Enhancing Lateral Behaviors of Steel-Framed Modular Structures Taking Advantage of Steel Plate Shear Walls

Abstract

Steel-framed modular structures, assembled by stacking modules, show distinct lateral behavior. However, the role of steel plate shear walls (SPSWs) in such structures is rarely studied. This study investigates their influence on the lateral behavior of steel-framed modular structures. Two six-story modular structures are designed: one without SPSWs while the other one with SPSWs. The base shear, failure process, and resisting mechanism of modular structures are studied by pushover analyses. Parametric studies address effects of plate thickness, bolt number, and cross-section of horizontal inter-module links. Contributions of SPSWs and concrete shear walls are compared. For the first time, three distinct resisting mechanisms—individual resisting unit, double-column system, and double-beam system—are identified and systematically explained in the context of SPSWs-enhanced modular structures. A novel tension-tie strip model is developed to quantify the contribution of SPSWs to lateral resistance. Results demonstrate that SPSWs work as tension-tie strips, significantly increasing the stiffness and resisting capacity of modular structures by three to five times depending on the loading direction. The resisting capacity grows with plate thickness. Insufficient bolts or link cross-section can lead to premature failure. Compared to concrete shear walls, SPSWs offer better integrity and drift control under extreme seismic loads. A design scheme is proposed to estimate the increased resistance due to SPSWs with good accuracy and efficiency, offering a practical tool for structural engineers to enhance lateral behavior. The findings provide new insights into the seismic design of modular buildings and establish a foundation for performance-based design of SPSW-reinforced modular structures.