Numerical modelling and equivalent brace model of cold-formed steel buckling-restrained steel plate shear walls.

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]