PSI - Issue 57

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Francis Blanc et al. / Procedia Structural Integrity 57 (2024) 343–354 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

Figure 11: View of degraded areas between the filaments

7. Conclusions

The tests carried out have enabled us to plot and compare several Lf curves. If we compare the number of cycles to failure for BASQUIN curves, we see that the lifetime strongly depends on / ratios. The ratio / = 33 makes it possible to obtain longer service lives than the ratio / = 25 and significantly longer than the ratio / = 12.5 for the same safety factor Sf. By comparing the curves, it seems that the Life factor theory works very well for the 150 with the ratios / = 33.3 and / = 25.0 on the condition of comparing only the point that we have obtained at 50%, assuming that the shape of the curves is the same. For the 75 , 100 and 200 curves, there are differences of around 10%: - 10% more for the ratio / = 33.3 , - 10% less for the ratio / = 12.5 . The various fatigue curves clearly show the significant decrease of residual tensile strength according to the number of bending fatigue cycles. These cures make it possible to have a better knowledge of the allowable load in fatigue. We can see that the applied force is high (low value of Life factor), the drop in residual tensile strength is less significant but the number of cycles achievable is also lower.

8. Future work and perspectives

The next step is to compare these results for one rope technology and material with others. Tests are in progress with HMPE fibers. 9. Acknowledgements This work was carried out in the large project of the winch of the future for lifting companies, of which other studies are taking place in parallel such as optimization studies of hybrid winches, research into new non -destructive