Experimental and Analytical Study of Eccentrically Braced Frames Combined with High-Strength Steel

Abstract

In the structure of high-strength steel composite eccentrically braced steel frames (HSS–EBFs), the links and braces are made of Q345 steel, while the non-energy-dissipation segments (columns and beams) are made of high-strength steel (HSS). HSS reduces the cross-section of the members and increases the economic efficiency. Here, four groups of K-HSS–EBFs are designed by performance-based plastic design method in this paper, which includes 5-storey, 10-storey, 15-storey and 20-storey, and each group contain four different link length (900, 1000, 1100 and 1200 mm). The cyclic test loading was applied to 1:2 scale three-storey K-type HSS–EBFs (K-HSS–EBFs) with shear links to investigate their seismic performance. The results indicate that the as-prepared K-HSS–EBF structure exhibits excellent bearing capacity, ductility, and energy dissipation. We also find that the fracture of the link web in the second storey led to the degradation of the load-carrying capacity. The non-designated yield members remained in the elastic stage, whereas the links ultimately experience inelastic rotations, and thus dissipate the energy in the K-HSS–EBFs. Moreover, nonlinear pushover analyses and nonlinear dynamic analyses are conducted, and the loading capacity, link rotations, ductility, interstory drifts and failure mode under rare earthquake of all models are compared. The results indicate that K-HSS–EBFs with different link length have similar deformation characteristic and failure mode under pushover analysis or rare earthquakes, and the interstory drifts, link rotations and ductility of HSS–EBFs are increased with rising the link length.