Derivation of synthetic Wöhler lines for iron casting materials

  Graphical issue SWL Eisenguss Copyright: © IWM


Christoph Ripplinger © Copyright: IWM


Christoph Ripplinger

Research group Fatigue and Fracture Mechanics


+49 241 80 99535




For optimal material utilization, raw materials and energy conservation, an optimal component utilization has to be achieved.

In order to meet the requirements, the step of optimum material utilization must be made possible at the design stage. Computational design concepts based on material guide lines (local stress concept) and component guide lines (nominal stress concept) are used for this purpose. In order to be able to assess the stress resistance of cast iron components with spheroidal graphite (GJS), synthetic Wöhler S-N lines (SWL) are used in addition to material standards and guidelines.

It has been found that the existing guidelines and standards do not meet the new GJS materials and that there are clear differences between experimental and calculated stresses.

The research project "SWL - Eisenguss" produces results that are highly relevant for the fields of energy technology, vehicle technologies and manufacturing technologies.

Results are to be generated that allow fast and reliable component design and lightweight construction, thus reducing costs and resources. From these results, a synthetic Wöhler lines concept is to be developed, which allows a reliable estimation of the fatigue behavior of spheroidal cast iron under cyclic loading with varying influences (temperature, notch effect, and microstructure).

The determination of SWL allows a life expectancy of the components without life tests using strength static data sets.

Construction components can be designed and optimized against fatigue using the synthetic Wöhler guidelines for GJS materials. This leads to increased resource efficiency.

Small medium-sized entrepreneurs (kmU) have the opportunity to react flexibly and quickly to new material developments.


  • Development of a design concept based on synthetic Wöhler lines for thin- and thick-walled cast components made of ductile cast iron (GJS)
  • Sustainable development on the unused material potential of cast irin with spheroidal graphite (GJS)
  • Statically assured estimation of material fatigue resistance and component life
  • Increased competetiveness of small and medium-sized enterprises (kmU)
  • Cotribution to the development of standards and guidelines

Project Contents

  • Characterization of the quasi-static, cyclic and component-bound material behaviour
  • Investigation of the influence of the mean stress, temperature, notch effect as well as aried microstructures on the material loadability
  • Types of stress: Axial loading, torsion, bending, internal pressure
  • Materials: EN-GJS-400-18U-LT, EN-GJS-450-18, EN-GJS-600-10, EN-GJS-700-2


Aerodyn, Ari Automotives, Georg Fischer AG, Heger Guss, nCode, Senvion, IHI, Magma, Siempelkamp, MAN, Knorr-Bremse, AVL, Friedrich Wilhelms-Hütte, Rheinmetall Automotive, Frankenguss, twin, ThyssenKrupp, ZF, Enercon, iGF, Fraunhofer LBF, MFPA Weimar,



IGF-Grant number: 19257 BG