Flange effects on the behavior of double-plate composite shear walls with steel fiber concrete constrained by stud and bolt connections

This study explores the seismic performance of double-plate steel fiber reinforced concrete shear walls (DSRCWs), primarily focusing on the influence of flange geometry. Five half-scale specimens, including I-shaped and T-shaped configurations with varying flange widths, were tested under axial and cyclic lateral loading. The experimental results revealed that the presence and width of the flange significantly enhance the load-bearing capacity, stiffness, and overall seismic performance of the walls. Introducing a 600 mm flange increased bearing capacity by up to 52 % compared to non-flanged walls, and a moderate reduction in deformation capacity. Further increasing the flange width to 900 mm yielded only marginal gains, indicating the existence of an effective flange width threshold. T-shaped walls outperformed I-shaped walls in strength, ductility, and energy dissipation. Additionally, steel fiber inclusion improved structural resilience, and stud connections provided better ductility than bolts. A simplified model for estimating the lateral capacity of T-shaped DSRCWs demonstrated a strong correlation with experimental results. These findings underscore the critical role of flange design in optimizing the seismic performance of composite shear wall systems for high-rise construction.