For the design of safety-critical components, a reliable fatigue strength assessment is indispensable. Since experimental investigations require significant financial resources, purely computational approaches are highly important, especially for small and medium-sized enterprises. However, established design guidelines, such as the “FKM Guideline Nonlinear”, do not permit the consideration of damage-relevant defects, which have a strong influence on the fatigue strength of components made of defect-containing materials, such as cast aluminium alloys and high-strength steels. This leads to relatively high safety factors and strict requirements regarding the material purity or the maximum pore size for these components, resulting in high scrap rates.

On this background, our research project aims to extend the “FKM Guideline Nonlinear” for a systematic consideration of defects and their impact on the fatigue strength. To develop a respective assessment concept a sufficient database is required, which will be established through comprehensive literature studies and targeted experimental investigations. In addition to defect size and defect density, we will also consider the sensitivity of the material volume to defects (defect tolerance). Finally, we will validate the concept with component tests and implement it in practical tools for industrial design approaches.