Lateral Torsional Buckling Strength of Partial Corrugated-Web Steel Beams

Abstract

Researchers and engineers concluded that corrugated webs significantly increase steel beams stability against lateral torsional buckling and can result in very economical design. While beams with trapezoidal web corrugations have been used in various structural applications and bridges, lateral torsional buckling of trapezoidal web beam still needs to be investigated. A Trapezoid web profile steel beam is built up by welding flanges and a web of trapezoidal corrugated profile in the longitudinal direction of the beam. The Shape of the beam web plate leads to the increase of the beam lateral stiffness when compared to flat web beams. Additionally, the different parts of the web plate will stiffen each other to resist shear buckling, thus it allows the use of thin plate webs without the need of stiffeners. The main advantages of using corrugated web steel beams in particular are; increase the out-of-plane stiffness, increase the lateral torsional buckling moment, increase the shear buckling strength and improves their fatigue life. The higher resistance of lateral torsional buckling, the elimination of vertical stiffeners and ease of fabrication leads to reduce considerably the overall construction cost of steel beam. PCW steel beams would have advantages over FCW steel beams by reducing the welding path and providing a flat portion in the web to facilitate connections of transverse beams. With the advanced fabrication technology, fabrication of partial corrugation in the web is not a challenging task. The objectives of the research presented in this thesis are to propose analytical expression for the wrapping constant of partial corrugated web PCW steel beam and investigate the effects of different geometric parameters on the lateral torsional capacity of PCW steel beams. The parameters shall include the corrugation angle, the corrugation ratio, the flat parameter ratio, the beam span and depth and web thickness.