PSI - Issue 71

Akash Shit et al. / Procedia Structural Integrity 71 (2025) 50–57

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a

b

Fig. 6. H4 and H5 under 0% interference (a) Variation of SIF with crack length (b) % change in SIF w.r.t the plane’s perpend icular crack propagation

At all the locations, irrespective of the level of interference, mixed mode fracture behavior was observed for the initial 6 mm crack; due to that, a peak value of percentage difference of stress intensity factor was observed at this crack length. After that, mode-I SIF was found to dominate over mode-II SIF. At hole 4, the percentage difference of SIF increases with crack length, and a maximum of 7% less SIF is observed at 2a=12mm crack length than in the case of plane perpendicular crack propagation, shown in Fig. 6(b). Whereas for hole-5, the percentage difference of SIF decreases with crack length, and a maximum of 13% more SIF is observed for 8 mm crack length than the plane perpendicular crack propagation. 3.2. Impact of MERR-Based Crack Advancement on SIF With 0.1% and 0.15% Interference The difference in SIF is also calculated with the two most beneficial interference levels, 0.1% and 0.15% [Hithendra and Prakash, (2021)]. Here also, the maximum percentage difference for the initial 6 mm crack length is observed, and the SIF obtained is less than 78% and 80% for hole 4 and hole 5, respectively, due to mixed mode fracture, as discussed in the earlier section. a b

Fig. 7. H4 and 5 under 0.1% interference (a) Variation of SIF with crack length (b) % change in SIF w.r.t. the plane’s perpen dicular crack propagation a b

Fig. 8. H4 and H5 under 0.15% interference (a) Variation of SIF with crack length (b) % change w.r.t. the plane’s perpendicu lar crack propagation

Fig. 7 shows that at 0.1% interference for hole 4, the percentage difference in SIF is less between MERR-based crack propagation and plane perpendicular crack advancement. Nevertheless, at hole 5 for 7 mm crack length, 23% more SIF was observed in the MERR case.