Experimental analysis and mechanical modeling of T-stubs with four bolts per row

The behavior of steel structures is significantly affected by the connections between the steel members. For this reason, special attention to the prediction of the joint rotational behavior is devoted by Eurocode 3 which provides the well-known component method. In EC3, starting from the results of several researches, the formulations for the characterization of the behavior of T-stubs with two bolts per row are given, but with reference to T-stubs with four bolts per row, even though they are present in many actual structural situations, the limited number of experimental tests and analytical models has not led yet to the codification of this component in the code. In this work, starting from the results of three experimental tests on T-stub with four bolts per row, carried out at the laboratory on materials and structures of the University of Coimbra, a FE model in ABAQUS has been set up in order to analyze the yield line patterns corresponding to the different collapse mechanisms. Subsequently, with reference to the yield line shape different from that of T-stub with two bolts per row, the effective lengths have been revaluated applying an energy approach. The definition of the effective width for all the possible collapse mechanisms allowed to set up a proposal for determining the resistance of T-stubs with 4 bolts per row consistent with the approach provided by Eurocode 3. The model accuracy has been verified by means of a comparison with the results provided by a numerical analysis