Provides methods for the assessment of fatigue resistance of members, connections and joints subjected to fatigue loading.

1. EN 1993-1-9 gives methods for the assessment of fatigue resistance of members, connections and joints subjected to fatigue loading.

2. These methods are derived from fatigue tests with large scale specimens, that include effects of geometrical and structural imperfections from material production and execution (e.g. the effects of tolerances and residual stresses from welding).

   NOTE 1 For tolerances see EN 1090. The choice of the execution standard may be given in the National Annex, until such time as EN 1090 is published.

   NOTE 2 The National Annex may give supplementary information on inspection requirements during fabrication.

3. The rules are applicable to structures where execution conforms with EN 1090.

   NOTE Where appropriate, supplementary requirements are indicated in the detail category tables.

4. The assessment methods given in this part are applicable to all grades of structural steels, stainless steels and unprotected weathering steels except where noted otherwise in the detail category tables. This part only applies to materials which conform to the toughness requirements of EN 1993-1-10.

5. Fatigue assessment methods other than the ∆σ_R-N methods as the notch strain method or fracture mechanics methods are not covered by this part.

6. Post fabrication treatments to improve the fatigue strength other than stress relief are not covered in this part.

7. The fatigue strengths given in this part apply to structures operating under normal atmospheric conditions and with sufficient corrosion protection and regular maintenance. The effect of seawater corrosion is not covered. Microstructural damage from high temperature (> 150 °C) is not covered.