Experimental and Numerical Study on Lateral-Torsional Buckling Behavior of High Performance Steel Beams

A new type of high performance steel (HPS), designated WGJ steel, with high strength as well as improved fire and corrosion resistance, was recently developed by Wuhan Iron and Steel (Group) Company. This paper investigated the lateral-torsional buckling behavior of beams fabricated of WGJ steel through experimental and numerical analysis. Welded I-section beams were tested under concentrated loads, which indicated that lateral-torsional buckling was the dominant failure mode. A finite element model was established and validated by the experimental results. Parametric analyses were conducted to further understand the effect of steel strength on the lateral-torsional buckling capacity of steel beams. The numerical results were compared with design values obtained from the clauses in Eurocode 3 and GB50017. It is found that the design equations in GB50017 give less safe margins for the overall stability design of welded I-section beams fabricated of WGJ high performance steel, whereas Eurocode 3 appears to be more conservative in all conditions.