Effect of low-velocity impact on mechanical property and fatigue life of DP590/AA6061 self-piercing riveted joints

The low-velocity impact behaviors of DP590/AA6061 self-piercing riveting (SPR) joints are studied at the impact energies of 5 J, 10 J, 20 J, 30 J, and room temperature (25 degrees C). The lap shear and fatigue tests, and the cross-sectional microscopies of joints are used to assess the mechanical property evolutions of the joints after low-velocity impact. The results show that the absorbed impact energies of SPR joints reach the critical value at an impact energy of 30 J, the exceeded impact energy causes crack failures in the sheets and decreases the interlocking performance of the joints. The static property and the absorbed energy of the SPR joints are reduced by 16% and 36% when the joints are impacted at 30 J, respectively. The low-velocity impacts do not change the failure forms of the joints, but significantly reduce the mechanical interlocking properties of the joints. The fatigue lives of the SPR joints are reduced due to low-velocity impact, and the impacted joints are more sensitive to cyclic loadings.