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Figure Captions
Fig. 1. The fractured bracket (inside the circle) on the RRJ-95 aircraft (No. 89051) (a) and fracture surfaces by the four lug sections (b).
Fig. 2. Microstructure of investigated aluminum alloys: 1933T3 (a) and 1163 (b).
Fig. 3. The crack (inside the circle) propagated to the face plane of the stiffened panel from under the middle bracket of the engine pylon mount in the RRJ-95 aircraft (No. 95075) and the scheme of the airframe with the area of bracket position (view A).
Fig. 4. Initial fracture zones in bracket lug sections No. 1 (a), 2 (b), 3 (c), and 4 (d) of the engine pylon mount in the RRJ-95 aircraft (No. 95075) with origins indicated by the arrows.
Fig. 5. The blocks of MBM (a) and fatigue striations (b) on the fracture surfaces No. 1 and No. 4 of the RRJ-95 aircraft (No. 89051) lug, respectively.
Fig. 6. The plot of the MBM spacing “h ” (lug section No. 1) and the fatigue striation spacing “δ” (lug sections No. 2-4) versus the crack length “a ” of the RRJ-95 aircraft (No. 89051).
Fig. 7. The plot of crack growth duration in terms of the number of blocks “n f” (lug section No. 1) and the number of unit cycles “N f” (lug sections No. 2-4) versus the crack length “a ” of the RRJ-95 aircraft (No. 89051).
Fig. 8. The fracture surfaces No. 1-4 in the RRJ-95 aircraft (No. 95075) wing panel.
Fig. 9. The fatigue MBM blocks on the fracture surfaces No. 2 (a) and No. 3 (b) at different crack length for the RRJ-95 aircraft (No. 95075).
Fig. 10. The plot of the MBM spacing “h ” and the number of blocks “n f” versus the crack length “a ” for fracture surfaces No. 2 (a) and No. 4(b) of the RRJ-95 aircraft (No. 95075).
Fig. 11. The program of bench-test loading along the OY (a) and OZ (b) axes for the lower panel of the RRJ-95 aircraft (No. 4862) wing reproducing single schematized flight loading cycle.
Fig. 12. Fracture surfaces in the lower panel of the RRJ-95 aircraft (No. 4862) wing.
Fig. 13. The MBM reflecting the block loading of the lower panel of the RRJ-95 aircraft (No. 4862) wing in accordance with the schematized flight cycle (a), and the plot of the MBM spacing “h ” and the number of blocks “n f” versus the crack length “a ” in the panel (b).
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