Effect of Sheets’ Thickness and Rivet Geometry on Mechanical Properties of Orbital Riveted Aluminium Joints: Experimental and Numerical Analysis

Orbital riveting is an innovative joining technology used in various industrial fields. Despite its diffusion in recent years, it has not been accompanied by an equivalent interest from the scientific community, which has neglected the aspects of process optimization and joint performance. In this experimental/numerical study, six different configurations of orbital riveted joints were realised and tested to determine the effects of sheet thickness and rivet geometry on the mechanical properties of the joints and their failure modes. The results showed that the configuration of the joint significantly affects both its resistance and fracture mechanism. Moreover, it was possible to identify a transition between different failure modes by changing the rivet diameter. A non-optimal joint geometry favours a premature fracture at very low load (i.e., S9A21 batch with net tension fracture). The highest mechanical resistance was found in the S8A15 batch, which experienced unbuttoning failure. In order to better correlate the joint geometry with the mechanical behaviour and the relative stress distribution, a simplified numerical FEM was validated with the experimental results.