Modelling of strengthened column web panel in bolted end-plate composite joints

This paper deals with the analytical modelling of the column web panel in steel and composite bolted end-plate beam-to-column joints. The strengthening of these joints by web doubler plates or haunches is investigated. A previous experimental programme carried out at INSA of Rennes-France has shown the limitation of the web panel design model proposed by Eurocode 3 part 1–8. In this paper, a new model is proposed where the main idea is the partition of the whole column web panel into sub-panels. This allows to take into account the non-uniform distribution of shear forces along the height of the column web panel. The behaviour of each sub-panel is described by an original non-linear spring model. This model is able to predict accurately both the elastic and inelastic responses of the sub-panels. The overall behaviour of the column web panel is then described by a spring serial system in shear where each spring represents a sub-panel. The model predictions are in good agreement with experimental results whereas the Eurocode model seems to be conservative.