Seismic design and behavior of low yield point steel plate shear walls

Steel plate shear walls (SPSWs) with low yield point (LYP) steel infill plates have been demonstrated in a number of studies to be efficient and promising lateral force-resisting and energy dissipating systems. In fact, use of LYP steel with extremely low yield stress and high elongation capacity compared to the conventional steel enables the employment of infill plates with improved buckling stability, serviceability, and damping characteristics. In contrast to the commonly-used slender and conventional steel plates with relatively low buckling and high yielding capacities, LYP steel plates can have low yielding and high buckling capacities due to the early yielding of the steel material. On this basis, this paper aims at evaluating the structural behavior and performance of SPSWs with unstiffened LYP steel infill plates designed per AISC 341 seismic provisions which typically address SPSWs with slender infill plates. Effects of plate aspect ratio, and combined compressive and shear forces acting on the web plate are also considered in this study. Numerical analysis of the code-designed LYP steel shear wall models demonstrates the efficient strength, stiffness, and cyclic performances of such systems. In addition, the effectiveness of some design requirements specified in AISC 341 code is evaluated based on the behavior of the SPSW components, and design recommendations are provided accordingly. Finally, a modified plate-frame interaction (PFI) method is used to predict and characterize the behavior of SPSW systems with low yielding and relatively high buckling capacities, the effectiveness of which is verified by comparing the predicted response with experimental and numerical results.