Lightweight, optimized vehicle designs are paramount in helping the automotive industry meet reduced emissions standards. Self-piercing rivets are a promising new technology that may play a role in optimizing vehicle designs, due to their superior fatigue resistance compared with spot welds and ability to join dissimilar materials. This paper presents a procedure for applying the mesh-insensitive Battelle Structural Stress Method to self-piercing riveted joints for fatigue life prediction.
Additionally, this paper also examines the development of an interim fatigue design master S-N curve for self-piercing rivets. The interim fatigue design master S-N curve accounts for factors such as various combinations of similar and dissimilar metal sheets, various sheet thicknesses, stacking sequence, and load ratios. A large amount of published data was collapsed into a single interim S-N curve with reasonable data scattering. Using the Battelle Structural Stress Method and the interim S-N curve approach, fatigue lives of riveted locations can be reliably predicted.
This method is mesh-insensitive and employs a simplified modeling procedure which uses shell and beam elements to represent sheet metal and self-piercing rivets. Therefore a full vehicle body finite element analysis containing a large number of self-piercing rivets can be analyzed efficiently.