Initiation of fatigue cracks

Important results from the project

The project has increased the understanding of how martensite is affected by fatigue loading before a crack occurs. The studies on how the transformation of martensite to cells of ferrite takes place has provided new insights. However, further work is needed to better understand how the degradation of martensite occurs under different stress states. The modelling has proven to be complex, several basic models have been started but much work remains to connect different modelling scales.

Expected long term effects

The increased knowledge about fatigue is an important part in the long term. Participating researchers and engineers have increased their expertise in fatigue as well as modelling, characterisation and testing. The knowledge can also be applied to other types of materials and applications. Indirectly, it also has the potential for the creation of new networks that can be used for future projects. The project has contributed to a better picture of the need for continued research in the field.

Approach and implementation

The project has included 3 technical work packages, modelling, characterisation and testing. At least 2 times a year, workshops have been carried out to jointly present and discuss the results obtained and the different deliverables between the work packages. In order to focus on the project goals, it has been important to continuously check the results and plan. Seminars have been arranged at participating companies to further spread knowledge in the respective organizations.