Issue 45

L.M. Viespoli et alii, Frattura ed Integrità Strutturale, 45 (2018) 121-134; DOI: 10.3221/IGF-ESIS.45.10 131 Load Nominal Stress Weld Toe SED Expected Fatigue Life in Cycles, Probability of Failure Specimen N° Cycles at Failure kN MPa Nmm mm 3 2.3 % 50 % 97.3 % 75 160 0.239088 238966 582073 1439280 1 235053 2 295488 65 140 0.183052 356706 868865 2148425 3 493451 4 369923 85 180 0.302596 167833 408808 1010851 5 154924 6 189280 Table 5 : Summary of the experimental results and the predicted fatigue life according to the Mean Strain Energy Density method. All the tests have been performed at a load ratio R=0. T EST RESULTS AND COMPARISON WITH PREDICTIONS o verify the fitness of the models adopted to predict the fatigue life behavior of the joint, a series of tests have been executed. All the tests have been carried over on a 100 kN Instron hydraulic traction machine at the frequency of 10 Hz. The load ratio adopted is R=0, then the load amplitude corresponds to the maximum load. A total of six specimens have been realized and tested, two specimens for three load levels, as specified in Tab. 5. In the same table, are summarized also the expected fatigue lives of the specimens according to the fatigue band in Fig. 3 and the effective life of each specimen. The specimens have been realized welding plates of S355 structural steel with MIG process, using ESAB OK AUTROD 12.51 copper coated wire as filling material and tested as welded. Figure 4 : Overview of the fatigue life predictions for the different techniques adopted and the experimental results. T