Static behavior of stud connectors in bi-direction push-off tests

Headed stud shear connectors are commonly used to transfer longitudinal shear forces across the steel-concrete interface. In order to investigate the behavior of headed shear stud connectors, bi-direction push-off tests were conducted. Eighteen specimens, including six forward and twelve inverse push-off specimens, were tested to evaluate the failure modes, bearing capacity and load-displacement relationship of studs. An accurate numerical model was developed and validated against the experimental results, and based on which extensive parametric studies were performed to investigate the variation in concrete strength, stud yield strength, stud diameter and length-to-diameter ratio of stud on the structural performance. Based on the experimental and numerical results, new design equations of stud shear capacity and stud load-slip relationship were proposed and compared with the current code of practices GB 50017-2003, AISC, EN 1994-1-1, and relevant references. Comparing to the existing approaches, the proposed formulas have a better match with the experimental values.