Fatigue behaviour of welded thin CHS-plate T-joints under in-plane bending

摘要

Thin cold-formed circular hollow section (CHS) tubes were fillet-welded onto a plate forming a base plate moment connection. The tubes are of thicknesses 3.2 mm, 2.6 mm and 2.0 mm. The resultant CHS-Plate T-joints were tested under cyclic in-plane bending moment. Brace-Tension Side failure was observed in the welded thin-walled CHS-Plate T-joints. The scatter of the S-N data for the different tube wall thicknesses at a given nominal stress range showed that the fatigue life in relatively thicker welded tubes is greater than the fatigue life in relatively thinner welded tubes for thicknesses less than 4 mm. The resultant fatigue S-N data of CHS-Plate T-joints under in-plane bending lies above the design S-N curve of the tube-plate T-joints made up of thin-walled (t < 4mm) square hollow section (SHS) tubes under in-plane bending.