Cold-formed high-strength steel rectangular and square hollow sections under combined compression and bending

Abstract

High-strength steel is gaining more attention from engineers due to its high strength-to-weight ratio and cost effectiveness. However, the research on cold-formed high-strength steel (CFHSS) tubular members subjected to combined compression and bending is limited. This paper, therefore, presents an experimental investigation on this combined loading scenario, in particular at the cross-section level. The test specimens consisted of five square hollow section sizes and two rectangular hollow section sizes. The nominal proof stresses of the test specimens were between 700 and 900 MPa. A total of 51 short beam-columns were tested to investigate the behavior of CFHSS rectangular and square hollow sections subjected to combined compression and bending. A set of different initial loading eccentricities were adopted to attain a wide range of bending-to-compression ratios. The compression and bending capacities, load-deformation histories, and failure modes of the test specimens were reported. Based on the test results, the design methods described in American, Australian, and European codes were evaluated. Finite-element modeling methodology for CFHSS tubular beam-columns is also presented.