Development of Ring-Shaped Steel Plate Shear Walls

Steel plate shear walls (SPSWs) are an attractive option for seismic lateral load resisting systems for both new and retrofit construction. However, the current approach to SPSWs in the U.S. typically uses very thin web plates, large boundary elements, and requires costly moment connections. Resulting SPSWs suffer from early buckling and subsequent tension-only plate behavior which leads to pinched hysteretic behavior, reduced stiffness, and limited energy dissipation. Moreover, the large boundary elements and moment connections can make SPSW less economical than concentrically braced frames. This paper describes a new type of SPSW referred to as ring-shaped steel plate shear walls (RS-SPSWs) which build on the advantages of steel plate shear walls, but have improved seismic performance, develop reduced demands on boundary elements, and allow simple shear beam-to-column connections. RS-SPSW reduces buckling by utilizing a unique pattern of ring-shaped cut-outs. The ring shape acts to remove excess material in the direction transverse to the tension direction thus reducing the amount of buckling. Its geometric features also result in more independent variables which can be varied to separately tune aspects of system behavior like strength, stiffness, ductility and energy absorption of the shear wall system. This paper focuses on the effect of geometric design variables on system behavior. After validation against experimental test results, finite element modeling is used to perform a parametric study.