Tito Andriollo¹, Yubin Zhang¹, Søren Fæster¹, Jesper Hattel¹, Varvara Kouznetsova²; ¹Technical University of Denmark, ²Eindhoven University of Technology

Accurate prediction of the fatigue properties of ductile cast iron components is crucial in sectors like transport and energy production. So far, mainly empirical methods have been used to correlate the primary microstructural parameters, i.e. size and distribution of the graphite particles, to the crack nucleation and growth rate under cyclic loading. To attempt a micro-mechanical interpretation, a 3D finite element model of the region surrounding the crack tip in a compact tension specimen is created. The model consists of an internal region where the microstructure reconstructed with computed tomography – matrix plus graphite particles – is discretized and a homogenized external region where displacement boundary conditions measured via digital image correlation are applied. The results reveal the existence of a correlation between the crack nucleation site and the plastic strain accumulated during each cycle. In addition, a weaker correlation between crack propagation direction and maximum principal stress is found.