Fatigue crack propagation: In situ visualization using X-ray microtomography and 3D simulation using the extended finite element method

By E. Ferrié, J. Buffière, W. Ludwig, Anthony Gravouil, L. Edwards. 2006

139 citations recorded by the source corpus.

The propagation of a semi-elliptical crack in the bulk of an ultrafine-grained Al-Li alloy has been investigated using synchrotron radiation X-ray microtomography. In this material, the studied crack, despite its small dimension, can be considered as "microstructurally long" and described in the frame of the linear elastic fracture mechanics. The extended finite element method is used to calculate the stress intensity factors along the crack front taking into account the three-dimensional geometry extracted from the tomographic images. For the same nominal value of the stress intensity factor range, crack propagation is faster in the bulk than at the surface. The observed anisotropy is attributed to the variation of the closure stress along the crack front between surface and bulk. The experimentally observed fatigue crack propagation is compared to numerical simulations. Good agreement is found when a linear variation of closure stress along the crack front is taken into account in the "3D crack propagation law" used for the simulation.

Subfields: Mechanical Engineering, Mechanics of Materials

View Paper: https://www.semanticscholar.org/paper/89213ba6abf873c284905e7a58988c736f50b9d6

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In Mechanical Engineering

In Mechanics of Materials

Citations in the corpus

In Situ Experiments with X ray Tomography: an Attractive Tool for Experimental Mechanics (2010, methodology): “It was shown that a single Paris law could account for the propagation only if a variation of the crack closure level was taken into account along the crack front [40].”
Periodic three-dimensional mesh generation for crystalline aggregates based on Voronoi tessellations (2009, methodology): “The X-ray computer (micro-) tomography has been used in the past for various microstructures and for the determination of microcracks [ 14 ,23].”
Voxel-Scale Digital Volume Correlation (2011, background): “For instance, yielding [7] and damage mechanisms [8–10], cracks [17,11,12] are observed in situ.”
A three-dimensional cohesive-frictional grain-boundary micromechanical model for intergranular degradation and failure in polycrystalline materials (2013, background): “Various experimental techniques are available for microstructural characterization [25, 26, 27, 28, 29, 71, 72, 73] and their output is sometimes used as input for finite element (FE) analysis [74, 75, 48, 49].”
Generation of 3D representative volume elements for heterogeneous materials: A review (2018, methodology): “The most commonly available method is X-ray tomography (lCT) [119,120] which allows imaging with a resolution of a few micrometers with desktop instruments.”
Digital image correlation and fracture: an advanced technique for estimating stress intensity factors of 2D and 3D cracks (2009, methodology): “When the crack morphology is determined, X-FEM techniques allow for the evaluation of surface versus bulk propagation features [51].”