Structural performance of rail connections: Experimental testing and finite element modeling

• Full-scale three-point bending tests were conducted on UIC 60 rail connections. • Bolted, welded, and hot-rolled rails were compared in terms of stiffness and deflection. • Finite element models were developed in ANSYS R2 2023 and validated with experiments. • Welded joints closely replicated the performance of standard one-piece rail sections. • Bolted joints showed reduced stiffness and stress concentration near bolt interfaces. Rail joint performance plays a vital role in ensuring the safety, durability, and structural integrity of railway systems. Among the commonly used connection types; hot-rolled, bolted, and welded—each exhibit distinct mechanical behavior under operational loading conditions. This study presents an integrated experimental and numerical investigation into the flexural response of UIC 60 rail connections subjected to three-point bending. Full-scale laboratory tests were conducted to examine the load–deflection behavior, stiffness, and deformation capacity of the rail joints under static loads reaching 1400 kN. Experimental results revealed that both hot-rolled and flash-butt welded specimens demonstrated high stiffness and consistent load-bearing capacity, while bolted joints exhibited lower stiffness and increased deflection, attributed to stress concentrations near bolt regions and plate interfaces. Finite element simulations using ANSYS R2 2023 were performed to replicate the experimental setup and evaluate internal stress states. Numerical models showed strong agreement with the experimental results in the elastic range and highlighted differences in stress distribution between joint types. Welded joints exhibited continuous stress flow across the weld interface, while bolted connections showed localized stress peaks. The results confirm that welded joints offer structural continuity nearly equivalent to monolithic rails, whereas bolted joints are more susceptible to higher localized deformation and stress concentrations under bending.