PSI - Issue 39

Hithendra Karakampalle et al. / Procedia Structural Integrity 39 (2022) 711–721 Author name / Structural Integrity Procedia 00 (2021) 000–000

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Fig. 16. Variation of SIF for all the crack combinations at 0% Interference As the crack size at location L2 increased, the percentage difference between the cases of with and without additional cracks at L1 and L3 reduced, for all crack lengths at L1 and L3. With a minor exception (in case of 2a@L2= 7 mm with 2a@L1and L3= 7 mm), for all combinations, 0.15% interference yielded the best reduction in SIF, varying from 5 % to 14%, depending on the crack length at L2. a b

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Fig. 17. Percentage difference in SIF for (a) 2a@L2=7mm ; (b) 2a@L2=9mm; (c) 2a@L2=11mm

Figures 18 and19 show the typical plots of variation of stress distribution – hoop (σ h ) and normal (σ x ), on the half circumference at L2. These plots are for the combination of 2a@ L2 = 7 mm, L1 and L3 = 0, 7, 9, 11 at 0% interference level. There is rise in stress level at L2 in presence of neighboring cracks. Higher the length of neighboring crack, greater is the increase in stress level. Either of the two - the maximum normal stress or the maximum hoop stress can be taken as a parameter for quantifying the variation in stress distribution due to the presence of neighbouring cracks.

Fig. 18. σ h for 2a@L2= 7mm and 2a@ L1 and L3= 0, 7, 9, 11 mm