Electromagnetic dynamic self-piercing riveting (ED-SPR): A novel approach for enhanced dissimilar material joining

This study introduces electromagnetic dynamic self-piercing riveting (ED-SPR), an innovative technique that integrates electromagnetic riveting principles with static self-piercing riveting (S-SPR) for high-performance structural joints. A dedicated methodology and experimental apparatus for ED-SPR were systematically designed and validated. Quantitative comparative analyses between ED-SPR and S-SPR were conducted on three critical material combinations: CFRP/Al, low-strength steel HC340LA/Al, and high-strength steel DP590/Al. Key findings demonstrate that the electromagnetic-driven process reduces installation resistance by 60% and achieves a 30% larger interlock distance at the joint base compared to S-SPR. These quantitative advantages directly contribute to an approximately 30% increase in load-bearing capacity and superior damage tolerance in ED-SPR joints, as evidenced by tensile-shear testing of single-lap joints. Furthermore, distinct failure modes were observed: ED-SPR joints exhibited top plate pull-out failure in CFRP/Al and DP590/Al configurations, contrasting with the predominant rivet pull-out failure in S-SPR counterparts. Surface morphology and damage evolution were characterized via scanning electron microscopy (SEM) on post-assembly and tensile-failed specimens. The study establishes a foundation for optimizing electromagnetic-driven riveting parameters to mitigate CFRP delamination and further enhance joint reliability in vehicle body and aircraft fuselage structures.