X-ray micro-tomography coupled to the extended finite element method to investigate microstructurally short fatigue cracks

In this paper we will,present how it is possible to couple a 3D experimental technique with a 3D numerical method in order to calculate the stress intensity factors along the crack front taking into account the real shape of the crack. This approach is used to characterize microstructurally short fatigue cracks that exhibit a rather complicated 3D shape. The values of the stress intensity factors are calculated along the crack front at different stages of crack propagation and it can be seen that the crack shape irregularities introduce rather important fluctuations of the values of K-I, K-II, and K-III along the crack front., The values of K-I obtained taking into account the real shape of the crack are significantly different from the ones calculated using an approach based on a shape assumption