Method for determining fatigue load of refitted part of aircraft fuselage

Abstract

The invention relates to a method for determining a fatigue load of a refitted part of an aircraft fuselage, which comprises the following steps: obtaining actual measurement strain data of the part through flight actual measurement by knowing original design parameters and refitted structure parameters of the aircraft fuselage and knowing historical flight parameter data after the aircraft is refitted; acquiring flight parameter data in flight actual measurement through a flight parameter recorder; subjecting the two types of data to correspondence in the time and frequency relation, and forming fatigue load actual measurement data of the fuselage refitted part; carrying out correlation analysis on the average strain data of the refitted part and the flight parameter of the aircraft to obtain a relationship between the average strain data of the refitted part of the aircraft and the flight parameter data of the aircraft; calculating average strain data of an extended refitted part by applying historical flight parameter data after the airplane is refitted, combining the historical flight parameter data after the airplane is refitted and fatigue load measured data of a fuselage refitted part to form fatigue load data of the refitted part, and forming a strain accumulation transcendental curve or a parameter accumulation transcendental curve, which can be spectrally compiled, via data processing.

Description

technical field [0001] The invention belongs to the technical field of aircraft fatigue tests, and relates to a method for determining the fatigue load of aircraft fuselage modification parts. Background technique [0002] The fuselage structure is the main loading part of the aircraft. During the design of the aircraft, the layout design was carried out according to the requirements of the aircraft. Refitting will inevitably lead to changes in the fatigue load of the aircraft fuselage structure, which will change the service life of this part and affect the flight safety of the aircraft. Therefore, life assessment after modification must be carried out. [0003] As the basis of the fatigue load spectrum, the fatigue load is the design input for the structural life assessment. The biggest difficulty in the life assessment of the aircraft fuselage modified structure is to obtain the fatigue load. The accuracy of the fatigue load directly affects the reliability of the life re...

AI Technical Summary

Problems solved by technology

[0004] Fatigue load measurement is a common method to determine the fatigue load of aircraft fuselage modification parts. The advantage of this method is that the load history actually occurs. The disadvantage is that the load measurement work is limited by factors such as time and manpower. It can only be used in combination with the actual use of the aircraft. Obtaining a limited number of flight parameter data and local strain data, the sample size is seriously insufficient, and cannot effectively reflect the dispersion of fatigue loads, which seriously affects the reliability of load data and the credibility of life assessment conclusions

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