## 3 Experimental Results and Discussions
### Strength and Ductility  
The experimental hysteretic curves of the three tested bents are shown in Figure 8. For the convenience of observation, only the hysteretic curve for the first loading loop at the same displacement amplitude is given in the figure.  
Figure 8: Hysteretic curves of the bent specimens.  
Figure 7: Failure patterns of bent B2-PGT.  
Based on the above hysteretic curves, the skeleton curves of bent specimens can be obtained by connecting the vertices on the hysteretic curves at each displacement amplitude; see Figure 9. Meanwhile, the strength and lateral displacement corresponding to yield point, peak point, and ultimate point are summarized in Table 4.  
The peak point represents the point of peak lateral strength, and the ultimate point is defined as the point where the lateral strength drops to 85% of the peak strength. The yield point is defined using [PERSON]'s method [38], as shown in Figure 10. The skeleton curve in Figure 10 was obtained by taking the absolute mean value of the complete skeleton curve in Figure 9.  
Draw a horizontal line passing through the skeleton curve's peak point 'A' to determine the peak lateral strength \(F_{p}\). Subsequently, draw a horizontal line at 0.75 \(F_{p}\)  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Bent**} & \multicolumn{2}{c}{**Yield Point**} & \multicolumn{2}{c}{**Peak Point**} & \multicolumn{2}{c}{**Ultimate Point**} & \multirow{2}{*}{\(\
u\)=\(\delta_{u}/\delta_{y}\)} \\ \cline{2-2} \cline{5-8}  & \(\delta_{y}\) **(mm)** & \(F_{y}\) **(kN)** & \(\delta_{p}\) **(mm)** & \(F_{p}\) **(kN)** & \(\delta_{u}\) **(mm)** & \(F_{u}\) **(kN)** \\ \hline B2-CIP & 18.05 & 683.27 & 50.00 & 810.30 & 68.37 & 688.76 & 3.79 \\ \hline B2-PGS & 20.09 & 612.88 & 35.00 & 698.84 & 67.85 & 594.01 & 3.38 \\ \hline B2-PGT & 23.42 & 711.96 & 55.00 & 853.86 & 83.62 & 725.78 & 3.57 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Comparisons of performance variables.  
Figure 10: Equivalent yield displacement determined with [PERSON]’s method.  
Figure 9: Skeleton curves of tested bents.  
intersecting the skeleton curve at point 'B'. Then, draw a line from the origin 'O' to point 'B' and extend it until it intersects with the first horizontal line at point 'C'. From point 'C', drop a vertical line until it intersects with the skeleton curve at point 'D'. Point 'D' represents the yield point, and its corresponding horizontal coordinate is the yield displacement of the specimen.  
Generally, bent B2-PGS behaved worse than bent B2-CIP in terms of yield strength (612.88 kN vs. 683.27 kN), peak strength (698.84 kN vs. 810.30 kN), and ultimate lateral displacement (67.85 mm vs. 68.37 mm). Comparatively, the proposed GSS-GCT connection effectively enhanced both strength and ductility. Specifically, compared with the bent B2-CIP, bent B2-PGT increased the yield strength, peak strength, and ultimate lateral drift by 4.2%, 5.4%, and 22.3%, respectively. It is noteworthy that if the displacement ductility factor (\(\
u=\delta_{u}/\delta_{y}\)) is compared, bent B2-PGT performed worse than bent B2-CIP due to its relatively more significant yield displacement.