A probabilistic method for multiaxial HCF based on highly loaded regions below the threshold depth

• A new HCF model based on highly loaded regions has been proposed.
• The highly loaded volume below a threshold depth yields the fatigue risk.
• Comparisons are made to the WL-model and a surface based model.
• The new model has very good transferability between geometries.
• The volume- and the gradient effects are incorporated in the new model.

For High Cycle Fatigue (HCF) assessment of structural components, a variety of evaluation methods that take important factors into account are available. The application of probabilistic evaluation methods is not always straightforward. Investigations show that the methods have limited predictive capability and most often poor transferability of fatigue test results for more complex geometries. Here, a new probabilistic HCF model based on the concept of highly loaded region is proposed. A depth parameter is taking on an important role in the proposed model. Different local stress criteria in combination with the new model and two other evaluation methods are studied. The purpose is to determine the combination of criteria and evaluation method that gives the best transferability. The results show that the new model has superior predictive capability than other models regardless the choice of fatigue stress criteria.