General method for I‐section stainless steel beam‐columns

A significant progress in the development of stainless steel design procedures which were implemented also in new design standards proposals, prEN 1993‐1‐4:2021 and AISI 370‐21, has been going on in the last 15 years. For compressed members, buckling curves were revised and beam‐column interaction formulas were published for hollow and open sections. Buckling curve was significantly improved for double‐symmetrical I section beams. The Continuous Strength Method was introduced in the code. Also, a verification procedure using a plastic global analysis was developed and implemented in design procedures very recently. However, clear design rules for geometrically non‐linear analysis with equivalent member and structural imperfections need further research. This approach, known also as the general method, became a very popular method for carbon steel structures, but cannot be used for slender stainless steel structures without modification. The stainless steel nonlinear stress strain diagram leads to a reduction of the bending stiffness and thus higher second‐order effect, which needs to be covered in the procedure. In this research, a comparison is made on numerical parametric studies. Limits will be set for the applicability of the carbon steel design procedures and a preliminary recommendation for general method of stainless steel members will be presented.