ABSTRACT
A numerical study of the behaviour of various bearing type bolted steel lap connections is presented. The aim of the investigation was to obtain and compare the numerical static response of the analysed connections with shear planes passing through threaded or unthreaded portions of the bolt shank. The analysis was directed at describing the stiffness parameters for each arrangement, with a distinction for the actual phases of bearing type bolted lap connection performance, including friction-slip mechanism. The study was initiated on the basis of a validated, referential connection and extended to a wider range of cases. The scope of the study covered models with one and two bolts and two shear planes. Several representations of the bolt shank geometries corresponding to the analysed cases were introduced. Additionally, the Gurson-Tvergaard-Needleman model for porous materials was introduced. Finally the numerical results were compared to the analytical ones derived from the component method, including linear and non-linear approaches based on the proposed second generation of EN-1993-1-8. Connections with unthreaded shank parts in bearing presented up to 60% greater stiffness at the initial contact phase comparing to full-threaded variants. Regarding the analytical relationships, a satisfactory fit was obtained for the linear approach, while the non-linear description of bolt embedment did not show sufficient agreement with both experimental and numerical results.
