Experimental Study on Seismic Behavior of 460MPa High Strength Steel Box-Section Columns

Abstract

In order to study the seismic behavior of 460MPa high strength steel (HSS) box-section columns, five specimens with equal-width box-section were examined under constant axial load and cyclic horizontal load simultaneously. The axial load ratio and width-to-thickness ratio were designed as major parameters in this investigation. Failure mode, hysteretic curve, energy dissipation capacity and ductility were analyzed and compared. The experimental results showed that local buckling initiated at flange and followed by web. Under the same axial load ratio, as width-to-thickness ratio increased, local buckling occurred at a lower displacement level and the displacement levels at both peak load and failure load decreased. On the other hand, with the increase of width-to-thickness ratio, the range of local buckling wave became smaller, and the position of buckling center became closer to fixed end. It is also evidenced that the full extent of hysteric curve, energy dissipation capacity, ductility of specimens and ultimate story drift angle decreased with the increase of width-to-thickness ratio and axial-load ratio. According to the experimental results and comparative study, limiting values of width-to-thickness ratio for flange plate of Q460 box-section may be suggested as 25 for applications with large inelastic deformation (i.e. large earthquake action) and 32 for applications with limited inelastic deformation (i.e. moderate earthquake action) in the case that axial-load ratios are no more than 0.2.