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Rise of the Poisson’s Ratio in f.c.c. Hard Sphere Crystals with the Narrowest Orthogonal Nanochannels Filled by Hard Spheres of Another Diameter

Narojczyk Jakub W., Tretiakov Konstantin V., Wojciechowski Krzysztof W.

Computational Methods in Science and Technology

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2022

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Vol. 28, No. 2

61--75

EN

Auxetic materials, i.e. materials exhibiting negative Poisson’s ratio, stand to answer the demand for novel materials with unique and application-tailored properties. The vast range of potential applications motivates researchers to search for new materials with such properties, or to look for ways to modify the properties of existing materials. The study of systems with structural inclusions falls into the latter category. This work reports numerical investigations of elastic properties of hard sphere f.c.c. crystal. The investigations have been focused on Monte Carlo simulations of systems with arrays of inclusions filled by hard spheres of different diameter, resulting in binary systems, i.e. systems composed of two kinds of particles that differ only in size. Two different layouts of narrow nanoinclusions have been studied in the isobaricisothermal ensemble. It has been shown that even the narrowest inclusions can significantly alter elastic properties of hard particle crystal by eliminating auxetic properties while maintaining the effective cubic symmetry.

2

Poisson’s Ratio of Yukawa Systems with Nanoinclusions: Nanochannel vs. Nanolayer

Tretiakov Konstantin V., Wojciechowski Krzysztof W., Narojczyk J. W., Pigłowski Paweł M.

Computational Methods in Science and Technology

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2022

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Vol. 28, No. 3

81--85

EN

The influence of periodically distributed inclusions on elastic properties of crystals in which particles interact through Yukawa potential is discussed briefly. The inclusions in the form of channels oriented along the [001]-direction and layers orthogonal to the [010]-direction are considered. Monte Carlo simulations have shown that, depending on the type of inclusion and the concentration of inclusion particles in Yukawa crystal, qualitative changes in elastic properties occur. In selected directions, one observes appearance of auxetic properties for systems with nanolayers and enhancement of auxeticity for systems with nanochannels.

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Smart Cellular Systems with Pressure Dependent Poisson’s Ratios

Attard D., Cauchi R., Gatt R., Grima-Cornish J. N., Grima J. N.

Computational Methods in Science and Technology

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2020

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Vol. 26, No. 2

37--45

EN

The Poisson’s ratio behaviour of cellular systems which change their internal features when subjected to pressure change to become a “re-entrant” or “non-re-entrant” honeycomb was investigated. It was shown, through finite elements simulations, that these changes in geometry permit the systems to exhibit a wide range of Poisson’s ratios, the magnitude and sign of which can be controlled through the external pressure. Auxetic behaviour was also shown to be obtainable at specific pressures with the right combination of design and materials.

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Metamateriały mechaniczne wytwarzane w sposób przyrostowy

Knitter R., Królikowski T.

Mechanik

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2018

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R. 91, nr 7

502--504

PL

Przedstawiono pierwszą fazę prac, która obejmowała badania mechanizmów metamaterialnych z gumopodobnych tworzyw sztucznych, a także wpływu ich struktury i geometrii na przenoszenie zadanej siły oraz przemieszczenia w zaprojektowanym modelu, wykonanym techniką przyrostową FDM (fused deposition modeling). Celem pracy jest ustalenie wpływu parametrów technologicznych oraz zmian geometrii i wypełnienia na parametry wytrzymałościowe wytwarzanego obiektu, a także rozważenie możliwości zastąpienia klasycznych zespołów elementów mechanicznych elementami wykonanymi z użyciem struktur metamaterialnych.

EN

Presented is the first phase of work, which concerned the study of metamaterial mechanisms made of rubber-like plastics, and the impact of their structure and geometry on the transfer of a given force and displacement in a designed model, made using FDM (fused deposition modeling). The aim of the work is to examine the impact of technological parameters and changes in geometry and filling on the strength parameters of the manufactured object and further considerations on replacing the classic assemblies of mechanical elements with elements made using metamaterial structures.