The topic of this masters thesis is to model the cracks and damage caused by voids created in creep and fatigue damage operations focusing on creep resistant martensitic steels such as P91, P92 and X20. This will be done by:
- Setting up micro structural models for damage evolution during creeps fatigue.
- Modelling the formation of creep voids under consideration of the local microstructure, eg local effective diffusion of vacancies.
- Local evolution of dislocation structures due to stress concentrations.
- The model does not have to be spatially resolved, but by a statistical representation of the microstructure.
- Then linking creep formation to crack initiation.
- Model crack propagation and coalescence on a mesoscopical level where unstable crack growth finally links to component failure.