1.1 Scope of EN 1993-1-9
(1) EN 1993-1-9 gives design methods for the verification of the fatigue design situation of steel structures.
NOTE Steel structures consist of members and their joints. Each member and joint can be represented as a constructional detail or as several of the latter.
(2) Design methods other than the stress-based methods, such as the notch strain method or fracture mechanics methods, are not covered by EN 1993-1-9.
(3) EN 1993-1-9 only applies to structures made of all grades of structural steels and products within the scope of EN 1993-1 (all parts), in accordance with the provisions noted in the detail category tables or annexes.
(4) EN 1993-1-9 only applies to structures where execution conforms to EN 1090-2.
NOTE Supplementary execution requirements are indicated in the detail category tables.
(5) EN 1993-1-9 applies to structures operating under normal atmospheric conditions and with sufficient corrosion protection and regular maintenance. The effect of seawater corrosion is not covered.
(6) EN 1993-1-9 applies to structures with hot dip galvanizing in accordance with the provisions noted in the detail category tables or annexes.
(7) Microstructural damage from high temperature (> 150°C) that occurs during the design service life is not covered.
(8) EN 1993-1-9 gives guidance of how to consider post-fabrication treatments that are intended to improve the fatigue resistance of constructional details.
1.2 Assumptions
(1) Unless specifically stated, EN 1990, EN 1991 (all parts) and EN 1993 1 (all parts) apply.
(2) The design methods given in EN 1993-1-9 are applicable if:
- the execution quality is as specified in EN 1090-2, and
- the construction materials and products used are as specified in the relevant parts on EN 1993 (all parts), or in the relevant material and product specifications.
(3) The design methods of EN 1993-1-9 are generally derived from fatigue tests on constructional details 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).