Fatigue design of cast iron components with surface discontinuities

Surface discontinuities are unavoidable properties of production castings, and have fundamental effect on in-service reliability. In the current study a multiaxial probabilistic fatigue analysis model has been developed for the description of local (e.g.: notches or surface defects) and structural gradient (e.g: bending) effects on crack initiation life. Identification of the model parameters and the validation has been done on the ferrite-pearlitic NCI grade EN GJS 500-7. The survival probability type simulation results are proven to be highly accurate with 5% average, and 11% maximum prediction error. In theory, the model might be able to assess the effect of arbitrarily complex defects on the fatigue strength, which is to be investigated in the future.