Results 221 to 230 of about 3,728 (241)

Origin of anisotropic negative Poisson's ratio in graphene

Nanoscale, 2018
The underlying mechanism and the electronic origin for the anisotropic NPR in graphene along zigzag and armchair directions are both well-understood based on the accurate first-principles study.
Zhenzhen Qin, Guangzhao Qin, Ming Hu
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A negative Poisson’s ratio carbon fibre composite using a negative Poisson’s ratio yarn reinforcement

Composites Science and Technology, 2012
Abstract The manufacture of negative Poisson’s ratio (auxetic) composites, containing inherently auxetic phases is rare and has been confined to relatively low modulus composite systems with stiffnesses several orders of magnitude below those of structural composites. This paper presents the use of an auxetic double helix yarn that is used to produce
W. Miller, Z. Ren, C.W. Smith, K.E. Evans   +3 more
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Oxidation-induced negative Poisson’s ratio of phosphorene

Journal of Physics: Condensed Matter, 2018
Abstract Mechanical properties of phosphorene oxides are investigated by using density functional theory calculations. Intriguingly, as the oxygen coverage approaches 50%, negative Poisson’s ratios are found in the in-plane principal directions, originating from the asymmetric atomic structure upon oxygen adsorption.
Feng Hao, Xiangbiao Liao, Mingjia Li, Hang Xiao, Xi Chen   +4 more
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Tailoring Graphene to Achieve Negative Poisson's Ratio Properties

Advanced Materials, 2014
Graphene can be made auxetic through the introduction of vacancy defects. This results in the thinnest negative Poisson's ratio material at ambient conditions known so far, an effect achieved via a nanoscale de-wrinkling mechanism that mimics the behavior at the macroscale exhibited by a crumpled sheet of paper when stretched.
Grima J. N., Winczewski S., Mizzi L., Grech M. C., Cauchi R., Gatt R., Attard D., Wojciechowski K. W., Rybicki J.   +8 more
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Example of a Negative Effective Poisson's Ratio

Physical Review Letters, 1981
An effective Poisson's ratio is introduced for anisotropic materials as the negative ratio of transverse and longitudinal strains averaged over all transverse directions. It is shown that for certain orientations of the applied force this effective Poisson's ratio assumes negative values for $\ensuremath{\alpha}$-quartz.
E. Kittinger, J. Tichý, E. Bertagnolli
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Negative Poisson’s Ratio Polyester Fibers

Textile Research Journal, 2006
Auxetic materials are referred to as those having negative Poisson’s ratio (ν). Initial work at Bolton successfully fabricated auxetic polypropylene fiber using a novel thermal melt-spinning technique. This paper reports in detail both the methods and principles involved in screening polyester powder and also the manufacturing method for successful ...
Naveen Ravirala, Kim L. Alderson, Philip J. Davies, Virginia R. Simkins, Andrew Alderson   +4 more
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On the negative poisson ratio in monocrystalline zinc

Scripta Materialia, 1999
Consider an anisotropic body with the elastic compliance coefficients Sijkl, relative to an orthogonal coordinate system. If the body is loaded uniaxially by stress sn in the direction defined by unit vector n, the stress components are sij 5 sn ninj, with the corresponding strains eij 5 sn Sijkl nknl. The longitudinal strain in the direction n is thus
V.A Lubarda, M.A Meyers
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Natrolite: A zeolite with negative Poisson’s ratios

Journal of Applied Physics, 2007
The recently published experimental elastic constants [C. Sanchez-Valle, S. V. Sinogeikin, Z. A. Lethbridge, R. I. Walton, C. W. Smith, K. E. Evans, and J. D. Bass, J. Appl. Phys. 98, 053508 (2005)] for single crystals of the orthorhombic aluminosilicate zeolite NAT (natrolite, Na2(Al2Si3O10)2H2O, Fdd2) throw valuable light on the potential of NAT as a
Joseph N. Grima, Ruben Gatt, Victor Zammit, Jennifer J. Williams, Kenneth E. Evans, Andrew Alderson, Richard I. Walton   +6 more
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Advances in negative Poisson's ratio materials

Advanced Materials, 1993
Solids that become fatter in cross‐section when stretched are rare, but do exist. How such materials—which have a negative Poisson's ratio—can be created with specific properties, the implications of these unusual properties, and recent advances are discussed.
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Directions with negative Poisson’s ratio in crystals

The Journal of the Acoustical Society of America, 2001
Materials with negative Poisson’s ratio are peculiar in that they expand laterally when stretched. The Poisson’s ratio is the ratio of lateral strain in the direction n to the longitudinal strain during the stretching of a cylindrical rod along rod axis m.
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