Estimating fatigue limit distributions under inhomogeneous stress conditions

A model for calculating the fatigue limit distribution based on the inclusion size is presented in this paper. The model uses the areamax-model as a relation between the inclusion sizes and the fatigue limit and assuming that the inclusion size above a fixed threshold follows a Generalized Pareto distribution. The stress is considered to be inhomogeneous in the component. The data that is used is from two different fatigue tests, rotating bending and uniaxial test. The fatigue limit is compared for these two tests and for two different components. Confidence intervals for the fatigue limit distribution, inclusion size and the inclusion intensity are calculated.