Experimental and numerical investigation of coupled steel plate shear wall with slits

This study investigates the seismic performance of coupled steel plate shear walls with slits (C-SPSWS), a novel lateral load-resisting system that integrates the benefits of coupling beams and slit steel panels. A four-story, 1:3-scale experimental model was subjected to cyclic loading to evaluate its hysteretic behavior, failure modes, and energy dissipation. Numerical models, validated with experimental data, were used to analyze the effects of coupling beam dimensions and lengths on the system performance. The experimental results indicate that primary damage occurs in the slit wall panels and coupling beams, while boundary frame elements remain largely intact. Premature weld cracking in the coupling beams was identified as a major factor reducing the load-carrying capacity and energy dissipation, highlighting the importance of reliable beam connections. The system exhibited stable hysteretic behavior, excellent energy dissipation, and a ductility ratio of 5.16, demonstrating robust seismic performance. Parametric studies reveal that increasing coupling beam cross-sectional dimensions enhances shear strength and energy dissipation but reduces ductility and material efficiency if excessively large. Additionally, shorter coupling beams improve energy dissipation and ductility, while longer beams increase stiffness but compromise material efficiency. An optimal degree of coupling range of 0.4–0.6, with coupling beams designed to remain in the shear-yielding range, is recommended for achieving a balance between strength, ductility, and material efficiency. These findings provide practical guidance for the design and application of C-SPSWS in seismic-resistant buildings.