Local Buckling of Welded Box Beams Made of Ultrahigh-Strength Steels

Laboratory tests have shown that current standardized design rules lead to overly optimistic results for calculated ultimate loads of plated structures, especially for internal elements such as box beams. Additionally, the validity of applying equations to compute local buckling resistance might be restricted to steel grades for which the yield strength is less than 500-700MPa. Both the literature survey and recent experimental buckling tests using ultrahigh-strength steel (UHSS) show that the current design equations can be extended to at least a nominal yield strength of 1,000MPa. Additionally, a new simplified equation for the reduction factor is proposed and a statistical calculation is presented to compare current and proposed calculation methods.