LAUSR

Abstract Currently, corrugated web girders (CWGs) are important structural components in bridges. Besides, they act as crane carrying girders and extensively as frame members. Despite that considerable improvement has been made in the last decade in understanding the flexural response of CWGs, the effect of using slender flanges has been limited. In the literature, the beams are too short to exhibit the lateral-torsional buckling (LTB) mode, and they merely focus on the local buckling (FLB) of the flanges. Accordingly, this paper focuses on the influence of slender flanges on the LTB behaviour of CWGs, with the main goal of assessing the suitability of the current EC3 design model. Currently, these girders have been examined through numerical modelling with the aid of ABAQUS software. Firstly, the numerical models have been carefully validated. Then, parametric studies have been carried out considering the influences of the material grade besides the cross-sectional dimensions on the structural response of CWGs that act as crane carrying girders or frame components. The results show that FLB might be accompanied by a slight LTB in intermediate-length girders, while FLB and LTB take place in short and long girders, respectively. The strengths of the current girders have been checked against the predictions of EC3 and it is found that it should be enhanced for the efficient design of such girders. Therefore, a modification has been proposed for such design model, which has shown to provide better strengths compared with numerical and available test strengths which in turn provides weight savings. Additionally, several conclusions have been presented to structural engineers to help in designing efficient cross-sections.