Experimental Study of Diagonally Stiffened Steel Plate Shear Walls

Upon recent research, steel plate shear wall (SPSW) is known as an effective lateral force resisting system in high seismic zones. However, there are still areas of concern in the design and construction of this system with regard to conventional approaches recognized as stiffened and unstiffened types. This paper presents results of research conducted on diagonally stiffened steel plate shear walls as a new type of stiffening method. Four 1/2-scaled single-story test specimens are designed as prototype thin steel plate shear walls for the experimental study. Three of the specimens are diagonally stiffened, and the fourth one is an unstiffened steel shear wall. Testing of the systems is performed under cyclic quasi-static loading. The effects of the edge stiffeners and the type of beam-to-column connections on the seismic behavior of the diagonally stiffened specimens are also investigated. Experimental results show that the specimens tolerate 3.5% to approximately 5% story drifts, and the diagonal stiffeners improve hysteretic behavior of the steel shear walls, especially when the edge stiffeners are used in the panel. The results indicate that the response modification factor (R) of a diagonally stiffened specimen is approximately 13% greater than the R factor of an unstiffened system. In addition, a formula is developed and proposed for the shear strength estimation of a diagonally stiffened SPSW. The theoretical predictions of the shear strengths are compared with the experimental results, and good agreements are observed between the two methods.