PSI - Issue 75

7

Fabrice Deleau et al. / Procedia Structural Integrity 75 (2025) 392–418 Emmanuel Persent, Deleau Fabrice, Guillaume Coudouel, Guillaume Perrin/ Structural Integrity Procedia (2025)

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Fig.6: Hydrostatic stress at maximum load (a) and minimum load (b).

The highest normal stress on all planes is defined as the first principal stress I  , the stress level at the two key instants is shown in Fig. 7, and its values are shown to be consistently positive in the grooves of the connector, thus the highest normal stress is tensional during the cycle. Moreover, this magnitude is greater at maximum load than at minimum load.

Fig. 7: First principal stress at maximum load (a) and minimum load (b).

One way to classify the stress state is through the stress triaxiality factor, defined as . The distribution of the triaxiality factor at the maximum load is shown in Fig. 8. We can see that, inside the lug grooves of the connector, 0 .6 7 0 .    , so the stress state is close to an equi-bitension case (i.e. 0.66   ). VM H    =