Bending behavior of detachable tapered-head bolt inter-module connection of steel modular structure

Abstract

The force transmission between steel module units is primarily achieved through inter-module unit connections. However, the existing connections often fail to meet the installation requirements for central connections, and some connections require on-site welding and are difficult to disassemble, with strict demands on the cross-section of beams and columns. To address the shortcomings of the current connections, a detachable tapered-head bolt inter-module connection of steel modular structure is proposed. It solves the problem of limited installation space for central connections, enabling rapid installation and disassembly with high construction efficiency. A study on the bending behavior of the connection under static load is conducted through four-point bending tests. Various mechanical characteristics, including failure mode, ductility, load-bearing capacity, and strain distribution are investigated. The results indicate that the primary failure mode for the connection under bending moment is the yielding of the bottom plate of the upper corner part, demonstrating a ductile failure mode. The results of parametric numerical simulations show that increasing the bottom plate thickness and side plate thickness of the upper corner part are effective measures to improve the connection bending performance. Furthermore, the simplified theoretical calculation model for the connection is established, and the formula for calculating the bending bearing capacity is proposed. This provide a reliable design basis and reference for the practical application of the connection in engineering projects.