2D FEM model for predicting the ultimate behaviour of bolted T-stubs

The prediction of the behaviour of beam-to-column connections can be obtained by means of the so- called “component method”, largely used in research studies and currently codified in Eurocode 3.The main feature of this approach is its ability to account for any kind of connection, provided that the basic components of deformability and strength are properly identified and modelled. The most important components of beam-to-column joints can be modelled by means of equivalent T-stubs, i.e. two equivalent T-shaped elements connected through the flanges by means of one or more bolt rows. In order to predict the T-stub behaviour, simplified theoretical models are provided by Eurocode 3 which allow to evaluate the T-stub stiffness and resistance. Conversely, there are no codified rules to predict the plastic deformation capacity. Therefore, methods for predicting the T-stub ductility in have been proposed in previous works [1-4]. Other mechanical model for modelling of stiffness of bolted T-stub connection components have been illustrated [7]. In addition also the modelling of the T-stub cyclic behaviour has been investigated [5]. It can be observed that, even though theoretical models are very important in order to recognize the parameters which govern the stiffness, resistance and ductility of bolted T-stubs, they are not easy to be applied for predicting the overall monotonic and cyclic behaviour. For this reason, in this paper, a simple 2D FEM model representing the T-Stub behaviour has been developed using SAP2000 computer program and the accuracy of this approach has been verified by means of a comparison with available experimental results. In addition, the comparison between the proposed FEM model and the theoretical models previously proposed has been performed.