A Design Model for Local Web Buckling in Tapered Composite Beams

Abstract

Steel-concrete composite flooring systems using steel sections with tapered webs are very attractive from an economical point of view, combining efficient use of steel, wide spans, rapid erection and easy access for services. However, the full economic exploitation of the composite tapered beam solution is inhibited by the limited understanding of certain aspects of its behaviour. One of the most pressing needs is for a better understanding of the local buckling behaviour of the relatively deep slender web at changes of slope in the lower flange. A design formulation has been developed which produces a very simple test of the need for stiffeners. This paper describes the derivation and behaviour of this design model. After that, a calibration of the model against some experiments and a parametric study is presented.