotropic Steel Decks (OSDs) are extensively employed in bridge engineering for medium‐ to long‐span viaducts, primarily due to their high strength‐to‐weight efficiency and the reduced need for additional reinforced concrete components. However, the large number of welded joints, combined with the significant influence of cyclic loading makes these structures particularly susceptible to fatigue‐related problems, which must be carefully addressed during the design phase. In this context, it is noteworthy that the upcoming 2nd generation of Eurocode 3 Part 1‐9 (EN1993‐1‐9:2025) will introduce updated provisions for the advanced fatigue evaluation of such structural details. Accordingly, this study investigates fatigue performance of crossbeam‐to‐stiffener welded joints extracted from a real case study, i.e., by applying multiple analytical approaches (nominal stress method, hot‐spot stress method, and strain energy density method). Obtained results are systematically compared and employed for a parametric optimization of key design parameters, e.g., plates' thickness and spacing.