Investigations on the shearing performance of composite beams with group studs

Steel-concrete composite beams are widely used in building structures due to the excellent mechanical performances. In the application of steel-concrete composite beam, the problem exists in the coordination between concrete slab and steel beam. In this work, based on the Eurocode-4, a series of four 1:1 full-size push-out specimens were designed to study the influence of different napping arrangement styles on the shear performance of the napping joints in the cast-in-place specimens and prefabricated specimens. Based on the test results, finite element analysis was finished for parametric analysis. The test results show that the final failure modes of the specimens include concrete failure and bolt shear. Increasing the concrete grade of the precast specimen can improve the shear resistance of the bolt group. The uniformly arranged specimens show higher shear stiffness and ductility compared to the non-uniformly arranged specimens. The results of finite element analysis showed that the shear capacity of the group nails was increased with the increase of the compressive strength grade of the post-pouring material and the longitudinal spacing of the bolts, and the increase of the spacing of the bolts was more effective in improving the shear capacity of the group nails.