Tensile capacity of stud connectors under global bending: Experiments and FEM

Abstract In actual engineering practice, the uplift behavior of stud connectors in composite beams is significantly influenced by beam bending deformation. Therefore, this study examines the failure process and the ultimate bearing capacity of stud connectors embedded in beams were discussed through tests on beam specimens and finite element models (FEMs). A total of six composite beam specimens were designed and conducted uplift tests. Test results showed that all specimens failed due to concrete cone failure. Based on the correlation curves of the relative displacement ( s ) between the stud connector and beam versus load ( N ), the damage process was categorized into three stages: the elastic stage, the damage development stage, and the accelerated damage stage. Notably, in the damage development stage, it was observed that the stud root could not effectively transfer the external load. This was due to beam bending cracks which invalidated the bond between the stud root and its surrounding concrete. Consequently, an effective stud embedded height ( h ′ ef ) was introduced to quantify this adverse effect of beam bending. Furthermore, a validated FEM was used for parametric analyses. Results indicated that h ′ ef was the critical factor in determining the final concrete failure cone, and the ratio of the original stud embedded height ( h ef ) to the beam height ( h ) had a significant effect on h ′ ef . Based on the analysis results and the concrete capacity design (CCD) model, a modified bearing capacity calculation method incorporating the beam bending effect was proposed, which could predict the tensile behavior of the stud connector in composite structures more accurately.