Crack initiation in anisotropic wheel/rail material

Forskningsprojekt, 2021 – 2026

Rolling Contact Fatigue (RCF) crack initiation is often connected to the accumulation of plastic deformation in the surface layer of rails and wheels. The behavior and strength of this highly deformed and anisotropic layer are thus key properties of rail and wheel materials. An experimental technique to analyse and measure these properties has been developed and exploited in the CHARMEC project MU34. Here an axial-torsion testing machine is used to subject the material to loading conditions similar to RCF loading. Starting out from these experiments and numerical models developed in MU34, the current project aims to exploit and further develop fatigue crack initiation criteria for the anisotropic material. Additional experimental studies will be conducted in co-operation with the project MU35. Another important aim is to improve the modelling of the anisotropic material with respect to long-term cyclic and multiaxial loading. Throughout the project, the finite element method will be used to simulate rolling contact conditions and it will be investigated how field measurements can be used to improve and validate the modelling.