Generalisation of the effective notch stress concept for the fatigue assessment of arbitrary steel structures

Abstract

The paper addresses current implementations and potentials for the future in the field of fatigue assessment using local stress concepts. The background of the effective notch stress concept and its numerical application are described in detail. Common codes and regulations containing local stress approaches have been analysed and compared. A useful approach to apply the notch stress concept not only for welded, but also for unwelded steel components and machined or ground welded joints is presented. It has been shown that this approach coincides with fatigue regulations in EN 1993-1-9. Moreover, typical and innovative application areas for the effective stress concept are summarised. These comprise local weld imperfections and even for additive manufactured steel components the concept can be applied. Finally, an approach using the effective notch stress concept with random radii is presented. The relation between fatigue class and applied radius at the weld toe can be expressed by an exponential relationship.