Issue 9

C. M. Sonsino, Frattura ed Integrità Strutturale, 9 (2009) 3-12; DOI: 10.3221/IGF-ESIS.09.01 4 Figure 2 : Reliability and safety aspects in fatigue design. Figure 3 : Offshore wind power plant (REpower Systems AG). Figure 4 : Offshore oil platform. Figure 5 : Overview of fatigue design concepts for welded joints. As for the fatigue critical areas of the K-nodes, Fig. 6, at the chord-sided weld seam a nominal stress cannot be defined and as the notch strain concept is not yet sufficiently mature for application, only the hot-spot stress concept, the notch stress concept and the crack propagation concept will be compared, based on experimental results obtained with gas metal arc welded K-nodes, Fig. 6, from the fine grained structural steel Fe 355 [3] . The tests were carried out under constant and variable amplitude loading under artificial sea-water. The straight line spectrum for variable amplitude loading (Common