Determination of Slip-factor Between Friction Shims and Shot-blasted Steel Surfaces

This paper presents the results of an experimental testing campaign performed to determine slip‐factor between the faying surfaces of shot‐blasted steel plates and state‐of‐the‐art friction shims. In total five experimental tests were performed as consistent with the provisions of EN1090‐2 Annex G to determine the slip‐factor between the faying surfaces. The results of the experimental test campaign showed that the surface roughness of the steel plates needs to be suitable for the selected type of the friction shims to enrich the slip‐resistance of the bolted‐connections. The test procedure was simulated with a commercial finite‐element analysis software, Abaqus, to compare the empirically determined slip‐factor and the penalty friction formulation of the software. It is shown that the slip‐factor definition of EN1090 – 2 Annex G fits in a very good agreement to the penalty friction formulation of the software to estimate the slip‐resistance of the bolted connections. The differences between the test results and the outputs of the finite element analysis are discussed in detail with a novel representation of non‐linear stick‐slip transition path for the slip‐resistant bolted connections. A further parametric study was performed to understand the impact of the geometric parameters on the slip‐resistance and the load‐slip behaviour of the faying surfaces.