DOE Analysis of the Effects of Geometrical Parameters on the Self-Piercing Riveting of Aluminium Alloy AA6060T4

The design of experiments (DOE) is a very useful tool to design and analyze complicated industrial design problems. They help to understand the variability a manufacturing process by investigating which parameters and their interaction mainly affect the output repeatability. As a consequence, it enables to individuate the combination of parameters that optimize the output avoiding misinterpretation that can be due to the singularity of the experimental data. In this study the factorial analysis was used to investigate the effects of the major geometrical parameters on the shape of the force-displacement curve of the self piercing riveting (SPR) process. A full two level three-factorial design (23) was completed, three-way interaction was not considered. The statistical analysis was carried out at four different points of the force-rivet displacement curve. These points can be considered critical since they limit the four steps in which the process is commonly divided for studying purpose. The experimental data did not fulfil the required design points, the missing points were obtained by a finite element model of the riveting process, which furnished the force versus the rivet run.