Issue 38

E. Shams et alii, Frattura ed Integrità Strutturale, 38 (2016) 114-120; DOI: 10.3221/IGF-ESIS.38.15 119 Results To standardise the S - N curves belonging to different load ratios, the influence of the mean stresses was considered through the fatigue enhancement factor f ( R ) according to IIW recommendations [13]. The fatigue lives of all tested loading configurations are related to the standardised stress values in Fig. 7. The failure criterion is the specimen rupture. Regression analysis leads to the life curve (solid line in Fig. 7), having a slope of k = 3.0 and a scatter value of T  = 1:2.0. The scatter band for 10% and 90% probabilities of survival is illustrated with dashed curves. Figure 7 : Standardised S - N curve. C ONCLUSIONS general approach for the fatigue assessment of weld ends under multiaxial loading has been developed. Notch stresses have been calculated based on an idealised weld end model including different radii for weld root and toe. The final result is a S - N curve for the determination of fatigue life of weld ends under multiaxial loading conditions. A CKNOWLEDGEMENTS he authors gratefully acknowledge the financial support of the research Project A 288 by the “Research Association for the Iron and Metalworking Industry e. V.” and the “Foundation Research on Steel Application”. Technical support during the project was given by the Research Association of Automotive Technology FAT. The specimens were provided by “Benteler Automobiltechnik GmbH” and the support is highly appreciated. R EFERENCES [1] Kaffenberger, M., Vormwald, M., Application of the notch stress concept to the real geometry of weld end points, Mat.-wiss. u. Werkstofftech., 42 (2011) 289-297. [2] Kaffenberger, M., Vormwald, M., Fatigue resistance of weld ends - Analysis of the notch stress using real geometry, Mat.-wiss. u. Werkstofftech., 42 (2011) 874-880. [3] Kaffenberger, M., Malikoutsakis, M., Savaidis, G., Vormwald, M., Fatigue resistance of weld ends, Comput. Mater. Sci., 52 (2012) 287-292. [4] Kaffenberger, M., Vormwald, M., Considering size effects in the notch stress concept for fatigue assessment of welded joints, Comput. Mater. Sci., 64 (2012) 71-78. A T