Application of Markov Chain to Prediction of Corrosion Conditions for Aircraft Structures

The corrosion damage is one of the most common injuries in aircraft structures, which reduces the residual strength and durability of aircraft structures. Therefore, this study focused on the prediction of corrosion states of a typical civil aircraft structure based on Markov theory. Firstly, the corrosion states were divided into five levels. Secondly, the decreasing function of remaining thickness of corroded structures were fitted. The corrosion state transition probability matrix was calculated, and the corrosion depth of Markov predictive models was given. The corrosion states of aft cargo frame in the typical civil aircraft were adopted in the example. The corrosion state of the frame at the time after incubation period was predicted, and the result indicated that the frame corroded into the most serious state at coastal site after 26 months. The prediction of Markov model is conformed to the engineering practice, indicating that Markov model is applicable to the prediction of aircraft structural corrosion state.