Experimental-numerical investigation and design of bolted-cover plate connections under bending for modular steel buildings

• Published in: Journal of Building Engineering Vol. 75; p. 107057
• Main Authors: Zhai, Si-Yuan, Lyu, Yi-Fan, Cao, Ke, Li, Guo-Qiang, Wang, Wei-Yong, Chen, Chen
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.09.2023
• Subjects: Bending behavior; Design model; Full-scale tests; Inter-module connection; Numerical simulation; Design model; Numerical simulation; Full-scale tests; Bending behavior; Inter-module connection
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2023.107057

The module-to-module bolted connection is an effective way of meeting the need for rapid assembly of modular buildings. This paper presents a discussion of five full-scale tests conducted on bolted cover-plate connections, investigating the effects of different strengthening methods, bolt-hole types, and boundary conditions on the bending behavior of such connections. An elaborate finite element model (FEM) was established and validated by the experimental results. Then, numerical simulations of key parameters were performed for comparative analysis. According to the force characteristics, the moment-rotation design model was proposed to describe the connection’s semi-rigid characteristic. The results show that the fracture of the beam flange is the load-bearing controlled damage mode of the connection. The load-bearing capacity of the connection is improved by both diagonal brace and flange strengthening designs without reducing the ductility. Compared with the circular bolt hole, the dual-slot hole hardly affects the connection force. Moreover, it reduces installation errors when assembling multiple modules. Furthermore, the beam with torsional instability has a reduction factor of 1.3 for both the initial rotational stiffness and yield moment. Finally, the mechanical model and design suggestions were given and validated based on the experimental and FEM results, which can accurately predict the moment-rotation relationship of this type of connection. •The bending behavior of the bolted-cover plate connection was investigated.•The method of improving the force and splicing efficiency of inter-module connection was given.•The effect of beam end torsion was obtained.•The experimental validated FEM was created and parameter analysis was conducted.•Design considerations were recommended using the mechanical model.