The rotational capacity of beams made of high-strength steel

Within the scope of the research project RUOSTE, the material characteristics and rotational capacity of beams made of high-strength steel grades S700 and S960 were investigated. In two test series, the achievements of cross-section class 1 and 2 were investigated. Beams made from high-strength steel are expected to have lower rotational capacity and are thus excluded from plastic/plastic design according to Eurocode 3 (EC3-1-1 and EC3-1-12). For specimens aiming at cross-section class 1, focus was on the material property requirements given in EC3-1-12. Although the material properties of high-strength steel supply lower strain hardening in the coupon tests than mild steels, combined with the actual ductility in the structural member, it might still be sufficient to reach the respective cross-section classification. A numerical model was calibrated based on the experiments and used for parametric studies, evaluating artificial stress–strain material curves, which were orientated at the lower limits given in the steel specifications.