Experimental research and numerical analysis of shearing resistance in steel-concrete composite beam connectors

Shear connectors are an essential part of steel-concrete composite beams and play a vital role in steel-concrete composite beams. Many failures are caused by unreliable connections, resulting in many casualties, property losses, or both. Most of the current research on shear connectors in composite specimens points to simultaneous stressing together of the shear connectors and concrete because the mechanical properties of shear connectors depend on factors such as concrete strength and embedded slenderness ratio. This paper proposes a novel bolted nail and its combined connector to negate the influence of the above factors on the shear stress connector's mechanical performance. Experimental research obtained the shear resistance, failure mechanism, and stress-strain properties of shear connectors. The comparative analysis of the bolt connectors and the standard stud connectors showed that the stud connectors began to deform when loaded to 64% of the bolted connector's ultimate capacity. Deformation occurred in bolted connectors at 56% of their utmost capacity. The root of the connectors first cracked when its included angle with the horizontal direction was about 45°. The stud connectors cracked at about 50° angle, and they possessed good shearing resistance and ductility. Compared with the bolted connectors, the bearing capacity and ultimate bearing capacity corresponding to the initial deformation of the stud connectors were relatively high; 27.68% and 12.07% higher than those of the bolted connectors, respectively. The stud connectors showed better ductility, deformation performance, and shearing resistance. The bolted connectors have better pull-out resistance and are also construction and installation-friendly, improving construction efficiency and ensuring effective connection. The research results directly serve actual projects and provide a reference for similar connectors' research.