Seismic demand assessment of self-centering steel plate shear walls

Abstract

In previous studies, a post-tensioned rocking system has been introduced to steel plate shear wall (SPSW) system as a means for reducing its residual drifts. The success of this method and the performance of self-centering SPSWs (SC-SPSWs) is evaluated, in this study, by nonlinear dynamic analysis of previously-designed structures. For this purpose, a numerical model is developed and validated against experimental results. This model is, then, used for representing five 3- and 9-story SC-SPSWs that reflect various design assumptions. The median and dispersion of various response parameters are then extracted using a set of 20 ground motion records scaled to three different intensity levels. A comparative assessment is next performed between response of the studied structures in presence and absence of the rocking system. This assessment reveals that the rocking system is not effective in reducing the residual deformations of SPSW system. Nevertheless, the rocking behavior is shown to effectively mitigate the ductility demand at the beams' end portion and provide a more uniform distribution of plasticity along beams and within web plates of different stories.