Compressive properties of auxetic structures produced with direct 3D printing

0464513 - ÚTAM 2017 RIV SI eng J - Článek v odborném periodiku
Koudelka_ml., Petr - Jiroušek, O. - Fíla, Tomáš - Doktor, Tomáš
Compressive properties of auxetic structures produced with direct 3D printing.
Materiali in Tehnologije. Roč. 50, č. 3 (2016), s. 311-317. ISSN 1580-2949. E-ISSN 1580-3414
Grant CEP: GA ČR(CZ) GAP105/12/0824
Institucionální podpora: RVO:68378297
Klíčová slova: auxetics * cellular materials * quasi-static testing * finite-element method
Kód oboru RIV: JJ - Ostatní materiály
Impakt faktor: 0.436, rok: 2016
http://mit.imt.si/Revija/izvodi/mit163/koudelka.pdf

In the presented paper, three types of auxetic structures were produced with direct 3D printing and their compressive mechanical properties were tested. Samples were prepared from acrylic material suitable for high-resolution direct printing. Three different structures exhibiting in-plane and volumetric negative strain-dependent Poisson’s ratio were selected for the analysis: two-dimensional missing-rib cut, two-dimensional inverted (re-entrant) honeycomb and three-dimensional inverted (re-entrant) honeycomb. The samples were subjected to quasi-static compression, from which stress-strain relationships were established.
For a proper strain evaluation, digital-image correlation was applied to measure full-field displacements on the sample surfaces. From the displacement fields, true strain/true stress curves were derived for each sample. Furthermore, for each structure a three-dimensional FE model was developed using beam elements and subjected to identical loading conditions. Then, experimentally obtained stress-strain relationships were compared with numerically obtained results. For all the tested auxetic structures, the compressive behaviour was predicted well by the FE models. This demonstrates that parametric FE models can be used to tune the design parameters of the structures with a negative Poisson’s ratio to optimize their overall properties.
Trvalý link: http://hdl.handle.net/11104/0263393