Web slenderness effects on flexural behaviour of compound normal and high-strength steel beams

This paper discusses web slenderness effects on the flexural behaviour of epoxy adhesive-bonded compound normal and high-strength steel beams. The compound beams were simply supported and consisted of an I-section connected, on its top flange, to a channel section via an epoxy adhesive. A nonlinear 3D finite element modelling study has been performed using ABAQUS software for the analysis of the beams. The nonlinear finite element modelling was verified against tests on compound steel beams having different cross-sections. An extensive parametric study was carried out using the finite element modelling to study the effects of the change in web slenderness, cross-section geometries, beam lengths and steel strengths on the flexural behaviour of compound steel beams. The failure moments predicted from the finite element modelling were compared with the design moments predicted from the European code for steel beams in flexure. It is shown that the Code, generally, overestimated the design failure moments for most of the epoxy adhesive-bonded compound steel beams investigated in this study. In addition, reliability analysis was performed to assess the reliability of the design rules of the code. Generally, it is found that the European Code is unconservative and statistically unreliable for the epoxy adhesive-bonded compound beams investigated in this study.