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Cold-formed steel (CFS) buckling-restrained steel plate shear wall (SPSW) is a highly efficient lateral force resisting structure, which integrates architectural and structural functions. CFS stiffeners significantly reduces the out-of-plane deformation and improves the strength of SPSW. To investigate the effect of different arrangements of CFS on the buckling restraint of SPSW regardless of the effect of the surrounding frame, a finite element (FE) model of CFS buckling-restrained SPSW was developed and validated against the test results. Upon validation, a series of FE models were generated for parametric analysis. Based on the FE elastic buckling analysis method, the economic stiffness ratio of CFS to the steel plate was presented. Using the steel bar buckling theory, a simplified analysis model of the equivalent brace model considering the buckling-restrained effect of CFS on the steel plate was proposed. The simplified analysis model can consider the influence of buckling constraints and spacing on the buckling stress of the steel plate. Moreover, it can accurately simulate the stiffness and bearing capacity of the SPSW structure. The results show that the proposed simplified analysis model is accurate and consistent. • The FE model validated against test results was employed in the parametric study. • The economic stiffness ratio of CFS to steel plate was presented. • An equivalent brace model considering the buckling-restrained effect of CFS on steel plate was proposed. [ABSTRACT FROM AUTHOR]

In this study, a two-side-connected steel plate shear wall (SPSW) reinforced by cold-formed steel (CFS) strips on free edges is proposed. This structure has several advantages, including the ability to avoid additional bending moments on the frame column, convenient layout, and lightweight structure with good assembly effects. To understand the mechanical performance of the novel structure, horizontal reciprocating tests were conducted on two specimens; one was a two-side-connected SPSW reinforced on free edges without a frame and the other with a concrete-filled steel tube frame. The results showed that the two-side-connected SPSW reinforced on free edges still possessed good bearing and energy dissipation capacities. Finite element (FE) models were established, and the numerical analysis results were compared with the test results. Based on the verified FE model, a parametric analysis was performed, leading to the derivation of formulas for calculating the minimum stiffness ratio and buckling bearing capacity. Additionally, formulas for the yield bearing capacity and ultimate bearing capacity were derived based on the calculation formula for the buckling bearing capacity. To improve the design efficiency, a simplified truss model (STM) was proposed. The stress–strain relationship of the equivalent truss was established based on the aforementioned bearing capacity calculation formulas. The STM calculation results were compared with the test results, indicating a high level of accuracy and significantly improved calculation efficiency. • A two-side-connected steel plate shear wall reinforced on free edges is proposed. • The mechanical properties of the specimens were derived and analysed. • The calculation formulas for the elastic buckling, yield and ultimate bearing capacity were introduced. • To improve the design efficiency, a simplified truss model (STM) was proposed. [ABSTRACT FROM AUTHOR]

Concrete-filled steel tube-enhanced steel plate-reinforced concrete (CFST-SPRC) shear walls have been proposed for use in super high-rise buildings. This paper presents an experimental study of CFST-SPRC shear walls that aims to evaluate their seismic behavior. Three CFST-SPRC shear wall specimens with varying steel plate thicknesses and concrete strengths were tested under constant axial force and reversed cyclic loading. All of the specimens experienced a progression of failure from web concrete cracking, to local buckling of the steel tube plates, to fracturing of the vertical welds at the corners. One specimen exhibited brittle failure at the end of testing due to the sudden crushing of web concrete. Stable and full hysteretic behavior was developed by the shear wall specimens, indicating a capability for stable energy dissipation. The ultimate drift ratios were around 1.7% for all of the specimens. The flexural and shear deformations of the shear walls, and the base rotation caused by local deformations in the foundation beam, all provided a negligible contribution to the total lateral displacement. The proportions of the flexural displacement, shear displacement and rotational displacement to the total displacement were around 0.6, 0.2 and 0.2, respectively, for all specimens throughout the loading process. Simplified design methods were proposed for evaluating the load-carrying capacities of CFST-SPRC shear walls. The proposed method provided reasonable but conservative estimations for the test shear wall specimens. [ABSTRACT FROM AUTHOR]

