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On the properties of real finite‐sized planar and tubular stent‐like auxetic structures
Author(s) -
Gatt Ruben,
CaruanaGauci Roberto,
Attard Daphne,
Casha Aaron R.,
Wolak Wiktor,
Dudek Krzysztof,
Mizzi Luke,
Grima Joseph N.
Publication year - 2014
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201384257
Subject(s) - auxetics , moduli , planar , poisson's ratio , deformation (meteorology) , poisson distribution , geometry , property (philosophy) , mathematics , physics , materials science , computer science , composite material , philosophy , statistics , computer graphics (images) , epistemology , quantum mechanics
Auxetics, i.e. systems with a negative Poisson's ratio, exhibit the unexpected property of becoming wider when stretched and narrower when compressed. This property arises from the manner in which the internal geometric units within the system deform when the system is submitted to a stress and may be explained in terms of ‘geometry–deformation mechanism’ based models. This work considers realistic finite implementations of the well known rotating squares system in the form of (i) a finite planar structure and (ii) a tubular conformation, as one typically finds in stents. It shows that although the existing models of the Poisson's ratios and moduli based on periodic systems may be appropriate to model systems where the geometry/deformation mechanism operate at the micro‐ or nano‐ (molecular) level where a system may be considered as a quasi infinite system, corrections to the model may need to be made when one considers finite structures with a small number of repeat units and suggests that for finite systems, especially for the 2D systems, the moduli as predicted by the periodic model may be significantly overestimating the moduli of the real system, even sometimes by as much as 200%.