For predicting the fatigue lifetime of a P/M component not only the loading history must be considered, but also the porosity distribution, which can influence the material behaviour significantly and which is calculated in the first step of the simulation. A model developed for describing the fatigue damage evolution in fully dense steels was adapted to the special situation in P/M materials. On the basis of elastic-plastic fracture mechanics a damage parameter is developed and the number of cycles to failure is linked to the damage parameter by a power -law relation.
