3D Tomographic case

Study of a 3D fatigue crack

Material and Specimen Preparation

The studied material is a nodular graphite cast iron for which the random dispersion of graphite nodules provides a fine 3D random texture that is very well suited for image correlation. The graphite nodules are homogeneously distributed inside the matrix and are nearly spherical with an average diameter of 45µm.

Experimental set-up

The tomography experiment was performed on ID19 beamline at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. A monochromatic X-ray beam traverses the sample (Figure below). 600 radiographs were taken while the sample was rotating over 180° along its vertical axis; the total scan time was equal to 42 min. A specially designed fatigue machine allows for in-situ loading and high frequency cycling (50 Hz), of the specimen. A PMMA tube, almost transparent to X-rays, is used as a load rig. The machine is directly mounted on the rotating stage of the beam line.

3D correlation diagram

Results

It is possible to identify the crack front using the residue.

Crack front identified using image residue.

Crack front identified using image residue.

 

Download a test case for 3D tomographic applications.

here, a zip file that contains the following files.
Number of download: 450

  • A set of 3D tomographic volume taken from Limodin's work [1]
  • A parameter file
  • A python file for plotting data (3d rendering)
  • a preview of results

    • Please visit the web site of the LML's X-Ray tomography platform, for more information about X-Ray tomography facilities.

    [1] N. Limodin, J. Réthoré, J. Buffière, F. Hild, W. Ludwig, J. Rannou, and S. Roux, "3d x-ray microtomography volume correlation to study fatigue crack growth," Advanced engineering materials, vol. 13, iss. 3, pp. 186-193, 2011.
    [Bibtex]
    @article{Limodin2011,
title={3D X-ray Microtomography Volume Correlation to Study Fatigue Crack Growth},
author={Limodin, Nathalie and R{\'e}thor{\'e}, Julien and Buffi{\`e}re, Jean-Yves and Hild, Fran{\c{c}}ois and Ludwig, Wolfgang and Rannou, Johann and Roux, St{\'e}phane},
journal={Advanced Engineering Materials},
volume={13},
number={3},
pages={186--193},
year={2011},
publisher={Wiley Online Library}
}