STUDY ON MECHANICAL PROPERTIES OF STUD SHEAR CONNECTORS IN STEEL-UHPC COMPOSITE STRUCTURES

In order to further study the mechanical properties and failure modes of studs embedded in ultra-high performance concrete (UHPC) and normal concrete (NC), a total of eight stud push-out specimens were tested and the influences of concrete type, diameter and length of stud on ultimate shear capacity were discussed. Based on the finite element model, the effects of ultimate tensile strength, diameter and length diameter ratio of stud and concrete strength on shear performance were further analyzed. The effects of diameter and length of stud and concrete strength on the effective distribution length of shear stress of stud were studied. The results show that the shear fracture near stud roots is the leading dominant failure mode. The shear capacity and shear stiffness of studs embedded in UHPC are higher than that of ordinary concrete, but the ductility is lower. The shear stress of stud peaks at the root and decreases rapidly along the direction of the nail cap. The diameter of stud has a significant effect on the effective distribution length of shear stress. Finally, according to the test results, the load-slip curve and a formula for the calculation of shear capacity under the stud shear failure mode are put forward, and the calculated results are in a good agreement with the test results, which can provide a reference for pertinent engineering design.