End plate–stiffener connection for SHS column and RHS beam in steel-framed building modules

This paper investigates the mechanical performance of beam-to-column connections for steel-framed building modules with RHS and SHS sections of relatively small member sizes. In the experimental program, three forms of connections are tested under static bending, including a completely welded connection (W), a bolted end plate connection (EP) and the proposed end plate–stiffener connection (ST), and the failure modes, moment–rotation behaviours and strain responses were recorded during experiments. Results show that ST connection exhibited superior connection strength, stiffness and ductility compared with the EP connection. In addition, a detailed finite element analysis was conducted to model the connection behaviours, considering bolt pretension, contact behaviours and detailed bolt geometry, showing good comparison with experiments. Furthermore, a parametric study was performed on the end plate thickness and stiffener thickness for the proposed end plate–stiffener connection. Such results finally enable a comparative study to investigate the performance of module during road transportation, highlighting the effects of connection stiffness.