Interference optimization method for riveted joints made by pneumatic percussive riveting on aluminum-lithium alloy sheets

Abstract

The adoption of aluminum-lithium alloy in aircraft has become prevalent due to its lightweight properties, which not only contribute to a reduction in CO₂ emissions but also enhance the aircraft’s dynamic performance and endurance. However, interference measurement during the riveting process on aluminum-lithium alloy sheets requires either destructive testing or reliance on non-destructive testing technology. This not only increases the workload but also decreases operational efficiency during the riveting process. To address this issue, the paper proposes an interference optimization method for riveted joints created by pneumatic percussive riveting (PPR) on aluminum-lithium alloy sheets, which allows for the rapid determination of the optimal process parameter prior to the pneumatic percussive riveting operation. A case study demonstrates that the proposed optimization method yields a maximum discrepancy of less than 0.12 in riveting quality indicators when compared to the experimental results. In addition, a variance analysis is performed for both dimensions and interference of PPR riveted joint on aluminum-lithium alloy sheets. It is found that impact duration has the most significant effect on the dimensions of PPR riveted joints, followed by gas pressure and then aperture, with an interaction effect between impact duration and aperture. Moreover, the aperture and gas pressure significantly affect the minimum interference, with aperture having a more pronounced impact. A close match between aperture and rivet diameter yields larger minimum interference due to frictional resistance, while larger apertures and higher gas pressures enhance minimum interference. Gas pressure, aperture and impact duration significantly influence the interference range, with gas pressure having a more pronounced effect, followed by gas pressure and then aperture. A close match between aperture and rivet diameter results in a smaller interference range, whereas the lower gas pressure and longer impact duration leads to a larger interference range.