ABSTRACT
ABSTRACT Welded steel tubular K-joints are widely used in bridges. The tubular joint usually encounters the problem of stress concentration at the weld vicinity. Fluctuating loads due to traffic causes fatigue problem where small cracks initiate at the location of the maximum stress concentration. Concrete filling the tube reduces stress concentration and hence, increases fatigue strength of the joint. In the current study experimental investigation of stress concentration factor (SCF) in circular hollow section concrete-filled steel tubular (CFST) K-joints with gap under balanced axial loading has been conducted. The distribution of SCF around the welded brace-to-chord intersection on both the brace and chord has been investigated in one CFST K-joint specimen. The experimental SCF results have been compared with the predicted SCF in empty and CFST K-joints. A finite element model has been developed using ABAQUS. Modelling SCFs are comparable with the experimental SCF results. The results have shown that the concrete has a significant effect in reducing the SCF.
