Instantaneous mechanical fastening of quasi-isotropic CFRP laminates by a self-piercing rivet

A modified self-piercing rivet (SPR) has been proposed to mechanically fasten CFRP laminates. The modified SPR consists of a rivet body and two flat washers. The two flat washers were used to suppress delamination in the CFRP laminates at the point of piercing. The advantages of the modified SPR for fastening CFRP laminates are instantaneous process time and low cost. Any pretreatments such as surface treatments or hole drilling are not required. In this study, the viability of the modified SPR for a quasi-isotropic CFRP laminate was investigated by tensile and fatigue tests on the single lap joints. The experimental results showed that the tensile strength of a modified SPR joint was slightly higher than a bolted joint. In tension–tension fatigue tests, a fatigue limit at Nf = 107 cycles was about 50% of the tensile joint strength. Experimental results showed that the modified SPR was one of the promising fasteners for future mass-production CFRP automobiles.