Nominal stress concept
The nominal stress concept ( english stress concept in nominal terms ) is in the engineering mechanics a computational method for evaluating the fatigue strength of non- welded and welded components.
The nominal mechanical stresses required for this concept are related to a defined cross-section and can generally only be used for simple rod-shaped and sheet-like components, whereby stress concentrations such as size and notch influences are not taken into account. Therefore, these influences must be taken into account by means of correction factors , the so-called shape and notch action numbers.
The fatigue strength analysis not welded components is effected by the application of Formzahl- SN curves , in which the notch to be considered cases or geometric discontinuities are included. In the case of welded components, the welded connection made is compared with a construction detail (classified seam courses on structures) that corresponds to a notch or fatigue strength class, the so-called FAT class. A Wöhler curve is stored for each FAT class, which is compared with the effective voltage range .
Individual evidence
- ^ E. Haibach: Fatigue strength - method and data for component calculation , Springer Verlag, 2006
- ↑ K.-H. Grote, J. Feldhusen: Dubbel - paperback for mechanical engineering , Springer Verlag, 2007
- ↑ Construction standards committee: DIN EN 1993-1-9 Eurocode 3: Dimensioning and construction of steel structures - Part 1-9: Fatigue , DIN German Institute for Standardization eV, 12.2010