Local flange buckling of trapezoid web profile

Abstract

Steel girders with a cross section of “I” shape has been used since the advent of structural steel material into the construction industry. Thus, various sizing of flange, web and stiffeners and welding specifications has been developed for this built-up section. The design specifications of this steel girder are also available in different standards and codes. Nowadays, steel girders with trapezoidal web profile has been produced and used in the steel construction industry. This type of steel girder is rather new in the industry but rapidly gaining popularity because of its increased laterally restraint effect due to the trapezoidal web profile. However, there has not been a standard way of defining the strength properties and design methods for these steel girders. For instance, the effect that the trapezoidal web contributes to the local buckling resistance of the compressive flange is still undefined. The main objective of this paper is to define the effect of the trapezoidal web profile to the flange under compression that is welded to it. This is followed by the sub-objectives like finding out the different effect resulting from different web corrugation angles and the spacing between corrugations. This project covers the flanges subject to compression, e.g. flanges in a column and the flange under compression in a steel beam. The flange is assumed to be simply supported on one side of the longitudinal edge and the other is free edge. This project was carried out in two phases. In the first phase, a test rig with customized fittings was set up to facilitate the experimental testing on both the flanges with plane web and corrugated web.