Shear contribution of flange dowel action in steel–concrete–steel​ composite structures

The shear contribution of flange dowel action in steel–concrete–steel composite structures is studied in this paper. Tests on the shear behaviour of beam-type specimens are carried out, to complement existing experimental results, with particular focus on investigating the influence of flange thickness. Various methods for evaluating the shear resistance are discussed, and a detailed beam-on-foundation procedure is then developed considering both the elastic and plastic characteristics. The suitability of beam-scale numerical models for representing dowel behaviour is also examined, and a local-scale dowel model is constructed and employed in numerical parametric studies in order to calibrate an analytical beam-on-foundation approach. The parametric assessment includes a wide range of design variables and considers different cases of compression or tension foundations. The equivalent depth in concrete, flange yielding ratio, and supporting foundation strength ratio, are shown to be three key parameters governing the dowel stiffness and strength. Based on the theoretical and numerical findings, a simplified design method, that captures realistically the contribution of flange dowel action, is proposed and validated against a wide range of test data, including those from this study, and shown to offer highly reliable predictions.