5. Conclusion

This note describes the various methods of calculating damage available either in operator POST_FATIGUE or in operator CALC_FATIGUE, or in both commands simultaneously.

These methods can be classified into two main classes:

• estimation of damage at large numbers of cycles,

• estimation of damage in oligocyclic plastic fatigue.

In the first class of problems, we find the Wöhler method, which is based on uniaxial tests, and which applies to stress loads. Also included in this class are the Crossland criterion, which is an empirical criterion based on macroscopic quantities, and the Dang Van Papadopoulos criterion, which is based on microscopic phenomena.

Both criteria are aimed at stress loads that may be uniaxial or multiaxial but periodic.

In the second class of problems, we find the Manson-Coffin method and the Taheri methods, which apply to deformation loads.

All methods based on uniaxial tests (Wöhler method, Manson-Coffin method and Taheri methods) are available in the two operators POST_FATIGUE and CALC_FATIGUE.

The criteria, on the other hand, are only available in POST_FATIGUE.