BEHAVIOUR OF LAP SHEAR RIVETED CONNECTIONS WITH CONSTRUCTIONAL IMPERFECTIONS

Riveted connections are the most common structural details of existing steel bridges. Due to the increase of traffic loads as respect to the conditions at their erection time, existing riveted bridges are usually characterized by structural deficiencies and prone to fatigue damages. Moreover, the structural inadequacies are often magnified by the presence of peculiar constructional defects (i.e. shank misalignment, forged head distortion), which induce local stress concentrations that further reduce the service life. In this paper, the behaviour of riveted lap shear connections under static and cyclic actions is investigated by means of finite element (FE) simulations. The investigated connections are representative of typical geometries of the details of actual existing railway bridges. FE models were calibrated against the results of former tests drawn from literature. In addition, the FE models allowed at investigating the influence of constructional imperfections on the ultimate static and fatigue resistance and of the connections. In order to widen the parametric study, the following parameters are varied, namely: (i) number of rivets, (ii) diameter of rivet shank, (iii) thickness and width of the plates.