A design approach for thin-walled, cold-formed steel sections using the example of bending load

As part of the FOSTA research project P1328 (IGF No. 19964 N), a design approach for thin-walled, cold-formed steel sections was developed. It transfers the cross-sectional load bearing capacity, which is determined following the American standard AISI 100-16-Direct Strength Method based on numerical elastic critical buckling analysis, into the European design concept of EN 1993-1-3 for global/coupled stability checks. To verify this design approach for thin-walled, cold-formed members under bending loads about the strong cross-sectional axis, experimental tests were performed on various C- and Omega-shaped sections. To extend the test matrix, an FE model was validated on the tests in order to subsequently prove the applicability of the new combined design approach by numerical parameter studies. This article is limited to the general explanation of the load-bearing and stability behavior of thin-walled cold-formed steel sections as well as the presentation of current normative regulations and the new design concept, while verification is reserved for the second part.