Buckling of welded box columns made of high‐strength steels

Abstract Welded box columns made of high‐strength steels are characterized by high buckling resistance and low dead weight. The residual stresses introduced by the welding process are of particular importance. In the area of the weld seams, the cooling process creates residual tensile stresses that are in equilibrium with the compression stresses distributed over the cross‐section of the column. In Europe, the buckling resistance of box columns with welded cross‐sections made of high‐strength steels is insufficiently covered by the rules of EN 1993‐1‐1 and EN 1993‐1‐12. The application for columns made of high‐strength steels in the medium slenderness range is quite conservative. As part of the AiF‐FOSTA research project P1588, residual stress distributions of welded box sections were determined for steel grades S460 to S960. The buckling resistance was investigated experimentally and by structural‐mechanical calculations. The results lead to a re‐evaluation of the buckling curve assignment of compression members with welded box sections and to standardized residual stress distributions.