# 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
Considering bending and drilling difficulty of steel plate, the thickness parameter range was set by 2 mm interval from 6 mm to 14 mm. Two additional models with the inbuild component height of 650 mm and 700 mm are selected on the basis of 600 mm of the reference model. The moment-rotation curves with different inbuild component height were shown in Figure 17a; the initial stiffness amplitude of H600, H650 and H700 models was within 0.58%, and the ultimate bending capacity was 275 kNm, indicating that the height of the internal plug-in has little effect on the global mechanical behavior of the modular connection. Figure 17b showed the influence of the inbuild component thickness on the moment-rotation curves. There was little difference between each curve in the elastic stage, but obvious separation occurs in the elastic-plastic stage. Compared to the reference model P10, the initial stiffness of the P6 model and the P8 model decreased by 7.1% and 5.9%, respectively, while that of the P12 model and the P14 model increased by 5.4% and 5.7%. One can conclude that the initial stiffness of joints can be improved by increasing the thickness of the inbuild component. The ultimate moment of P6 to P12 models was between 274 kNm and 275 kNm, indicating that the thickness change of the inbuild component has little effect on the ultimate bearing capacity of connections. The moment-dislocation curves of different inbuild component heights and thicknesses were shown in Figure 18. For H600 to H700, the curves almost coincide with each other, which indicates that the height change has little influence on the relative dislocation between the upper and lower columns. For the P6 to P14 models, curves of the P10 to P14 models were significantly higher than that of the P6 and P8 models. When the bending moment reached 225 kNm, the curves of the P6 and P8 models showed an obvious elastic-plastic stage, and the relative displacement of the side column increases rapidly. However, the curves of the P10, P12 and P14 models have no obvious elastic-plastic stage. When the bending moment reached the maximum value, the dislocation of P6 and P8 was around 2.5 mm, which was 40% higher than that of reference model P10 (1.5 mm). The dislocation of P12 and P14 was 1.0 mm and 1.4 mm, respectively, which is 33.0% and 6% lower than that of reference model P10. Hence, the dislocation between upper and lower columns can be reduced by increasing the thickness of inbuild component. The rotation difference moment curves with different inbuild component heights are shown in Figure 19a, indicating that the variation of inbuild component heights has little effect on the connection continuity index. Figure 19b showed the rotation difference-bending moment curves of different inbuild component thicknesses. At the initial stage (bending moment less than 100 kNm), the difference between curves was not obvious. When the bending moment reached 150 kNm, the curve began to separate, and the higher the thickness of the inner plug is, the better the continuity of the node. When the bending  
Figure 12:0 Moment-rotation curves: (**a**) The height of inbuild component; (**b**) The thickness of inbuild component. moment reached 250 kNm, the curves of the P6 and P8 models began to rise sharply and diverge, while the values of the P10 to P14 models remained at a low level. The above analysis showed that the inbuild component thickness had greater influence on the connection mechanical properties than the height. The Mises stress distribution of inbuild component in models P6 to P14 was shown in Figure 12:1 The stress concentration area was mainly distributed at the junction of the upper and lower columns. The inbuild component wall of model P6 and model P8 revealed obvious depression in the stress concentration area, which could not continue to constrain the relative dislocation of upper and lower columns to improve the continuity of joints. The yield area of P12 and P14 was significantly smaller than that of the P6 and P8 models.