Simulation of the solid rivet installation process

The riveting process with a solid rivet is one of the most applied joining processes in the aeronautic industry. New materials and new design requirements constitute challenges that drive the users to a better understanding of the installation process of riveted joints. Therefore, this study aims with the aid of FEM simulation to understand the phenomena occurring during the installation process and afterwards to predict the mechanical properties of the riveted joint depending on the installation parameters and characteristics of the adherends.The experimental installation process for the validation of the simulation model takes place in a fully automated C-frame riveting machine with all-electric drilling and riveting operations aptitude and continuous collection of process data. This paper deals with the simulation of the installation process. The simulation model consists of a solid rivet with universal head described by the standard EN6081 and aluminum (2024T351) ad herends. The rivet material model has been obtained by a compression test performed on specimens prepared from fasteners. The effect of friction was studied and a suitable friction coefficient identified. The developed installati onprocess model has been validated by comparing the simulation results with different experiments regarding the geometrical characteristics of the formed rivet head, the force-displacement curves and the surface residual strain of one adherend. Afterwards, the clearance fit between the rivet shank and the borehole, the rivet grip, and the squeeze force have been numerically studied in order to determine their effect on the joint. The effect of these parameters on the riveted joint is evaluated considering the residual stress and the residual contact force. The simulation of plastic deformation and residual stress state caused by the installation process provides a basis for the prediction of the mechanical properties of the riveted joint under external forces which is subject to ongoing research.