A Comparative Study of Pin Connection Methods in Aircraft Structural Assemblies

In the aerospace industry, pins are crucial for fastening multiple connected structural parts, ensuring a flush connection that does not protrude from the assembly’s surface. These pins are installed through various methods to meet stringent mechanical and anti-loosening requirements, essential for aircraft structural integrity. Typical pin installation techniques include clearance fit with punch point installation, small interference fit with punch point installation, large interference fit with punch point installation, and interference fit without punch point installation. This study examines the connection reliability and manufacturability of different pin assembly processes, focusing on load testing under operational conditions. Results indicate that a small interference fit (0-0.01mm) combined with punch point installation provides high connection reliability and ease of manufacture, with punch point methods notably enhancing loadbearing capability and assembly integrity. In contrast, larger interference fits (0.01–0.04mm) require complex manufacturing steps, such as liquid nitrogen cooling for cold shrinkage, and the use of a shaft press for assembly, which increases difficulty and risks damaging both pins and surrounding structural parts. This research provides insights into optimizing pin assembly techniques to improve the durability and performance of aircraft structural assemblies.