5. Conclusion

The aim of this article was to complete the field of fatigue with a large number of cycles [M 4 170] , and in particular to :

• detail the field of fatigue crack propagation for parts in service where flaws are the source of cracking under cyclic loading, and for which it is necessary to monitor crack evolution or accurately determine residual service life. The crack propagation test has been described in detail, enabling us to identify the main material parameters relating to propagation speed, C and m associated with the Paris law, as well as the propagation threshold ΔK _threshold below which propagation no longer occurs. Recommendations were given (choice of specimens, pre-cracking, methods for measuring crack growth)...