The design rules for the verification of civil engineering steel structures against fatigue are compiled in the European harmonized design standard Eurocode EN 1993-1-9 released in 2005. Currently, this design standard is under revision. Besides the inclusion of new developments and clarification, this revision aims for an improvement of the user-friendliness and an extended degree of harmonization by reducing the number of the so-called nationally determined parameters. The structure of the revised standard has been modified in comparison to the current one in order to facilitate the application of the standard. In addition, the following major changes have been implemented:
- Improvement of S-N curves in terms of the nominal stress method: clarification of stress computation, re-organization of detail category tables.
- New design rules for the hot-spot-stress and the effective notch stress methods, in separate annexes.
- New annexes to determine the most common magnification and stress concentration factors for the modified nominal stress method and the stress ranges in preloaded bolts.
Meanwhile, the final document of the project of the European design standard Eurocode prEN 1993-1-9 has been submitted to the “CEN Enquiry”. Thereafter it will go through the Formal Vote, planned for October 2024, before replacing the 2005 version throughout Europe.