Abstract

In this work, aspects concerning the behaviour of steel joints under combined actions are investigated. Adopting the philosophy of the component method the attention focused on the analysis of a basic component of the connection: the T-stub. Research works carried out in the recent past extensively investigated the T-stub response under tension, while no data are available for the T-stub's response under combined tension (N) and shear force (V). In the thesis experimental, numerical and theoretical studies on this topic are presented. The starting point is the experimental activity carried out at University of Trento on column T-stubs under different combinations of axial and shear force. The experimental outcomes strongly highlighted the influence of the loading conditions on the strength and deformation capacity of the T-stub. In a second phase 3D numerical models were developed and calibrated to reproduce the actual behaviour of the T-stubs. The numerical simulations were then extended to different specimen geometries to investigate the main geometrical parameters which could affect the T-stub response. On the basis of experimental and numerical data a theoretical model based on limit analysis was then developed. It allows predicting a simplified load-displacement curve of the T-stub under a generic combination of N and V. The results obtained from the analytical model seem to reproduce with sufficient accuracy the complex behaviour of the T-stub, allowing to appraise the elastic stiffness and the yield load.