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 wing panels during full-scale bench tests and in the brackets of the in-service airframe was estimated by measuring the spacing of meso-beach-marks (MBM) and fatigue striations. The 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.

中文翻译：

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RRJ-95 飞机结构部件在役损伤容限原则的基础

研究了 RRJ-95 飞机框架的几个区域和结构部件中的孔引起的疲劳裂纹。使用定量断口法，通过测量细观海滩标记 (MBM) 和疲劳条纹的间距，估算了全尺寸台架试验期间机翼面板和在役机身支架中的裂纹扩展持续时间。台架试验的应用程序由相当于飞行中翼载荷的可变载荷块组成，并再现了示意性的飞行周期。结果表明，RRJ-95 飞机框架的几个结构部件中疲劳裂纹扩展的持续时间与裂纹成核持续时间大致相同。