Development of an end-to-end simulation process chain for prediction of self-piercing riveting joint geometry and strength

Self-piercing riveting (SPR) is one of the advanced mechanical joining techniques used intensively in modern automobiles. SPR is a cold forming process involving a semi-tubular rivet as fastener to join two or three similar or dissimilar materials. The present study deals with the development of a five-step simulation process chain capable of numerically predicting the SPR joint geometry and the joint strength under different loading conditions such as Shear, Cross-tension and Peel loading. The complete process chain considers a 2D axisymmetric model for the process simulation and a 3D simulation model with solid-shell interaction for the joint failure simulation. The calibration of damage models and their application in the joint strength analysis are integral parts of the present study. The comparison of joint strength analysis results with experiments under the criteria: mode of joint failure, maximum force (indicating joint failure) and displacement at maximum force provides basis for validation of the simulation process chain. Additionally, a comparison of joint geometry with joint cross-section images and force-displacement curves from experiments provides an opportunity for an intermediate verification of the numerical process flow. The study also presents an accuracy comparison of different damage models and the impact of rivet setting depth on the joint strength and mode of joint failure.