EPJ Web Conf.
Volume 183, 2018DYMAT 2018 - 12th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading
|Number of page(s)||6|
|Published online||07 September 2018|
Testing of Auxetic Materials Using Hopkinson Bar and Digital Image Correlation
Czech Technical University in Prague, Faculty of Transportation Sciences,
2 Universität des Saarlandes, Institute of Applied Mechanics, Campus A4.2, Saarbrücken, 66123, Germany
3 Czech Academy of Sciences, Institute of Theoretical and Applied Mechanics, Prosecká 76, 190 00 Prague, Czech Republic
* e-mail: firstname.lastname@example.org
Published online: 7 September 2018
In this paper, a split Hopkinson pressure bar (SHPB) was used for impact loading of an auxetic lattice (structure with negative Poisson’s ratio) at a given strain-rate. High strength aluminum and polymethyl methacrylate bars instrumented with foil strain-gauges were used for compression of an additively manufactured missing-rib auxetic lattice. All experiments were observed using a high-speed camera with frame-rate set to approx. 135.000 fps. High-speed images were synchronized with the strain-gauge records. Dynamic equilibrium in the specimen was analyzed and optimized pulse-shaping was introduced in the selected experiments. Longitudinal and lateral in-plane displacements and strains were evaluated using digital image correlation (DIC) technique. DIC results were compared with results obtained from strain-gauges and were found to be in good agreement. Using DIC, it was possible to analyze in-plane strain distribution in the specimens and to evaluate strain dependent Poisson’s ratio of the auxetic structure.
© The Authors, published by EDP Sciences, 2018
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.