Welded‐Tee end Connections for Circular Hollow Tubes

The paper investigates, theoretically aand experimentally, the behavior of welded‐tee end connections for circular hollow tubes in tension. Elastic stress distributions around the tube walls below the cap plate are derived. The results show that maximum stresses in the tube below the cleat‐plate corners may be reduced if thicker or narrower cleat plates are used. A total of 21 end connections having various combinations of 8 mm and 12 mm cap and cleat‐plate thicknesses on three tube sizes are tested. The observed first‐yield load, the ultimate load, and the mode of failure are reported for each test specimen. It was found that apart from possible weld defects failure of the end connections is either by local fracture in the tube below the cleat‐plate corners, or by tube yielding if thick enough cap and cleat plates are used. Results reveal that considerable stress redistribution occurs in the test specimens before failure. A simple design approach based on a 60° spread of load through the cap plate is proposed.