Effect of damaged rivet head on the strength of aircraft joints

Solid rivets of type MS20470AD-4 which are widely used in aerospace structures are frequently preferred as structural fasteners due to their advantages such as mechanical strength, low weight, and ease of production. However, there is a limited number of experimental studies in the literature regarding the effect of material loss in rivet heads on the structural integrity of the connection. Based on this gap, the present study experimentally investigates the effect of decreasing rivet head height on the static shear strength of the connections. In this study, single riveted, single shear plane overlap joints prepared using 2024-T3 aluminum alloy were prepared with head heights of 0%, 25%, 50%, 75% and 100%, respectively, and static shear tests were performed by preparing ten samples for each group. The experimental data revealed in detail the effect of gradually reducing the rivet head height on the static shear strength of the joint. When the head height was reduced to 25%, 50% and 75%, no statistically significant difference was observed in the load carrying capacity of the joint in the shear direction compared to the control group with 100% head height. On the other hand, a significant decrease of approximately 11.3% in the carrying capacity was detected in the group where the head was completely removed. These results highlight the critical role of the rivet head in transmitting the load in a balanced manner and show that damage below a certain threshold value significantly weakens the stiffness and load-carrying capacity of the joint.