Development of a CAE Method to Predict the Fatigue Life of Aluminium Panels Joined by Self Piercing Rivets

Abstract Jaguar Land Rover were the lead partner in a three and a half year Technology Strategy Board (TSB) project to develop commercially available software simulation tools to predict the fatigue life of joints in aluminium (AA5754) sheet materials. Five joining technologies were investigated; Self-Piercing Rivets (Henrob SPR), Medium Frequency Direct Current Resistance Spot Welds (RSW), Structural Adhesives (Dow4601) and two combinations of these joining methods (Weld Bonded & Riv-Bonded). This project successfully developed fatigue damage models for all of these technologies. The generation of a damage model is not just a one off activity, but a continuous process of development and improvement. Each time a new material is included into an SPR joint, fatigue tests are conducted and the damage model revisited to verify whether the model is still valid or whether a new model is required. Changes in CAE joining methodologies used to model the SPR's, as well as difference in the CAE solvers used all require reconfirmation of the models. This paper reports the overall approach that was used order to establish and develop the fatigue damage model for just one of these joining technologies, Self-Piercing Rivets. The approach produced substantial execution and implementation time savings. This has enabled Jaguar Land Rover to improve their capability in terms of virtual CAE assessment of joint behaviour and performance. The acquired understanding of load propagation through the structure allows joint and part optimisation, while maintaining or even improving the overall product quality. This enables weight reduction with the environmental benefits this brings