Buckling capacity of pretwisted universal beam sections

摘要

In this paper, pretwisting is applied to structural steel beams in an attempt to improve their critical buckling capacity. This paper presents an experimental investigation of the buckling load capacity of pretwisted UB100×50×9 beams of 1-m length. The objective is to examine the effect of pretwisting on the buckling capacity of structural steel beams under pure axial compression. A universal testing machine with a capacity of 1200 kN was used to test the buckling load capacity. Four different pretwist angles, 15°, 30°, 50°, and 60°, are considered and their beams' buckling loads are compared to that of the prismatic beam. It is shown that pretwisting up to a certain limit can improve the axial strength of the pretwisted beams. The beams with pretwist angles of 15° and 30° showed significant improvement in buckling load capacity, while those pretwisted at 50° and 60° showed slight deterioration.