# A Study on the Seismic Performance of Steel H-Column and T-Beam-Bolted Joints
## 4 Parametric Analysis
### Parameter Analysis of T-Part 2  
In this section, a comparison was made regarding the changes in the web thickness and flange thickness of T-part 2. A total of 10 groups of variables were set up. Specifically, five groups were designed to explore the influence of the web thickness of T-part 2 being 6 mm, 8 mm, 10 mm, 12 mm, and 14 mm on the nodes, with BT2F denoting the variation in the web thickness of T-part 2. In the other five groups, variable parameters were assigned to the flange thickness of T-shaped parts, with values of 8 mm, 10 mm, 12 mm, 14 mm, and 16 mm, respectively. BT2Y represents the change in the flange thickness of T-parts 2. The model parameters are presented in Table 6.  
The stress of the joint and T-part 2 under different web thicknesses of T-part 2 is presented in Figure 15. From Figure 15, it is obvious that when the web thickness is small, the interface area between the web of T-part 2 and the flange, as well as the bolt holes on the web, are the first areas to experience plastic deformation. As the web thickness of T-part 2 increases, the yield area in the tensile zone of the web of T-part 2 gradually diminishes. Moreover, the degree of deformation of the web of T-part 2 also weakens, and the corresponding stress level decreases. The increase in web thickness of T-part 2 has little effect on joint failure mode. The influence of web thickness on the development of joint stress and deformation is not obvious. The stress of the nodes and T-part 2 under different flange thicknesses of T-part 2 is depicted in Figure 16. When the flange thickness is small, the deformation in the flange-hole area of T-shaped part 2 is significant, and the stress from the flange bolt holes to the junction with the web is high. As the flange thickness of T-part 2 increases, the degree of deformation weakens. The clearance between the flange of T-part 2 and the web of the \begin{table}
\begin{tabular}{c c c c c c} \hline Model number & BT2F-1 & BASE & BT2F-3 & BT2F-4 & BT2F-5 \\ Web thickness (mm) & 6 & 8 & 10 & 12 & 14 \\ Model number & BT2Y-1 & BT2Y-2 & BASE & BT2Y-4 & BT2Y-5 \\ Flange thickness (mm) & 8 & 10 & 12 & 14 & 16 \\ \hline \end{tabular}
\end{table} 
Table 6: T-parts 2 node model parameters of different thicknesses. Figure 15: A total of 6 and 14 web thickness T-part 2 stress. (**a**) BT2Y-1. (**b**) BT2Y-5. H-shaped steel beam becomes smaller, the yield area of the flange gradually decreases, and the stress level also drops. Increasing the flange thickness of T-part 2 has no obvious impact on joint stress and deformation. Moreover, the change in flange thickness has little effect on the joint failure mode. Figures 17 and 18 present the comparison diagrams of the skeleton curves of nodes under different web and flange thicknesses of T-parts 2. The results indicate that as the web thickness of T-part 2 increases, the yield load and bearing capacity of the space nodes increase, yet the improvement degree is not significant. Specifically, the yield load and bearing capacity of the BT2F-5 nodes increase by less than 1% compared to those of the BASE nodes. The change in web thickness of T-part 2 has little effect on the slope of the skeleton curve (Figure 17), indicating that its contribution to the initial stiffness is limited. As the flange thickness of T-part 2 increases, the yield load and bearing capacity of the space nodes show no obvious changes, and the yield load and bearing capacity of the BT2Y-5 nodes are less than 1% higher than those of the BASE nodes. The web thickness of  
Figure 16: A total of 8 and 16 flange thickness T-part 2 stress. (**a**) BT2F-1. (**b**) BT2F-5. Figure 17: T-part 2 node skeleton curves under different web thicknesses. Figure 18: T-part 2 node skeleton curves under different flange thicknesses. T-part 2 has no obvious impact on the joint stiffness. The stiffness of the joint increases with the growth of the flange thickness of T-part 2. Specifically, the stiffness of the BT2Y-5 node is approximately 6% higher than that of the BT2Y-1 node.