PSI - Issue 58

Yazmin Sahol Hamid et al. / Procedia Structural Integrity 58 (2024) 130–136 Yazmin Sahol Hamid et al. / Structural Integrity Procedia 00 (2019) 000–000

134

5

column. Due to bearing forces, the PFC around the upper bolt hole was most affected. Fig. 4b shows X-axis rotation. The bottom flange of the PFC beam touched the diaphragm's lower side to resist Z-axis rotation. Load versus Displacement Curve Fig. 5a shows the WFBW and BW load-vertical displacement curves. The WFBW connection curve shows elastic deformation followed by plastic deformation to a 200 mm Y-direction displacement at the beam end. High flexural resistance causes the WFBW connection to gradually increase vertical load during initial loading. However, the BW curve shows that this connection can only withstand 67.6 mm displacement with a 7.03 kN vertical load. WFBW connection maximum load was 87.31 kN at 198.2 mm beam end displacement due to bearing failure around the top bolt hole and PFC beam top flange tensile deformation. Moment versus Chord Rotation Curve Fig. 5b shows the WFBW and BW moment-rotation curves. The WFBW curve maximum moment was 75.5 kNm at 0.23 rad. The WFBW connection's elastic and plastic behaviours are shown by the curve's early linear and nonlinear sections. The curves show that the WFBW connection has higher moment resistance than the BW connection. The semi-rigid welded region in WFBW helps transfer moments to the column. The BW results are consistent with a fin plate specimen tested by (Yang and Tan, 2013), where bolts caused shear forces to inhibit fin plate rotation. 4.2. Staggered and Non-Staggered Bolt Patterns The staggered bolt pattern can withstand up to 4800N with less than 50mm displacement before failing due to material limitations, as shown in Fig. 6a. In the yielding graph, the non-staggered bolt configuration allows nearly 200mm of displacement and has superior displacement retention. Because the staggered bolt handles 45.87mm displacement, its behavior is evaluated between 45mm and 50mm. Load increment and displacement are highly correlated. In terms of load capacity, the non-staggered bolt pattern outperforms the staggered pattern, highlighting the importance of bolt arrangement on intra-module connections. The study's analysis emphasizes that end distance, edge distance, and bolt spacing all have a significant impact on failure modes in both bolt arrangements. Higher S, Mises stress values indicate increased load-bearing capacity, indicating that the non-staggered pattern excels in displacement tolerance.

a

b

Fig. 5. (a) Load-displacement curves of the Type 1 (WFBW) and Type 2 (BW) connections; (b) Moment-chord rotation curves of the Type 1 (WFBW) and Type 2 (BW) connections.

Various Steel Grade Strength Fig. 6b shows the accuracy of FEM predictions in replicating the elastic and nonlinear structural behavior of specimens using load-displacement curves. The models maintain uniform member sizes, bolt placement, interaction types, and constraints for both steel grades. S275 and S355 grades are used in both models for the diaphragm, fin plate, circular hollow section, and PFC, ensuring consistency. S275 steel has an axial load maximum of 15.449 kN