Prediction of a clinched joint strength of dissimilar aluminium alloy sheets based on ductile rupture model

Abstract

This article investigates the clinching process for joining dissimilar aluminium alloy sheets, focusing on the prediction of joint strength using an uncoupled rupture criterion. Clinching is a mechanical sheet metal joining technique that does not require additional materials, making it efficient for use in industries like automotive manufacturing, where weight reduction is critical. In the present study finite element analysis (FEA) based numerical simulations were developed, to explore the formation and strength of clinched joints between two aluminium alloys, AA5182-O and AA6016-T4, which are known for their anisotropic properties. A key aspect of the research is the calibration of material models using a hybrid experimental-numerical approach. The study incorporates advanced yield criterion and hardening models (Yld2004-18p, combined Swift-Voce) and an uncoupled ductile rupture model (Lou2012) to predict damage and failure during the clinching process. Both 2D and 3D simulations are employed to assess the clinch joint formation, material flow, and joint strength under tensile-shear loading conditions. The simulations were validated against experimental results, showing the effectiveness of the considered models. The research highlights the challenges of accurately simulating clinched joints due to high plastic deformation and complex material behaviors. Moreover, the importance of integrating material anisotropy and damage models in predicting the performance of clinched joints under operational stresses are discussed. This work advances the understanding of clinch joint behavior, particularly for dissimilar materials, and provides insights for improving joint quality and strength prediction through enhanced simulation techniques.