PSI - Issue 5

Slobodanka Boljanović et al. / Procedia Structural Integrity 5 (2017) 801 – 808 Slobodanka Boljanović, Stevan Maksimović / Structural Integrity Procedia 00 (2017) 000–000

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Fig. 4. Crack length against number of loading cycles to failure for the lug with through-the-thickness crack ( R = 0.1): (a) w = 85.7 mm (Experiment 1 – ABPL48, Experiment 2 – ABPL92); (b) w = 85.7 mm (Experiment 1 – ABPL46, Experiment 2 – ABPL93). Experimental results are reported by Kathiresan and Brussat (1984). 4.3. The effect of height of the lug head and thickness on the fatigue failure behavior of damaged lug Finally, for the fatigue critical wing-fuselage attachment lug, the effect of height of the lug head and thickness on the residual life is analyzed. In the fatigue calculations, the following cyclic loading conditions and geometries of the lug are examined: (a) P max = 48000 N, R = 0.5, D = 36 mm, t = 14 mm and two different width-diameter ratios w / D together with four corresponding heights of the lug head H i.e. (2.00, 36 mm; 2.00, 50.4 mm; 2.25, 40.5 mm; 2.25, 54.7 mm), respectively, and (b) P max = 52000 N, R = 0.5, w = 90 mm, D = 40 mm, H = 45 mm and three different thicknesses t (12 mm, 15 mm, 18 mm). For considered lugs with an initial through-the-thickness crack ( a 0 = 2 mm) at a hole, made of 7075 T651 alloy, the same material parameters are assumed as mentioned in Section 4.2.

Fig. 5. Crack length against number of loading cycles to failure for the lug with through-the-thickness crack: (a) 1 – w / D = 2.00, H = 36 mm, 2 – w / D = 2.00, H = 50.4 mm, 3 – w / D = 2.25, H = 40.5 mm, 4 – w / D = 2.25, H = 54.7 mm; (b) 1 – t = 12 mm, 2 – t = 15 mm, 3 – t = 18 mm.