Improving the ductility of welded connections in rectangular hollow sections

This paper presents an effective and economical solution that significantly increases the bending ductility of welded connections in Rectangular Hollow Sections (RHS). It can be applied to new as well as existing structures. It involves the use of extra layers of weld on the tension flange of the connected RHS. Laboratory test results are presented to demonstrate that the solution substantially increased the ductility of welded moment connections in cold-formed inline galvanised RHS. The reason why the solution results in increased bending ductility is explained in terms of strain redistribution and strain reduction in the tensile regions around the welded end of the RHS. The same factors indicate that the solution can increase the seismic ductility and the fatigue strength of welded connections in RHS.