Study On The Environmental Deterioration Inspection Intervals Of Aircraft Structure Based On The FAHP

Aircraft structural maintenance program is an important part of the maintenance program. Developing structural maintenance program should follow the MSG-3 maintenance concept, and then effective maintenance intervals and maintenance tasks are developed to ensure the aircraft inherent safety and reliability. Determining inspection interval of environmental deterioration(ED) is an important part of developing structural maintenance program.Firstly, the principles which include ED for aircraft structures are analyzed. Then the general methods for determining structural maintenance intervals are introduced and a detailed analysis of the matrix method for Boeing and Airbus is studied. Given that rating of ED is a complex process involving a number of factors that have the ambiguity, a combined evaluation model based on fuzzy mathematics and analytic hierarchy process is proposed, namely fuzzy hierarchy comprehensive model of aircraft structural environmental deterioration. Both fuzzy comprehensive evaluation method and the rough set information entropy theory which can be used to calculate the significance of attribute are used in the modeling process. Then the weight set can be calculated through the fuzzy judgment matrix constructed by using significance obtained. After that total rating of ED is calculated according to which the maintenance interval is determined. Then the structural significant items of a certain type aircraft are taken as examples to verify the method. On this basis, ED analysis software is designed and developed.Fuzzy hierarchy comprehensive evaluation model of ED proposed turns out to be effective. Nowadays a civilian aircraft with independent intellectual property rights is being developed in our country, so studying in this paper can be a reference for the engineering to determine maintenance interval and develop maintenance program.