Effect of Welding on Lateral-Torsional Buckling Resistance of I-Shaped Built-up Steel

An experimental investigation was made of the inelastic lateral-torsional buckling of built-up steel I-beams. All beams were carefully fabricated with controlled levels of initial crookedness. Nineteen beams were tested in five groups under same loading conditions with two points load applied at the top flange. The results confirmed that built-up beams of intermediate slenderness with fillet welds on one side of the web are sometimes stronger than their counterpart beams with fillet welds on both sides of the web. It was found that design loads predicted by the Australian Standard provided good lower bounds estimates to failure loads of the tested beams.