Tensile resistance and shear-tension interaction relationship of T-type perfobond rid shear connectors

This study aims to investigate the mechanical performance of T-type perfobond rib (T-type PBL) shear connectors under complex load cases. Initially, the experimental tests were conducted and finite element analyses (FEA) were performed. Subsequently, a parametric study was carried out to assess the impact of geometric parameters on tensile resistance and the effect of tension ratio on the shear-tension interaction resistance of T-type PBL connectors. Finally, based on the test and FEA results, prediction methods were developed for evaluating the tensile resistance and shear-tension interaction relationship of T-type PBL connectors. The test results showed that the pull-out of the concrete below the flange led to the failure of T-type PBL shear connectors under tension. The concrete failure angles were approximately 33°. The failure under shear was manifested as concrete collapse and connector yielding. The ultimate capacity decreased with the increase in tension ratio. The specimens with tension ratios of 25%, 45%, and 65% decreased 7.9%, 16.3%, and 24.2%, respectively, compared to the specimen under pure shear. The parametric study suggested that the rib height and perforated rebars were the main factors impacting the tensile resistance of T-type PBL shear connectors. When the tension ratio reached 55% of the ultimate, the failure mode of the shear connectors was dominated by the pull-out of the concrete. The tensile resistance evaluation formula was verified by the test and FEA results, demonstrating an average calculated-to-FE-results ratio of 0.99 with a standard deviation of 0.04. The suggested shear and tension interaction relationship for T-type PBL connectors had reliable predictive outcomes, with a coefficient of variation of 0.02. This study could provide guidance for the design of T-type PBL shear connectors and promote the application in long-span composite structures.