Foundation of damage tolerance principles in-service for the RRJ-95 aircraft structural components
A.A. Shanyavskiy1), 2) *, A.P. Soldatenkov1), A.A. Toushentsov1)
1) Aviation Register for the Russian Federation, Airport Sheremetievo-1, PO Box 54, Moscow region, Chimkinskiy State, 141426, Russia
2) Institute of Computer Aided Design, 2nd Brestskaya street 19/18, Moscow, 123056, Russia
Abstract. Fatigue cracks initiated from holes in several zones and structural components of the RRJ-95 aircraft frames were investigated. Using the method of quantitative fractography the crack growth duration in the brackets of the in-service airframe and in the wing panels during full-scale bench tests was estimated the spacing of meso-beach-marks (MBM) and fatigue striations. Applied program of bench test consisted of blocks of variable loads that were equivalent to the wing loading in flight and reproducing schematized flight-cycle. It was shown that the duration of fatigue crack propagation in several structural components of the RRJ-95 aircraft frames was approximately the same as for the crack nucleation duration. The total lifetime is sufficiently long for cracks in the structural components to be detected and reliably monitored with a large operating time interval between adjacent inspections.
Keywords : aircraft components, in-service fatigue, variable amplitude loading, quantitative fractography, crack growth duration, number of flights