Modeling and analysis of reliability for the locking function of the water-dropping cabin door mechanism considering tribocorrosion effects

The water-dropping cabin door mechanism serves as a vital component in large amphibious aircraft designed for firefighting and rescue missions. The specific aircraft under study operates in harsh environments characterized by prolonged seawater immersion and tribocorrosion effects. Ensuring the reliability of the door's locking func tion is essential for successful mission execution. This study presents a systematic investigation into the reliability of the water-dropping cabin door locking mechanism. The current state of research in China on the reliability of such mechanisms is first reviewed. A rigid-flexible coupled multi-body dynamic model of the hatch mechanism is developed to determine the boundary conditions of the joints within the locking mechanism. Accelerated tribocorrosion tests are conducted on the mechanism’s joints to evaluate their tribocorrosion characteristics. Reliability simulation analysis is subsequently performed using the Adaptive Kriging Monte Carlo Simulation (AK-MCS) algorithm. The analysis reveals the degradation trends in reliability and reliability sensitivity under both dry friction and tribocorrosion conditions. The results offer valuable insights for improving the reliability of the hatch mechanism and establish a theoretical basis for future structural optimization.