화학공학소재연구정보센터
Journal of Adhesion, Vol.95, No.5-7, 577-594, 2019
Fatigue behaviour of hybrid clinch-bonded and self-piercing rivet bonded joints
Hybrid joints consist of mechanical connections in which both a traditional mechanical joint (i.e. riveting, clinching, welding) and adhesive bonding coexist in order to obtain a better performance if compared with simple bonded or mechanically connected joints. Several literature works demonstrates how hybrid joining allows to improve strength, stiffness and energy absorption in comparison with simple mechanical or bonded connections. In this work the static strength and, more in deep, the fatigue behaviour of clinched, self-piercing riveted, adhesively bonded, clinch-bonded and self-piercing rivet-bonded single lap joint were experimentally investigated for aluminium adherends.It was observed that the static strength of the clinch-bonded and self-piercing rivet bonded joints was essentially due to the adhesive layer, with small decreases due to the reduction of the bonded area related to the presence of the fastened connection.Concerning the fatigue tests, different results were found, in particular it was detected that hybrid joints performed worse than simple joints (especially as regard to the bonded joints) at low number of cycle, while they performed significantly better for high number of cycle.The evolution of the joints damage was monitored by optical observation and by measuring the compliance; it was found that, in the hybrid joints, the presence of the mechanical fastening significantly reduced the crack growth rate in the adhesive layer, with respect to the one of the simple bonded joints, therefore leading to a higher fatigue life.