Experimental investigation of SCF distribution for thin-walled concrete-filled CHS joints under axial tension loading

• A series of tests on the thin-walled concrete-filled tubular T-, Y-, K- and KT-joints under axial loading is presented in this paper.
• The test specimens thus include two different chord wall slenderness ratios (D/t=75 and 60).
• The stress concentrate factors of thin-walled concrete-filled tubular T-, Y-, K- and KT-joints under axial loading were obtained.
• The suitability of design equations specified in current API Standard, LR Guide and DNV manual for the thin-walled concrete-filled tubular CHS joints was evaluated.

This paper aims to study the stress concentration factors (SCF) of thin-walled concrete-filled circular hollow section (CHS) T-, Y-, K-, and KT-joints subjected to axial tension loading. Experiment was performed to investigate the Hot Spot Stress distribution along the intersection of chord and brace. Eleven test specimens with self compacting concrete filled in the chord were tested. Test results indicate that the stress distribution is mainly determined by joint type, while the chord thickness has little effect on it. The stress concentration factors obtained from the test results were compared against predictions from some of the well-established existing equations for steel joints. Generally, the predictions from those equations are very conservative.