Vol.:(0123456789) 1 3 International Journal of Steel Structures https://doi.org/10.1007/s13296-019-00214-6 End Plate–Stifener Connection for SHS Column and RHS Beam in Steel‑Framed Building Modules Fu Jia Luo 1,2  · Chenting Ding 1  · Adam Styles 1,2  · Yu Bai 1 Received: 31 July 2017 / Accepted: 12 February 2019 © Korean Society of Steel Construction 2019 Abstract 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–stifener 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, stifness and ductility compared with the EP connection. In addition, a detailed fnite 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 stifener thickness for the proposed end plate–stifener connection. Such results fnally enable a comparative study to investigate the performance of module during road transportation, highlighting the efects of connection stifness. Keywords Modular construction · Steel module · Beam-to-column connection · Tubular member · Moment-rotation behaviour · Module transportation 1 Introduction Modular construction, which comprises of-site fabrica- tion (see Fig. 1a), transportation (see Fig. 1b) and on-site assembly (see Fig. 1c) of volumetric or panellised modular units, has signifcantly transformed the building and con- struction industry. It brings benefts such as both construc- tion time and cost saving, better quality control, reduced interruption by weather and reduced wastage, and therefore become attractive when there is a demand for economic manufacturing, construction speed, minimum disruption due to construction (Lawson et al. 2014). To date, modular construction has been used in various sectors of building industry, particularly educational, commercial, residential and health sectors (Lawson et al. 2014; MBI 2017). In the recent decade, there has been a growing interest in modular construction (Lacey et al. 2018; Murray-Parkes et al. 2017), particularly in North America, Europe, Australia and East Asia. Based on the building industry of North America, the market share of modular construction steadily expanded from 2.4% to 3.2% from 2014 to 2016 in (MBI 2017). A steel-framed volumetric module is a common type of modular units in which the steel framing provides a struc- tural framework for slab, cladding, plasterboard and other attaching fnishes. In addition to compliance of structural design standards as traditional buildings (Murray-Parkes et al. 2017), an added design consideration for a single mod- ule is to sustain the racking action during transportation and craning process (see an example of module transportation in Fig. 1b). This also tends to be the highest risk phases in the life of modular components (Garrison and Tweedie 2008), not only for structural members but also for non-structural components, such as plasterboard panels and their screw connections to structural cold-formed steel (Innella et al. 2018) where their deformations are largely constrained by the stifness of structural parts. To ensure adequate struc- tural stifness and stability, the use of bracings, interme- diate posts, wall studs (see Fig. 1d) and moment-resisting beam-to-column connections is encouraged for steel-framed Online ISSN 2093-6311 Print ISSN 1598-2351 * Yu Bai yu.bai@monash.edu 1 Department of Civil Engineering, Monash University, Clayton, VIC 3800, Australia 2 Present Address: Multiplex Engineering Innovations Group, Kew, VIC 3101, Australia