Behavior of Steel Plate Shear Walls Subjected to Repeated Synthetic Ground Motions

Steel plate shear walls (SPSWs) have been shown capable of remaining stable under seismic loading due to their satisfactory hysteretic performance. However, since the thin steel web infills within these walls only yield under tension and in most cases exhibit no significant compressive resistance, their behavior is uncertain under long duration of shaking. The scope of this research was to investigate whether there is a point in time where the SPSW behavior becomes that of its own bare frame when subjected to extensive shaking, which would indicate that the steel web plates no longer contribute to response. In this parametric study, SPSWs of various configurations were analyzed using nonlinear inelastic dynamic analyses, for which response modification factor and duration of repetitive synthetic ground motions were varied. Two single-story SPSWs (with panel aspect ratios of 1: 1 and 2:1) and one 3-story SPSW (having panel aspect ratio of 1:1) were modeled using the commonly used diagonal strip model. Spectra-compatible synthetically generated ground motions were used in the analyses. SPSW responses were then compared against those of their respective boundary frames. Performance of SPSW over the duration of the repeated stochastic ground motions was characterized by inelastic and residual drifts. The objective of this research was to provide an understanding of the expected ductile performance of SPSWs when subjected to prolonged seismic excitation, and hopefully, an improved confidence in their seismic behavior under such conditions. (C) 2019 American Society of Civil Engineers.