基于马尔可夫链的飞机结构腐蚀状态预测

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

腐蚀损伤是最常见的飞机结构损伤形式之一,会降低结构的剩余强度和耐久性。针对在役民用典型机型飞机易腐蚀结构,首先将腐蚀状态划分为5个等级;其次拟合遭受腐蚀的飞机结构剩余厚度递减函数,给出腐蚀状态转移概率矩阵,建立马尔可夫状态预测模型。最后收集某型飞机后货舱隔框腐蚀数据作为算例,预测了隔框结构在潜伏期之后的腐蚀状态。结果发现使用26个月之后,沿海地区飞机隔框结构腐蚀已达到三级状态。预测结果与工程实践相符,说明马尔可夫模型适用于飞机结构腐蚀状态预测。

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.