The design standard “Eurocode 3: Design of steel structures – Part 1-9: Fatigue” provides rules to determine the fatigue resistance for details of steel structures. The S-N curves provided in the standard are for welded or bolted connection details as applied in “traditional” structures with steel thicknesses in accordance.
Cold-formed members and connections subjected to fatigue are generally bolted, the relatively small thicknesses (1 mm – 6 mm) prevent 3-dimensional stress distributions. Therefore, the design rules in EN 1993-1-9 need to be improved for cold-formed structural details.
The objective of FASTCOLD is to study, in relation to fatigue of components and joint-details, the influence of:
- virgin material (continuous hot dip zinc coated or “black” steel, steel grade);
- forming process (roll forming or press brake affecting residual stresses, ratio radius/thickness)
- manufacture of continuous holes (by punching or drilling) and
- type of loading, to obtain design procedures and parameters suitable for cold-formed structural steel details.