Riveting Quality Improvement Mechanism of 2A10 Aluminum Alloy with Compound Feed Rates

The riveting process is conventionally performed at a constant feed rate, overlooking the distinct deformation mechanisms inherent in its successive stages. This study introduces a novel compound feed rate approach to enhance the riveting quality of 2A10 aluminum alloy countersunk head rivets. A three-dimensional finite element model, validated experimentally, was developed to simulate the riveting process, segmented into three stages: free upsetting, hole wall interference, and driven head formation. An orthogonal experimental design was employed to investigate the effects of varying feed rates (1, 5, 10 mm/s) within these stages on key quality metrics: interference distribution, uniformity, and driven head geometry. Results demonstrate that increasing the feed rate reduces average interference but increases the driven head diameter, revealing a stage-dependent influence. A multi-objective optimization framework, integrating gray relational analysis with the entropy weighting method, was applied to balance these competing objectives. The optimal compound feed rate scheme of 10-1-10 mm/s (for the three stages, respectively) was identified. This optimized scheme improved interference uniformity by 1%, increased the critical shank-end interference (Point H) by 10.9%, and enhanced driven head dimensions compared to conventional constant-rate riveting.