Shear behavior of short stud in I-beam-ultra-high performance concrete (UHPC) composite structure

As the connecting component of I-beam and UHPC, the stud is the basis of the cooperative work of each component, and is crucial to the stability and safety of the structure. To further study the shear behavior of studs in I-beam-UHPC composite structures, the push-out test was carried out by numerical simulation. The numerical simulation is in line with the load-relative slip curve and failure mode obtained by the experiment, verifying the accuracy of the numerical model. On the basis of verifying the model, the influences of the diameter, height and ultimate tensile strength of the stud on the relative slip curve, shear strength, yield strength and shear stiffness of the stud are studied. The findings indicate that a stud with a diameter of 22 mm exhibits a shear strength 156% greater than that of a stud with a diameter of 10 mm. Additionally, the yield strength increases by 135%, and the shear stiffness by 160 kN, highlighting the significant impact of stud diameter on shear resistance. When the ratio of length to diameter is less than 2.7, the shear strength of the stud increases with the height of the stud. The shear strength of a stud with a length-to-diameter ratio of 2.7 is 35% higher than that of a stud with a ratio of 1.5. The ultimate tensile strength of the stud ranges from 360 to 510 MPa, with only an 11 kN increase in yield strength, indicating that the ultimate tensile strength has a limited influence on shear properties. As the height of the stud decreases, its ultimate tensile strength gradually increases, bringing the numerical model closer to the predicted values. For shorter studs with higher ultimate tensile strength, the finite element simulation results are closer to the predicted values.