Research On Health Monitoring And Maintenance Strategy For Civil Airplane Flap Mechanism

Though China civil aviation industry is developing rapidly,the whole aviation industry,especially the aviation maintenance industry,is sustained by shortage of modern maintenance capacity.In the modern enterprise,the problem of over-maintenance or lack of maintenance is more serious.Therefore the development of civil aviation maintenance industry needs to catch up with the development of the whole industry.Along with the development of modern maintenance theory,the current maintenance methods are often combined with Hard Time Maintename,Condition Based Maintenance and Condition Monitoring,the using of advanced detection technology and maintenance strategy,to optimize the maintenance interval,reduce the maintenance and repair costs.In this paper,the national and long-term scientific and technological development plan is guided.The reliability of aircraft system,components,safety and availability requirements are meted,by discussing the real-time monitoring of the aircraft damage flap parts surface by advanced technology,combination of the test and simulation of civil aircraft flap components,application of advanced detecting technology in civil aviation maintenance industry.In this paper the following aspects are included:1.Construction of bench test machine,carrying out the rail wear performance test bench,rail life stress life data analysis is discussed.And the surface morphology of typical specimen were analyzed,the specific rolling roller slide friction and wear process of the edge stress concentration and coating plastic deformation until the peeling phenomenon and analyzes the causes.2.Introduction of the reliability coefficient of two parameter basing on Weibull distribution,and distribution of the fatigue life and reliability of a certain degree of confidence and calculating the fatigue life dispersion coefficient,and the safety life of civil aircraft structures are studied.Through the three parameters of density function,least squares curve fitting of the life and the theory of fracture mechanics method,with comparing the two kinds of life prediction model,are all studied.3.In the actual engineering process,the influence of various factors to the fatigue life will bring uncertainty.In order to be reflected in the life distribution,Weibull distribution is introduced to study the fatigue life reliability of flap under the same stress level.And the components of the flap preventive maintenance strategy and model maintenance interval optimization model and the structural fatigue damage of the maintenance tasks are studied.4.A metal contact damage model based on a single sensor is established,and the parameters of the sensor are optimized based on the sensitivity index and the finite element simulation analysis.The experimental study is carried out to analyze the typical damage signal.Basing on the multi static sensor,the static induction model and the wavelet single branch reconstruction signal processing method are introduced.5.The electric charge tomography algorithm to realize the on-line monitoring of the array type electrostatic sensor is introduced,including: linear back projection algorithm(LBP),regularization algorithm,based on multiple linear regression(MLRR)algorithm,and so on.Two criteria are introduced:(1)the relative image error;(2)the correlation coefficient between the reconstructed image and the original image,and the simulation of several typical damage charged conditions are made,and can be evaluated.6.Metal contact electrostatic signal is diagnosed in public factors and image index as a covariate,the proportional hazard(PH)model to describe the failure probability of the flap mechanism,such as reliability and lifetime.Based on the fuzzy theory,the optimal algorithm of the maintenance cycle is given,and the algorithm is applied to the engineering practice.7.On the basis of the roller and rail force mechanism analysis,the probability function and the limit state function are proposed.Baseing on the linear approximation,the failure probability and reliability sensitivity are researched in linear hypothesis and nonlinear hypothesis.During the opening process of flap mechanism,the mean deviation of the angular velocity rotation of the flap mechanism has the largest affection on mechanis.8.Evaluation of the mechanism reliability is got by using the online monitoring mechanism sensor.The study of maintenance interval decision model in practice is made under the constraint of failure probability in maintenance cycle.