Discussion on the Hot-Spot and Notch Stress Based Fatigue Assessment Methods Based on Test Results

The focus of the current paper is the investigation of different local stress calculation methods for fatigue design. To evaluate the accuracy and applicability of the hot-spot and effective notch stress (ENS) fatigue assessment methods an experimental and numerical research program is carried out at the BME Department of Structural Engineering, in Hungary. Two types of structural details are tested using 32 test specimens, a cruciform and a gusset plate type joint. The test results and the accompanying numerical calculation results are statistically evaluated and compared. Analysing the results of the fatigue tests and numerical calculations, it is concluded, that both the hot-spot and the ENS method could be used for fatigue design of the cruciform joints according to the recommendation of the IIW (Hobbacher in Recommendations for fatigue design, Springer, Paris, 2004). However, the rules of the ENS method needs improvement, if used for the design of gusset plate type joint. According to the current results, the ENS method can be adjusted to make applicable for the gusset plate joints as well, recommendation for that is presented in the current paper.