Influence of the temperature‐dependent toughness on the structural resistance of high‐strength steels

Structural steels with high strengths enable slender and material saving, thus particularly sustainable construction. According to EN 1993‐1‐12, design of steel structures is already possible up to steel grade S700. After revision, now the design of steels up to S700 is regulated in FprEN1993‐1‐1. However, already now, the standardisation committee CEN/TC/250/SC3 has commissioned its respective WG12 to prepare rule proposals for the design of steel structures involving steel grades from S700 to S960. Clarification of the material requirements in this context is at the beginning of the works. The question arises whether the set of requirements as formulated so far for steels up to S700 can continue to exist not only in the amount of minimum or limit values but also whether the type of requirements would then still be appropriate. This article reports on component‐scale experimental investigations on several high‐strength steels S700–S960 (HSS) with special focus on the dependence of the load‐bearing behaviour and the ductility properties on the varying material toughness at different temperatures. For lower shelf, the results can be compared with the current design approach to avoid brittle failure according to EN 1993‐1‐10, while experimental investigations also allow for evaluating the upper‐shelf toughness behaviour and to ensure ductile behaviour.