Geometry: The leading parameter for the Poisson's ratio of bending-dominated cellular solids

Mitschke H, Schury F, Mecke K, Wein F, Stingl M, Schroder-Turk GE (2016)

Publication Status: Published

Publication Type: Journal article

Publication year: 2016

Journal

Publisher: PERGAMON-ELSEVIER SCIENCE LTD

Book Volume: 100

Pages Range: 1-10

DOI: 10.1016/j.ijsolstr.2016.06.027

Abstract

Control over the deformation behaviour that a cellular structure shows in response to imposed external forces is a requirement for the effective design of mechanical metamaterials, in particular those with negative Poisson's ratio. This article sheds light on the old question of the relationship between geometric microstructure and mechanical response, by comparison of the deformation properties of bar-and-joint frameworks with those of their realisation as a cellular solid made from linear-elastic material. For ordered planar tessellation models, we find a classification in terms of the number of degrees of freedom of the framework model: first, in cases where the geometry uniquely prescribes a single deformation mode of the framework model, the mechanical deformation and Poisson's ratio of the linearly-elastic cellular solid closely follow those of the unique deformation mode; the result is a bending-dominated deformation with negligible dependence of the effective Poisson's ratio on the underlying material's Poisson's ratio and small values of the effective Young's modulus. Second, in the case of rigid structures or when geometric degeneracy prevents the bending-dominated deformation mode, the effective Poisson's ratio is material-dependent and the Young's modulus (E) over tilde (cs) large. All analysed structures of this type have positive values of the Poisson's ratio and large values of (E) over tilde (cs). Third, in the case, where the framework has multiple deformation modes, geometry alone does not suffice to determine the mechanical deformation. These results clarify the relationship between mechanical properties of a linear-elastic cellular solid and its corresponding bar-and-joint framework abstraction. They also raise the question if, in essence, auxetic behaviour is restricted to the geometry-guided class of bending-dominated structures corresponding to unique mechanisms, with inherently low values of the Young's modulus. (C) 2016 Elsevier Ltd. All rights reserved.

Authors with CRIS profile

Additional Organisation(s)

Involved external institutions

Murdoch University Australia (AU)

How to cite

APA:

Mitschke, H., Schury, F., Mecke, K., Wein, F., Stingl, M., & Schroder-Turk, G.E. (2016). Geometry: The leading parameter for the Poisson's ratio of bending-dominated cellular solids. International Journal of Solids and Structures, 100, 1-10. https://doi.org/10.1016/j.ijsolstr.2016.06.027

MLA:

Mitschke, Holger, et al. "Geometry: The leading parameter for the Poisson's ratio of bending-dominated cellular solids." International Journal of Solids and Structures 100 (2016): 1-10.

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