Steel plate shear walls for seismic design and retrofit of building structures
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Steel plate shear walls (SPSWs) are investigated in this dissertation, for use in retrofit and new design as a lateral force resisting system in building structures. Limits for sizing (for moment strength) of anchor beams, at the upper and lowermost levels of a multi-story SPSW frame, are introduced and developed. Approximate limits for frame drift at yield are developed for both a bare frame, and including an SPSW, with the intention of designing the infill panel as a "fuse" to yield and dissipate seismic input energy while protecting the surrounding framing. An experimental program of single-story, single-bay SPSW frames is outlined and some results are presented. The tested specimens utilized low yield strength (LYS) steel infill panels and reduced beam sections (RBS) at the beam-ends. Two specimens make allowances for penetration of the panel by utilities, which would exist in a retrofit situation. The first, consisting of multiple holes, or perforations, in the steel panel, also has the characteristic of further reducing the corresponding solid panel strength (as compared with the use of traditional steel). The second such specimen utilizes quarter-circle cutouts in the panel corners, which are reinforced to transfer the panel forces to the adjacent framing. All specimens resisted quasi-static loading from an imposed input history of increasing displacements to a minimum drift of 3%. The perforated panel reduced elastic stiffness and overall strength of the specimen by 15% and 19%, respectively, as compared with the solid panel specimen. Analytical models utilizing the Finite Element Method (FEM) are developed to represent the specimens in the experimental program, with good agreement observed between the analytical models and experimental results. Variations of the perforated wall model are analyzed and compared with FEM of simple perforated tension strips to quantify limit states of this system, using material elongation around perforations as the criterion. Recommendations are made for the ductile design of these systems. Column twisting near the RBS connections during testing is investigated and compared with research on this topic in frame tests without SPSWs. Design recommendations are made for the use of RBS connections in SPSW anchor beams.