Bearing capacity of headed studs under combined tension and shear loading in composite beams with large web openings

The use of steel‐concrete composite structures with a high installation grade is becoming increasingly popular in building and industrial construction. To reduce construction height building services are routed through web openings in the girders. However, these openings represent local points of interference where, in the case of composite girders, parts of the acting shear forces are transferred from the web of the steel profile into the concrete slab. This results in additional, local stresses in the remaining steel girder and in the concrete chord, which must be considered in the design of the floor girders and shear connectors. Web openings in composite girders are not addressed in the current European design standard for steel‐concrete composite construction (EC 4). Only with the introduction of the second generation of Eurocodes in the coming years this case will be normatively regulated. During the preparation of the standard further questions about the load‐bearing behaviour arose, as the existing design approaches usually only consider a selection of possible failure scenarios or neglect essential verification steps. A joint research project between the University of Kaiserslautern‐Landau and RWTH Aachen University aims to develop a suitable design concept for composite girders with web openings. Model and beam tests accompanied by numerical simulations will provide further information on the complex local and global load‐bearing behaviour of the composite girders.

This paper presents the results of experimental investigations and numerical simulations on the influence of large web openings on the global load‐bearing behaviour of the shear connectors in the composite joint. Based on 60 pull‐out tests and numerical simulations, the load‐bearing behavior of head bolt anchors under combined shear and tensile loading was researched and evaluated.