Research of joints in structures with thin walled closed cross-section members

Joint types have vital role in process from design to mounting of steel structure members consist of thin walled closed cross-section profiles (Rectangular and circular hollow sections). The most important factor for fabrication procedure and capacity of connection is joint type. In this study, end fittings of rectangular and circular hollow sections, weld commonly used on structurel hollow section joints as a connecting equipment and capacity calculation of main joint types were researched. Calculation of joints was approached by inspection-analysis of weld sufficiency and checking failure modes such as punching and plastification of chord. Capacity formulae of joint types for rectangular and circular hollow sections were evaluated under seperate sections because of dissimilar behaviour under loading. Additionally, joint efficiency factors, which make fast design possible in preliminary phase, are given for main joint types. Parameters such as material quality, angle between bracings and chord, width to wall thickness ratio, diameter to wall thickness ratio were investigated and joint types were compared with each other. End fittings and welding preparations necessary for constituting joints were explained. Key Words: Rectangular and circular hollow sections, joint types, end fittings and welding preparations, capacity of joints