Research of aircraft SHP method based on changed loading spectrum

The structure of aircraft is complex, it will be affected by the aerodynamic loads and the role of maneuver overload when it was in using, thereby, it will result in a number of hidden danger relating to structural failure, and causing huge casualties and property losses at last. Therefore, this paper presents the use of time series analysis methods to dispose and analyze the load-time history data of aircraft obtained from SHM system, establishing an ARMA time series model and use this model to make a prediction of the change of the load during a certain time, then removal and re-handling the non-peak value point of the measured and predicted load-time history data, and establishing the load spectrum of the corresponding time region. Through the preparation of the changed load spectrum, using the improved rain flow counting method and linear cumulative damage criteria of Miner to estimate the key parts' fatigue life of the aircraft, finally, achieving structure health prognostic of the aircraft.