Simulation of microstructurally controlled short crack propagation

A model for the simulation of stage I fatigue crack propagation is presented. The model considers the barrier effect of grain boundaries and phase boundaries on short crack propagation rate and the crack path deflection due to the microstructure. The plastic zones in front of the crack tip are modelled as yield strips. The mechanical boundary value problem is solved numerically by a boundary element method. The method was applied based on a statistical model of duplex microstructures, generated by a special Voronoi-algorithm, so that the influence of the distribution of phases on crack propagation can be analysed.