Lap joint

Residual stress

Rivet

Structural engineering

Engineering

Fatigue limit

Joint (building)

Composite material

Metallurgy

Materials science

Shot (pellet)

Shot peening

Peening

Journal of Materials Research and Technology

The joint strength of self-piercing riveting is a key factor for evaluating riveting quality. Shot peening is a useful process to strengthen sheet metal. To improve the performance of self-piercing riveting joints, the shot peening process and self-piercing riveting process are combined in this work. The shot peening of AA5052-H32 aluminum alloy sheets, static and fatigue experiments of the self-piercing riveting joints are executed, the effects of shot peening on the mechanical performance of the joints are performed. The results show that: The shot peening process can induce residual compressive stress in the surface layer of aluminum sheets, which can improve the performance of the joints; In the shot peening process, the largest residual stress is around −187.3 ± 5.1 MPa; The shot peening process can improve the static strength of the joints by about 9.5%, and has little effects on the tensile failure forms of the joints; The fatigue strength of the shot-peened self-piercing riveting joints is increased by about 9.2%. The main fatigue failure type is the damage of the lower sheets at the contact zones with the rivet leg. The contact surfaces for the shot-peened self-piercing riveting joints are suffered less from the fretting damage than that of non-shot peened joints. The static strength, fatigue strength are increased, and the fatigue crack growth rate is decreased for shot-peened joints. The shot peening process can be innovatively combined with the self-piercing riveting process to improve self-piercing riveting joint performance. This work provides new ideas to improve the self-piercing riveting quality.

Effect of shot peening on static and fatigue properties of self-piercing riveting joints