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. 9. SIF at 0.15 % interference level

Fig. 10. SIF at 0.3 % interference level

The percentage change in SIF at the crack tips w.r.t 0% interference are shown in the Fig. 11-12. The previous studies on interference at joints, showed that interference up to certain levels produced reduction in SIF at all crack lengths [Prakash and Hithendra (2020)] and improved fatigue lives [Lanciotti and Polese (2005), Chakherlou et al. (2010), Ying et al (2016), Sabbaghi et al. (2018)]. Even in this study, interference proved to reduce the SIF up to some extent, but the extent of reduction in SIF overlapped for different interference levels at different crack lengths owing to the presence of joints in the path of the crack. Considering both the crack tips, the most beneficial interference level was found to be 0.15%, with up to 11.46% reduction in SIF, with the maximum reduction occurring at a crack length of 8 mm.

Fig. 11. Percentage change in SIF at crack tip 1 w.r.t zero interference

Fig. 12. Percentage change in SIF at crack tip 2 w.r.t zero interference

3.2. Case 2: SIF values during the crack propagation from joint L2, symmetrically towards joints L1 and L3 are plotted in Fig.13 at various interference levels and the corresponding percentage change in the SIF is shown in the Fig. 14. For crack lengths till a crack length of 11 mm, interference of 0.1% reduced the SIF the most (~20%). Beyond this crack length, the reduction in SIFs seems to be the similar (5-10%) for all the interferences values, except in case of 0.3%.