Experiment investigation of stress concentration factor of concrete-filled tubular T joints

The aim of this paper is to study the stress concentration factors of concrete-filled tubular T joints subject to axial loading and in-plane bending. Experimental investigation was performed to investigate the Hot Spot Stress distribution along the intersection of chord and brace. Five tubular T joint specimens with self compacting concrete-filled chords were tested. In addition, three hollow steel tubular T joint specimens were also tested for comparison. Generally, it is shown that the concrete filling effectively reduces the peak stress concentration factors. The stress concentration factors obtained from the test results were compared against predictions from some well-established existing stress concentration factor equations. Generally, the predictions from those equations are very conservative for concrete-filled specimens.