Behaviour of high-strength CFDST chord to CHS brace T-joint: Experiment

Abstract This paper presents an experimental investigation on the fatigue behaviour of composite T-joints which consisted of circular concrete-filled double-skin steel tubular (CFDST) chord and circular hollow section (CHS) brace, with the high-strength steel used in the chord. The test parameters included the brace to chord diameter ratio, the hollow ratio of the chord and the load range. The brace was subjected to repeated cyclic tension and the development of cracks in test specimens were recorded. The measured fatigue lives were compared with predicted ones using current codes of practice. It is found that the fatigue life of CFDST T-joint was underestimated according to codes for hollow section steel T-joints or joints who have grout between annulus of chord.