Experimental Study of Detail Fatigue Rating of Bolted Joint Structures

ABSTRACT This study investigates the fatigue strength of an “L”‐shaped bolted joint structure subjected to complex loads on a specific aircraft model. Through the design of experiment specimens, finite element simulations, fatigue experimenting, and theoretical analysis, a comprehensive evaluation of the structure's fatigue performance was conducted. Finite element analysis was employed to simulate the stress–strain distribution and load transfer characteristics under various loading conditions. Fatigue experiments were then performed to validate the simulation results and assess the fatigue life under specific service scenarios. The results revealed that stress concentration at the bolt hole edge is the critical site for fatigue crack initiation and the primary cause of structural failure. A comparative analysis using the Design Fatigue Rating (DFR) method demonstrated good agreement between experimental data and theoretical predictions, confirming the method's applicability. Additionally, the length of the aluminum alloy plate and the magnitude of the applied load had minimal impact on the inherent fatigue performance, while reducing stress concentration at critical locations significantly improved fatigue life.