# Numerical Investigation on Novel Shear Connectors in Prefabricated Composite Beams
## 2 Push-Out Test for Shear Performance Analysis
### Shear Capacity and Slip Characteristics  
The test results of the HS14 specimens and VS4 specimens were analyzed after all the specimens had failed. In order to facilitate the comparison of the two types of specimens, the test results are listed in Table 3, including the maximum bearing capacity value \(P_{u}\), the value of the slip under the load of \(P_{u}\), the ductility test value, and the failure mode. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **Stud** & \multicolumn{3}{c}{**Steel Plate**} & \multicolumn{3}{c}{**Rebar**} \\ \hline \(E_{s}\) (GPa) & \(\sigma_{y}\) (MPa) & \(\sigma_{us}\) (MPa) & \(E_{s}\) (GPa) & \(\sigma_{y}\) (MPa) & \(E_{s}\) (GPa) & \(\sigma_{y}\) (MPa) \\ \hline
205 & 340 & 400 & 210 & 412 & 209 & 458 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Steel material properties. Figure 3: Test set up and instrument: (**a**) photograph; (**b**) schematic view. The test results show that the failure modes of the two types of specimens were all shear stud shank failure. The maximum shear capacity of the prefabricated shear studs is higher than that of the conventional shear studs, according to the comparison analysis. The shear capacity value of the smallest (HS14-2; 43 kN) of the prefabricated shear studs is 15% larger than the maximum shear capacity value (VS4-1; 37.38 kN) of the conventional shear studs. On the contrary, the slip value, \(S_{Pu}\), of the VS4 specimens under the load of \(P_{u}\) is a little larger than that of the HS14 specimens, as shown in Table 3. The ductility of the two specimens was also tested, the ductility value, \(S_{d}\), is selected when the load value is decreased by 10%, which is also the test termination condition of this test. The test ductility value shows that the ductility ratios of the prefabricated shear studs are better than those of the conventional shear studs. In addition, the minimum ductility value of the HS14 specimens (2.75 mm) is 36.8% larger than the maximum ductility of the VS4 specimens (2.01 mm). Finally, the HS style studs' ultimate load capacity is at least 1.19 times greater than the VS style studs, and their ductility is at least 1.36 times greater than the VS style studs. Figure 4 shows that the load-slip behavior of the two types of specimens generally follow three stages. Stage I: the amount of slip is tiny increased. Stage II: the slip increases in a nonlinear positive fashion before the curve's peak with load growth, while the load growth rate exceeds the slip increase rate. Stage III: the slip grows rapidly while the load decreases gradually after the curve's peak, and the rate of slip growth is far greater than the reduction rate of the load. The two types of specimen follow the same slip law, and the slope of the curve can reflect the specimen's stiffness and ductility. The stiffness is almost the same during stage I,  
Figure 4: Load–slip curves of the specimens. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Specimen**} & **Ultimate** & **Slip** & **90\% Ultimate** & \multirow{2}{*}{**Test Ductility,**} & **Failure** \\  & **Strength per** & **Values** & & **Strength per** & \(S_{d}\) (mm)** & **Mode** \\  & **Stud, \(P_{u}\) (kN)** & \(S_{Pu}\) (mm)** & **Stud** 0.9 \(P_{u}\) (kN)** & & \\ \hline VS4-1 & 37.38 & 1.17 & 33.64 & 2.01 & shank failure \\ VS4-2 & 35.25 & 1.13 & 31.73 & 1.76 & shank failure \\ VS4-3 & 32.63 & 1.20 & 29.36 & 1.96 & shank failure \\ HS14-1 & 44.44 & 0.97 & 39.99 & 2.75 & shank failure \\ HS14-2 & 43.00 & 1.02 & 38.70 & 3.21 & shank failure \\ HS14-3 & 43.13 & 0.97 & 38.81 & 2.81 & shank failure \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Test results of the specimens. where the curve's positive rate of the two types of specimens is only slightly different. However, the specimen stiffness of the HS14 samples is larger than for the VS4 samples so the curve's positive rate of the HS14 samples is larger than for the VS4 samples during stage II.