مطالعه عددي و تجربي ديوار برشي ورق فولادي كمانش¬تاب توسط شبكه سخت شده فولادي با آرايش¬هاي مختلف

Experimental an‎d numerical study of buckling-restrained steel plate shear walls (BR-SPSW) with multiple steel stiffeners in different arrangements

مهندسي عمران

To enhance the seismic performance of lateral load-resisting steel systems an‎d improve the post-buckling behavior of steel plate shear walls, the role an‎d configuration of stiffeners as an effective strengthening strategy have been investigated. In this study, the seismic behavior of buckling-restrained steel plate shear walls is eva‎luated with a focus on the influence of stiffeners using a combined numerical–experimental approach. In the numerical part, finite element modeling of buckling-restrained steel plate shear walls was conducted using ABAQUS. The nonlinear behavior, mechanical properties of steel, an‎d failure criteria were incorporated into the models. Nonlinear analyses including buckling mode analysis, pushover analysis, an‎d hysteresis analysis were performed under cyclic seismic loading with appropriate boundary conditions. Mesh generation an‎d mesh sensitivity studies were also carried out. Model validation was performed based on reliable references an‎d experimental data. Seismic performance indices such as energy dissipation capacity, initial stiffness, ductility factor, displacement at 4% drift, an‎d the ratio of internal to kinetic energy were eva‎luated. Finally, the numerical models were categorized into six groups: unstiffened walls (baseline models), walls with strip stiffeners, rebar stiffeners, angle stiffeners, box-section steel stiffeners, an‎d walls with discontinuous connections. In the experimental section, a one-quarter scale buckling-restrained steel plate shear wall specimen with three horizontally arranged box-section stiffeners was fabricated an‎d tested under cyclic loading to obtain its seismic response. Subsequently, the corresponding numerical model was developed in ABAQUS considering material properties obtained from experiments, boundary conditions, loading history, failure models, an‎d appropriate meshing, enabling a reliable comparison between numerical an‎d experimental results. Comparison between numerical an‎d experimental results demonstrated very good agreement, with nearly overlapping hysteresis curves. The differences in initial stiffness an‎d ductility factor were 1.7% an‎d 2.7%, respectively, while energy dissipation capacity was also accurately predicted by the numerical model. Parametric studies indicated that the use of stiffeners generally enhances the ultimate load capacity, initial stiffness, an‎d energy dissipation capacity of buckling-restrained steel plate shear walls. Increasing plate thickness in unstiffened models led to higher load-carrying capacity an‎d initial stiffness, but reduced ductility. In stiffened configurations, diagonal stiffener arrangements generally increased initial stiffness an‎d, in some cases, ductility, whereas horizontal an‎d vertical arrangements were more effective in improving energy dissipation. In the rebar-stiffened group, using fewer bars with larger diameters enhanced energy dissipation, an‎d the behavior was highly dependent on rebar configuration. Moreover, in walls with discontinuous connections, the baseline model exhibited the highest stiffness an‎d load capacity, while the combination of vertical discontinuous connections with vertical stiffeners provided the highest ductility.

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