Random vibration life analysis of typical metal joint structures

In the field of aeronautical engineering, the vibration environment of aircraft structures is highly prone to inducing structural fatigue failure, which can lead to operational dysfunction and even catastrophic accidents. Structural fatigue damage is irreversible; once initiated, it cannot be eliminated and will accumulate continuously under continued loading. Additionally, fatigue failure typically occurs without obvious plastic deformation, making it difficult to detect, and its occurrence often leads to devastating consequences. Therefore, research on vibration fatigue life estimation for aeronautical structures holds significant engineering value. This study focuses on a typical metal joint structure in practical engineering. Frequency response analysis and random vibration analysis were conducted using MSC. Patran & Nastran and random vibration fatigue life were calculated via Matlab programming. The critical locations of the metal joint structure under random vibration loads were identified, enabling the prediction of its random vibration fatigue life. Durability vibration tests were subsequently performed on the joint to validate the simulation results. The error between the simulated fatigue life prediction and experimental results was 12.8%. Scanning electron microscopy (SEM) images confirmed consistent fracture locations and identified the failure type as fatigue fracture. The analysis methodology, simulation, and experimental results presented in this paper can serve as a reference for the strength design of similar joint structures.