# A Component-Based Model for Novel Modular Connections with Inbuild Component
## 2 Parameter Analysis
### Parameter Analysis Results
#### 2.3.2 Thickness of Beam End Plate  
In order to understand the influence of beam end plates on mechanical properties of new modular building joints in a more comprehensive way, end plates with thickness of 6 mm to 16 mm (2 mm interval) were selected for parameter analysis based on the reference model. Among them, D6 and D8 were used to study the mechanical properties of joints with end-plate thickness less than or equal to column flange thickness, respectively. D12 to D16 were used to study the effect to modular connections when the thickness of end plate was greater than that of column flange. Figure 13 shows the influence of the thickness change of the end plate on the moment-rotation curve. The overall trend is that  
Figure 11: Stress distribution of side plates. Figure 12: Stress distribution of columns with different bolt preload. Figure 10: Continuity index-moment curves of connections: (a) Thickness of side plate; (b) Bolts preload. the connection with higher thickness of the high-end plate has better mechanical properties. For D6 and D8, the initial stiffness of connections was reduced by 11.0% and 6.7%, and the ultimate moment resistance capacity was reduced by 4.7% and 2.9%, respectively, as compared to the reference model. When the end plate thickness is increased (D14, D16), the initial stiffness was increased by 3% and 7.2%, and the ultimate moment resistance strength was increased by 1.1% and 2.2%, as compared to the reference model. The influence rule of end plate thickness on relative dislocation between upper and lower columns is shown in Figure 14. When the bending moment reached 225 kNm, the D6 and D8 models showed an obvious elastic-plastic stage, while the D12 to D16 models did not. When the maximum bending moment was reached, the horizontal displacement differences of D12, D14 and D16 were 1.54 mm, 1.39 mm and 1.24 mm, respectively, while those of D6 and D8 were 2.70 mm and 2.12 mm, respectively. After the connection reached the maximum bending moment, the curves of D12, D14 and D16 models showed a smooth descending section, while those of D6 and D8 models showed a slightly divergent state. Figure 14: Moment-relative dislocation curves of connections with different end plate thickness. Figure 13: Moment-rotation curves of connections with different end plate thickness. The continuity index curves of different end plate thicknesses were shown in Figure 15. It can be seen that the continuity index of D12, D14 and D16 models was significantly stronger than that of D6 and D8 models. Moreover, the curves of D12, D14 and D16 almost coincide, indicating that increasing the end plate thickness on the basis of the reference model have little impact on the continuity of connections. According to the above analysis, increasing the thickness of the beam end plate can improve the mechanical behavior and continuity of the connection. Mises stress distribution of D6, D12 and D16 models at the final loading stage was shown in Figure 16a, and the parts of stress over 345 MPa were indicated in gray. The yield area of the end plate with high thickness is small, which improves the ultimate bearing capacity of the joint. The stress distribution in the joint panel of D6 and D16 models at maximum moment is shown in Figure 16b. The end plate is connected with the column flange by welding. Increasing the thickness of the end plate is equivalent to improving the strength of the beam-column connection, and the initial stiffness of the global modular connection is improved by reducing the deformation of the column flange. At the same time, higher thickness of the end plate can better protect the inbuild component from local buckling under the ultimate load, thus improving the continuity of intermodule connection. Figure 16: Mises stress distribution of modular connections: (**a**) Beam end plate; (**b**) Joint panel. Figure 15: Continuity index-moment curves of connections with different end plate thickness. 2.3.3. The Height and Thickness of the Inbuild Component  
The inbuild component is made by bending a steel plate.