Both concrete-filled steel tube (CFST) column and buckling-restrained steel plate shear wall (BRSPSW) have the advantages of high load-carrying capacity and superior seismic performance. The structural system composed of CFST columns and BRSBSWs will have the superior mechanical performance and be more suitable for high-rise buildings. In this study, the pseudo-static tests were carried out on the specimens of unstiffened steel plate shear wall and cold-formed steel (CFS) BRSPSW which were infilled in the single-span two-story 1/3 scaled composite frame respectively. The test results show that the CFS stiffeners have the obvious effect of restraining the outward buckling deformation on the steel plate, improving the lateral stiffness and resistance of the steel plate, and reducing the deflection deformation of the steel plate to the surrounding composite frame. The finite element (FE) model was established and validated, and the interaction between the BRSPSW and the composite frame was analysed. In combination with the theory and the FE analysis results, the maximum deflection limits of CFST column and steel beam were proposed to ensure the strength of the infill BRSPSW to give full play. Considering the separation of the steel tube wall of square CFST from the core concrete in the process of loading, the deflection limit of square CFST is proposed considering the separation effect of the steel tube wall of square CFST from core concrete under the action of infilled steel plate. • A novel buckling-restrained SPSWs with composite structure was investigated. • The interaction behaviour of buckling-restrained SPSW and boundary composite frame were discussed. • The deflection limit of square CFST and steel beams is proposed under the action of infilled steel plate. [ABSTRACT FROM AUTHOR]

In this paper, a simplified seismic design method of high-rise frame-steel plate shear wall (SPSW) system was proposed based on the multi-modal-analysis under the framework of performance-based seismic design. The seismic response of high-rise SPSW system was simplified to first and multiple-modal equivalent single degree-of-freedom (SDOF) oscillators. The dual frame-SPSW structure was decomposed into a frame system and SPSW system by controlling the relative contribution of SPSW system, and they were correspondingly simplified to a series of F-SDOF oscillators and S-SDOF oscillators. The analytical models of F-SDOF and S-SDOF oscillators were developed using the modal pushover analysis. By assuming the system responding linearly elastic for higher modes, the equivalent SDOF oscillator (D-SDOF) for the frame-SPSW system was developed by combining the F-SDOF and S-SDOF oscillators in parallel for each mode of vibration. The design procedure was developed based on the comparison of displacement thresholds against the displacement demands derived using the SRSS combination. A 15-story frame-SPSW system was adopted to verify the feasibility and demonstrate the design process of the simplified method. The result also shows the seismic demands derived by the equivalent dual SDOF oscillators have good consistency with that by frame-SPSW structure. Unlabelled Image • The multiple-modal equivalent SDOF oscillators were developed for the frame system and SPSW system. • A simplified multi-modal-analysis-based seismic design approach for high-rise frame-SPSW systems was proposed. • Demonstration of a case structure was provided and the efficiency was greatly improved. [ABSTRACT FROM AUTHOR]

Steel plate shear wall (SPSW) buckling-restrained by hat-section cold-formed steel is a new type of lateral bearing system that uses hat-section cold-formed steel members to restrain the buckling deformation of the SPSW. Integration of architectural and structural functions is achieved in this new shear wall system by externally bonding oriented strand board (OSB) and filling sound insulation material. A finite element (FE) model was developed and validated against seven experimental results in terms of failure modes, shear force-story drift angle curves and shear bearing capacities. Upon validation, an extensive parametric study was carried out to investigate the six key parameters including spacing of connecting bolts, geometries of hat-section steel, spacing of hat-section steel, steel material strength, width-height ratio of the SPSW and height-thickness ratio of the SPSW. Based on the 104 numerical results, new design rules are proposed to predict the stiffness, shear yielding strength and shear ultimate strength of this new type of buckling-restrained SPSW structure. By comparing the predicted results with experimental and numerical results, the proposed design method is found to be accurate and consistent. In addition, an equivalent cross-bar model is developed as a simplified substituted SPSW model to be used in theoretical modelling programmes in the future. • The FE model validated against test results was employed in the parametric study. • An equivalent cross-bar model is developed as a simplified substituted SPSW model. • The design rules for SPSW buckling-restrained by hat-section cold-formed steel were proposed. [ABSTRACT FROM AUTHOR]