Thermomechanical modeling of the metallic rivet in friction riveting of amorphous thermoplastics

The present work aims for an initial computational simulation with finite element analysis of the friction riveting process. Knowledge and experimental data from friction riveting of AA2024-T351 and polyetherimide supported the computational simulation. Friction riveting is a friction-based joining technology capable of connecting multiple dissimilar overlapping materials in a fast and simple manner. In this paper, the plastic deformation of the metallic rivet, process heat input, and temperature distribution were modeled and simulated. The plastic deformation of the metallic rivet is of key importance in creating the mechanical interlocking and main joining mechanism between the parts, being this the focus of this work. The influence of the polymeric material was considered a dynamic boundary condition via heat input and pressure profiles applied to the rivet. The heat input, mainly generated by viscous dissipation within the molten polymer, was analytically estimated. Three experimental conditions were simulated. The heat flux values applied in modeling of the different conditions were determined (8.2, 9.1, and 10.2 W/mm²). These yielded distinct plastic deformations characterized by a diameter of the rivet tip, from the initial 5 mm to 6.2, 7.0, and 9.3 mm. The maximum temperatures were 365, 395, and 438 °C, respectively.