Welded Thin-Walled RHS-to-RHS Cross-Beams under Cyclic In-Plane Bending

Galvanized sections are suitable for use in the road transportation industry, the agricultural industry and for recreational structures. The structural systems in which galvanized sections can be used include chassis boxes, roof frames, base frames and drawbars among others. These structural systems are subjected d to cyclic loading in service. The structural systems are therefore prone to fatigue failure. In Australia, galvanized sections, commonly known as DuraGal, are thin-walled with wall thicknesses less than 4mm. There are currently no fatigue design rules for sections of thicknesses less than 4mm. The connections under investigation namely cross-beam connections, are not covered in current fatigue design guidelines. This paper reports on fatigue tests of cross-beam connections made up of galvanized rectangular hollow sections (RHS). The fatigue test data in the present investigation is compared to data from previously reported work on galvanized cross-beam connections. Stress concentration factors have been determined in a typical connection to verify the crack pattern observed in these connections.