On the behavior of an innovative four-layer semi-supported steel plate shear wall

Observations of past earthquakes as well as numerical and experimental studies have confirmed the acceptable performance of Steel Plate Shear Walls (SPSW). Although the SPSW has a number of advantages, it has two major flaws: low elastic-buckling capacity of the infill plate and significant stresses generated by the infill plate on the boundary columns. There are some techniques to overcome these shortcomings. Among them, using the semi-supported SPSW is the most effective one. However, the weak point of this system is the reduction of stiffness and strength of the system in comparison with the conventional SPSW. To resolve this issue, an innovative four-layer semi-supported SPSW has been introduced recently. The system is composed up of the main frame, secondary columns, two corrugated infill plates, and two flat infill plates. Since there is no connection between the infill plates and the mainframe, there is no stress transmission from plates to columns. This fact, in turn, reduces the ductility demand. As a result of the combination of the corrugated and flat plates, the buckling capacity of the wall increases nearly up to the yielding point. This results in a more cost-effective system. The current study presents the results of a comprehensive numerical study to investigate the effect of plate thickness, wall length, and aspect ratio on the behavior of this system under the monotonic lateral load. To obtain the pushover curves, the finite element (FE) software package ABAQUS was utilized. The findings showed that, as the aspect ratio of the wall increases, the wall capacity increases and exceeds the capacity of the frame. Furthermore, the relevant equations for achieving the pushover curve were proposed without the need for FE simulation. Finally, the results showed a good match between the FE results and the intended relations.