Digital volume correlation analyses of synchrotron tomographic images

Julien Réthoré (1) , Nathalie Limodin (2, 3) , Jean-Yves Buffiere (3) , François Hild (4) , Wolfgang Ludwig (3, 5) , Stéphane Roux (4)

1 LaMCoS - Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne]
2 LML - Laboratoire de Mécanique de Lille - FRE 3723
3 MATEIS - Matériaux, ingénierie et science [Villeurbanne]
4 LMT - Laboratoire de Mécanique et Technologie
5 ESRF - European Synchrotron Radiation Facility

Three-dimensional (3D) images of nodular graphite cast-iron samples obtained with synchrotron tomography are analysed by resorting to digital volume correlation. This technique uses the material microstructure to measure displacement fields within a sample submitted to mechanical loading. Compared to classical two-dimensional (2D) digital image correlation, the reconstructed volumes used by DVC tend to increase the uncertainty in the correlation calculations, yet elastic strains of the order of 10-3 can be measured. Displacement fields around the front of a fatigue crack have also been measured by an extended version of DVC, and are used to extract stress intensity factors (in modes I, II, and III) along the crack front. The values are in good agreement with finite element calculations when the experimentally measured displacements prescribed on the sample boundaries are considered as input in the numerical simulations.

Mots clés: elastic properties; full-field measurements; measurement uncertainties; stress intensity factor; x-ray tomography

Domaines: Mécanique des matériaux [physics.class-ph]; Mécanique des matériaux [physics.class-ph]

Julien Réthoré, Nathalie Limodin, Jean-Yves Buffiere, François Hild, Wolfgang Ludwig, et al.. Digital volume correlation analyses of synchrotron tomographic images. Journal of Strain Analysis for Engineering Design, 2011, 46, pp.683-695. ⟨10.1177/0309324711409999⟩. ⟨hal-00624446⟩