Shear resistance of austenitic and duplex stainless steel bolts

Abstract

The current design rules in EN 1993-1-4 for non-preloaded stainless steel bolted connections under pure shear and tension (specified as category A and category D connections acc. to EN 1993-1-8) are essentially based on the regulations for carbon steel bolted connections. However, bolts made of stainless steels have in principle a different load bearing behaviour compared to carbon steel bolts and should be investigated systematically and considered in the design rules. For this reason, research activities have been carried out within the German research project “Load-bearing capacity of bolted connections loaded in shear and tension made of stainless steel M12 to M36” (IGF-No. 20651 N). Herein, experimental investigations and a literature review into the load bearing behaviour under pure tension and single-shear has been carried out to evaluate the resulting shear coefficients α for austenitic and duplex stainless steel bolts of property classes 50 to 12.9 as a basis for implementation in the revision of EN 1993-1-4. Furthermore, a reliability analysis according to EN 1990, Annex D has been carried out to prove the partial safety factor of γM2 = 1.25 for connections. On this basis, new shear coefficients α could be proposed which allow a more economical design of non-preloaded bolted shear connections.