The suspension system of external stores of a military aircraft has reached the fatigue life limit estimated during the design phase,however, some elements suggest that the duration of the structure has been largely underestimated. This work aims to re-evaluatethe fatigue life of the system and the potential extension of its use following an experimental numerical approach where, startingfrom a series of experimental flights in which the structure was instrumented, the forces acting on the system were calculated.Therefore, a methodology was developed to limit the damage calculation time using a hybrid approach that exploits the advantagesderiving from the low computational burden typical of the methods in the frequency domain coupled with the Rainflow Countingprecision. The study, although penalized by a series of conservative hypotheses, allowed to estimate a residual life equal to past life.It also provided important feedback on the field of application of advanced techniques for estimating the fatigue life of aeronauticalstructures subjected to random loading stories.
Fatigue Life Extimation of a Military Aircraft Structure subjected to Random Loads
F. Cianetti;M. Palmieri;C. Braccesi;
2018
Abstract
The suspension system of external stores of a military aircraft has reached the fatigue life limit estimated during the design phase,however, some elements suggest that the duration of the structure has been largely underestimated. This work aims to re-evaluatethe fatigue life of the system and the potential extension of its use following an experimental numerical approach where, startingfrom a series of experimental flights in which the structure was instrumented, the forces acting on the system were calculated.Therefore, a methodology was developed to limit the damage calculation time using a hybrid approach that exploits the advantagesderiving from the low computational burden typical of the methods in the frequency domain coupled with the Rainflow Countingprecision. The study, although penalized by a series of conservative hypotheses, allowed to estimate a residual life equal to past life.It also provided important feedback on the field of application of advanced techniques for estimating the fatigue life of aeronauticalstructures subjected to random loading stories.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
