Fatigue behavior and life prediction of self-piercing riveted joint

•SPRs of dissimilar metal sheets of AA6111-T4 and HSLA340 were investigated with under different load ratios.•There is a competition between rivet and aluminum sheet failure, and the latter one is the dominant fatigue failure mode.•A new structural load based crack growth approach was proposed and successfully applied on life prediction of SPR.

The fatigue behavior of self-piercing riveted joints of aluminum alloy AA6111-T4 and steel HSLA340 sheets has been experimentally and numerically investigated in present paper. Fatigue results reveal that the mating sheet stiffness and load ratio have significant impact on the fatigue strength, and the dominant failure mode under tensile–shear loading is eyebrow crack with an approximately semi-elliptical crack front. New stress intensity factor equations are derived for a semi-elliptical surface crack in a finite plate near a rigid cylindrical inclusion with axial shear force and bending moment, including the ratio of crack depth to crack length ranged from 0.2 to 1 and the ratio of crack depth to sheet thickness ranged from 0.2 to 0.8. A new structural load fatigue crack growth model is proposed, and predictions of fatigue lives and final crack aspect ratios show good agreement with experimental results.