TY - JOUR
T1 - In situ X-ray synchrotron tomographic imaging during the compression of hyper-elastic polymeric materials
AU - Patterson, Brian M.
AU - Cordes, Nikolaus L.
AU - Henderson, Kevin
AU - Williams, Jason J.
AU - Stannard, Tyler
AU - Singh, Sudhanshu S.
AU - Ovejero, Angel Rodriguez
AU - Xiao, Xianghui
AU - Robinson, Mathew
AU - Chawla, Nikhilesh
N1 - Funding Information:
The authors wish to thank Doga Gursoy with his advice in using Tomopy and Tim Mooney for programming the beamline operation. Los Alamos National Laboratory is operated by Los Alamos National Security LLC under contract number DE-AC52-06NA25396 for the US Department of Energy. This research used resources of the Advanced Photon Source, a U. S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Funding for this research was provided by the Enhanced Surveillance Campaign, Tom Zocco, Program Manager and the Engineering Campaign, Eric Mas, Program Manager.
Publisher Copyright:
© 2015, Springer Science+Business Media New York.
PY - 2015/9/8
Y1 - 2015/9/8
N2 - Cellular structures are present in many modern and natural materials and their proper utilization is crucial within many industries. Characterizing their structural and mechanical properties is complicated, in that they often have a stochastic cellular structure, and in addition, they often have hyper-elastic (i.e., non-linear) mechanical properties. Understanding the 3D structure and the dynamic response of polymer foams to mechanical stress is a key to predicting lifetime performance, damage pathways, and stress recovery. Therefore, to gain a more complete picture, experiments which are designed to understand their mechanical properties must simultaneously acquire performance metrics during loading. In situ synchrotron X-ray computed tomography can image these cellular materials in 3D during uniaxial compression at a 10−2 s−1 strain rate. By utilizing the high X-ray photon flux and high-speed camera provided by beamline 2-BM at the advanced photon source, it is possible to collect a full 3D tomogram (900 radiographs as the sample is rotated 180°) within 1 s. Rotating the sample stage in a washing machine motion allows for a 1 s tomogram to be collected every fifth second. In this study, a series of 20 tomograms were collected as the sample was continuously stressed to a nominal 60 % compression. Several types of silicone foams with various structures were used to explore this technique. Stress–strain curves, collected simultaneously with the 3D tomograms, can be used to directly correlate the morphology with the mechanical performance and visualize in real-time, the buckling of ligaments. In addition, this method allows for the accurate measurement of the Poisson’s ratio as a function of compression. Coupling this moderate strain rate 3D data with finite element analysis provides a direct comparison between the true mechanical response and the modeled performance and adds a level of robustness that is not possible with other techniques.
AB - Cellular structures are present in many modern and natural materials and their proper utilization is crucial within many industries. Characterizing their structural and mechanical properties is complicated, in that they often have a stochastic cellular structure, and in addition, they often have hyper-elastic (i.e., non-linear) mechanical properties. Understanding the 3D structure and the dynamic response of polymer foams to mechanical stress is a key to predicting lifetime performance, damage pathways, and stress recovery. Therefore, to gain a more complete picture, experiments which are designed to understand their mechanical properties must simultaneously acquire performance metrics during loading. In situ synchrotron X-ray computed tomography can image these cellular materials in 3D during uniaxial compression at a 10−2 s−1 strain rate. By utilizing the high X-ray photon flux and high-speed camera provided by beamline 2-BM at the advanced photon source, it is possible to collect a full 3D tomogram (900 radiographs as the sample is rotated 180°) within 1 s. Rotating the sample stage in a washing machine motion allows for a 1 s tomogram to be collected every fifth second. In this study, a series of 20 tomograms were collected as the sample was continuously stressed to a nominal 60 % compression. Several types of silicone foams with various structures were used to explore this technique. Stress–strain curves, collected simultaneously with the 3D tomograms, can be used to directly correlate the morphology with the mechanical performance and visualize in real-time, the buckling of ligaments. In addition, this method allows for the accurate measurement of the Poisson’s ratio as a function of compression. Coupling this moderate strain rate 3D data with finite element analysis provides a direct comparison between the true mechanical response and the modeled performance and adds a level of robustness that is not possible with other techniques.
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U2 - 10.1007/s10853-015-9355-8
DO - 10.1007/s10853-015-9355-8
M3 - Article
AN - SCOPUS:84946492102
SN - 0022-2461
VL - 51
SP - 171
EP - 187
JO - Journal of Materials Science
JF - Journal of Materials Science
IS - 1
ER -