Residual Life Prediction For Aircraft Structure In Corrosive Environment With Information Updating

For the corrosion problem of aircraft structure in service of civil aviation industry,this paper explore corrosion development law of aircraft structure and research residual life prediction method and the optimal decision of maintenance, which have some practical value in safe operation, prolonging the service life and reducing the maintenance cost.Firstly, analyzing the dynamic development law of aircraft structure corrosion frequency along with detection time and age based on actual corrosion data, then principal component regression model is established for aircraft structure corrosion frequency and main meteorological environmental factors to discuss its correlation.Secondly, grey markov residual life prediction model is built for aircraft typical structure. Then residual error is used to improve the accuracy of model. And the feasibility of the prediction model is verified by numerical example, which is using the frame maintenance corrosion data.Thirdly, bayesian method is used to select the reasonable corrosion depth distribution of typical aircraft structure. Then two kinds of dynamic residual life prediction models are established based on the ideas of equal dimension grey recurrence and information updating. The numerical example results show that the reasonable distribution of frame structure corrosion depth is Logistic distribution and the updated model is more suitable for engineering practice.Finally, a mixed-integer programming(MIP) model is established to minimize the unit expected costs of maintenance under chance constraint of aircraft corrosion damage of polished tolerance. Again, the optimal time interval T* and the number N*of preventive repairs can be obtained by an improved branch and bound algorithm.The research results provide technical support for corrosion repair and maintenance of civil aircraft structure.