Abstract:
In order to investigate the effect of loading rate on the tensile properties of GFRP/Al bonding-riveting hybrid joints, bonding-single riveting and bonding-double riveting hybrid joints were selected as the research subjects. Dynamic tensile tests were conducted at loading rates of 0.5 m/s, 1.25 m/s, and 3.75 m/s, respectively. The load-displacement responses, peak load, and energy absorption of the two types of joints under different loading rates were analyzed. The failure process was recorded and analyzed using digital image correlation (DIC) technology, and the fracture morphology was examined via optical microscopy. The results indicate that the tensile force-displacement curve of GFRP/Al adhesive riveted joints encompasses the overall load-bearing capacity, adhesive layer failure stage, rivet load-bearing capacity, and joint failure stage; Increasing the loading rate exhibited no significant effect on the peak load and energy absorption. The average peak load and energy absorption of the bonding-single riveting hybrid joints remained within 3.3 ~ 3.7 kN and 13.2 ~ 13.7 J, respectively, while those of the bonding-double riveting hybrid joints remained within 6.2 ~ 6.4 kN and 26.6 ~ 30.4 J. Furthermore, the failure modes of the bonding-riveting joints showed sensitivity to the loading rate. At high loading rates, fracture and warping of the GFRP laminates at the joint region were identified as the primary failure modes. Compared to joints tested at low loading rates, interlaminar failure of the GFRP laminates was more severe, and the fracture morphology appeared more regular.