Advancing Modular Steel Structures: An Innovative Paradigm in Corner Connections for Enhanced Stability and Efficiency

This research addresses the structural challenges inherent in modular steel connections, exploring innovative approaches beyond traditional methods. Pre-fabricated modular steel structure connections normally incorporate a combination of welding, bolts, plates, and innovative methods, including post-tensioning and corner box inter-locking techniques. These connections are usually tested in a cantilever beam setup to assess their strength and structural behavior. As the load increases, the connection's resistance decreases, materials weaken, and deflection grows steadily until structural failure occurs. This often results in a low slip resistance within the connection corner, highlighting the need for upgrading and enhancing corner connections in pre-fabricated modular steel structures. Previous studies have mainly focused on variations of traditional techniques, such as different bolt setups and plate thicknesses for square sections of hollow steel members. This research proposes and analyzes a novel corner fitting connection applicable for connecting four modular units, forming an inter-sliding box design. The proposed connection, secured by bolts, significantly reduces construction time, eliminates the need for expert labor, and minimizes human error. The static finite element analysis demonstrates that the performance of the proposed inter-modular connection consistently falls within the rigid of both Eurocode and UK standards for service load, transitioning to semi-rigid towards the ultimate. Additionally, substantial improvements in displacement along the X, Y, and Z directions at the connection point and an increase in the initial rotation from 18.3 KN.m to 85 KN.m highlight the effectiveness of the proposed technique in enhancing pre-fabricated modular steel connections.