Shear behavior of the connexion system of steel-concrete-steel composite structure: modelling of a push-out test
Résumé
Strength, stiffness and durability requirement for civil engineering constructions are steadily increasing. To fulfil these new needs, studies are launched to develop new structural materials with higher specifications. Steel-concrete-steel (SCS) composite structures are one of them. They are based on a concrete core that is caught between two steel plates. The efficiency of this type of structure comes from the connexion system, generally performed through steel dowels and/or ties. It provides a bond between the steel plates and the concrete core and is responsible for the overall behaviour of the SCS structure. The connexion system is generally designed to obtain a full composite action and is influenced by the shear resistance of the dowels, which is experimentally obtained through push-out tests [4]. This study focuses on the simulation of these push-out tests. A simulation methodology with 3D finite elements is first presented and validated on experimental results [5], as a reference model. A zero-dimensional simplified model is then proposed to decrease the computational cost for applications to structural test cases. It supposes the definition of a constitutive law between the shear stress and the slip between the steel plates and the concrete core, which is obtained from [6]. It includes in the same element the shear behaviour of the connectors but also the crushing of the concrete and the yielding of the plates around the connection system. This model allows to reproduce the experimental results with a lower computation cost compared to the 3D reference model.