Joints subjected to high loading rates

In joining techniques, various types of joints, such as adhesive-bonded, bolted, hybrid, and pinned joints, are utilized. These joints can be employed mechanically and/or adhesively, depending on their designated applications. Adhesive bonding, a joining technique increasingly employed in recent years across diverse fields including automotive, aerospace, space, and defense industries, offers advantages such as enhancing mechanical performance at joints and improving predictability in damage mechanics. Given the critical importance of this area, our study was conducted to investigate adhesive bonding in comparison to other joint types intended for use in these fields. Our aim is to examine the effects of repeated loadings on the performance of adhesively-bonded single lap joints. Using both experimental and numerical approaches, a projectile with a mass of 1.25 grams and a density of 11.3 grams/cm3 was fired at a specially designed experimental setup at a velocity of 279.97 m/s, and the entire experiment was recorded with a high-speed camera. The single lap joints (SLJs) were manufactured from 6061 aluminum adherend (AA6061) material and were bonded with a thermosetting modified epoxy adhesive film (AF163-2K) produced by 3M Scotch-Weld™. The joints, with a thickness of 4 mm and an overlap length of 15 mm, were subjected to ballistic testing with 2 shots and 3 shots, followed by quasi-static tensile testing. When comparing the joints subjected to 2 shots and 3 shots with the non-impacted and 1 shot impacted ones, it was found that while the joints subjected to 2 shots with a 15 mm overlap length mechanically deteriorated, joints subjected to 3 shots experienced rupture at the end of the experiment. Theoretical information has been confirmed by experimental data. The inputs were analyzed in the ABAQUS program using the Johnson-Cook deformation parameters, and the experimental results were numerically validated within the program. Keywords: Joining techniques, adhesive joints, ballistic test.