Ductility and stiffness of shear studs in deck slab ribs transverse to beams for design according to Eurocode 4

The ductility and stiffness of shear connectors are critical to the performance and resistance of steel-concrete composite structures. This paper proposes empirical models for predicting the slip capacity, elastic slip, and shear stiffness of headed studs embedded in deck slab ribs oriented transversely to beams. The proposed stud deformation models apply to the resistance model from the second generation of Eurocode 4 (prEC4) and the models previously proposed by the authors (DH and modified DH). Developed through regression analyses of a test database compiled in the study, the models are functions of stud shank diameter, concrete compressive strength, normal force on the slab surface, longitudinal distance from rib top corner to nearest stud, ultimate tensile strength of the steel stud, transverse and longitudinal stud spacing within the rib, stud welding type, number of studs per rib, and stud height-to-diameter ratio. Characteristic values of the deformation predictions were derived in accordance with EN 1990, as required by prEC4. The influence of shear connection parameters on ductility and stiffness was evaluated for deck profiles commonly used in Europe. This is the first study to propose and calibrate design models for slip capacity, elastic slip, and shear stiffness of studs in deck slabs in accordance with the Eurocodes, enabling the characteristic deformation properties to be calculated without the need for physical testing. The findings support more efficient and reliable design practice, thereby enhancing both the safety and economy of composite floor systems.