Load effects in beams with corrugated webs: Numerical study

Paper in proceeding, 2024

Corrugated steel web girders have emerged as a promising choice in bridge construction due to their benefits in reducing material. Fatigue is a common cause of failure in structures subjected to cyclic loading such as bridges. Evaluating the fatigue strength of corrugated web girders presents challenges due to the complex geometry and load transfer mechanism. Unlike conventional plate-girders with flat webs, the shape of corrugated webs affects the stress distribution in girder flanges when it is subjected to bending and shear. Previous research has noted the uneven stress distribution along the flange width. However, these studies have not distinctly separated the various load effects that collectively contribute to this uneven stress distribution. Such separation is particularly important for understanding the fatigue behaviour of these girders and identifying the relevant stress components to be used in fatigue design. The goal of this study is to identify different load effects in the flanges of corrugated web girders under bending and shear. Four finite element models of beams with corrugated webs loaded in four-point bending are constructed, validated, and the load effects from bending and shear are separated and analysed. The study identifies, besides the membrane stress effect, three bending load effects in the flanges.
The first bending effect is the transverse bending caused by shear flow. The second bending effect is local transverse bending caused by the uneven contribution of the web to the beam section modulus. The last bending effect is global transverse bending. These bending effects are influenced by various factors such as the number of the corrugations per shear span, where the support and load are positioned (whether on an inclined or flat fold), and the symmetry within the shear span. These variables collectively impact how stress is distributed in the flange, highlighting the complexity of the behaviour of corrugated web girders.