Dynamics of reorientation of a constrained nematic elastomer

1999 ◽  
Vol 9 (3) ◽  
pp. 471-477 ◽  
Author(s):  
P.I.C. Teixeira
Keyword(s):  
Nematic Elastomer

Effect of Dynamic Soft Elasticity on Vibration of Embedded Nematic Elastomer Timoshenko Beams

2018 ◽  
Vol 10 (05) ◽  
pp. 1850058 ◽  
Author(s):  
Dong Zhao ◽  
Ying Liu
Keyword(s):  
Low Frequency ◽  
Beam Theory ◽  
Timoshenko Beams ◽  
Analysis Method ◽  
Anisotropic Parameter ◽  
Nematic Elastomer ◽  
Dissipation Mechanism ◽  
Viscous Media ◽  
Complex Modal Analysis ◽  
Soft Elasticity

This paper addresses the transverse vibration of a nematic elastomer (NE) beam embedded in soft viscoelastic surroundings with the aim to clarify a new dissipation mechanism caused by dynamic soft elasticity of this soft material. Based on the viscoelasticity theory of NEs in low-frequency limit and the Timoshenko beam theory, the governing equation of motion is derived by using the Hamilton principle and energy method, and is solved by the complex modal analysis method. The dependence of vibration property on the intrinsic parameters of NEs (director rotation time, rubber relaxation time, anisotropic parameter) and foundation (spring, shear and damping constants) are discussed in detail. The results show that dynamic soft elasticity leads to anomalous anisotropy of energy transfer and attenuation. The relative stiffer foundation would restraint the rubber dissipation of viscoelastic beams, but has less influence on the director rotation dissipation, which is particular for NE beams. This study would provide a useful guidance in the dynamic design of NE apparatus embedded in soft viscous media.

scholarly journals Relaxation of nonlinear elastic energies involving the deformed configuration and applications to nematic elastomers

2019 ◽  
Vol 25 ◽  
pp. 19 ◽  
Author(s):  
Carlos Mora-Corral ◽  
Marcos Oliva
Keyword(s):  
Sobolev Space ◽  
Elastic Energy ◽  
Lower Semicontinuous ◽  
Deformation Gradient ◽  
Variational Model ◽  
Nematic Elastomer ◽  
Nematic Elastomers ◽  
Lower Semicontinuous Envelope ◽  
Nonlinear Elastic

We start from a variational model for nematic elastomers that involves two energies: mechanical and nematic. The first one consists of a nonlinear elastic energy which is influenced by the orientation of the molecules of the nematic elastomer. The nematic energy is an Oseen–Frank energy in the deformed configuration. The constraint of the positivity of the determinant of the deformation gradient is imposed. The functionals are not assumed to have the usual polyconvexity or quasiconvexity assumptions to be lower semicontinuous. We instead compute its relaxation, that is, the lower semicontinuous envelope, which turns out to be the quasiconvexification of the mechanical term plus the tangential quasiconvexification of the nematic term. The main assumptions are that the quasiconvexification of the mechanical term is polyconvex and that the deformation is in the Sobolev space W1,p (with p > n − 1 and n the dimension of the space) and does not present cavitation.

Effects of director rotation relaxation on viscoelastic wave dispersion in nematic elastomer beams

2018 ◽  
Vol 24 (4) ◽  
pp. 1103-1115 ◽  
Author(s):  
Dong Zhao ◽  
Ying Liu
Keyword(s):  
Wave Motion ◽  
Relaxation Times ◽  
Low Frequency ◽  
Wave Dispersion ◽  
Frequency Limit ◽  
Anisotropic Parameter ◽  
Acoustic Design ◽  
Phase Velocities ◽  
Nematic Elastomer ◽  
Viscoelastic Wave

In this paper, the transverse wave dispersion in a nematic elastomer (NE) Timoshenko beam is studied by considering anisotropy and viscoelasticity of NEs in the low frequency limit. Firstly, the characteristic equations of wave motion in an NE beam are derived, and then numerically solved to obtain the corresponding phase velocities and attenuation factors. The influences of anisotropic parameter, director rotation and rubber relaxation times on the wave dispersion in an NE beam are discussed. Results show that unlike the situation in general isotropic viscoelastic beam, non-classical viscoelastic wave dispersion is found in NE beams. Geometric dispersion is restrained with the vanishing of cut-off frequencies for shear waves due to director rotation relaxation of NEs. This unique property promises prospective applications of NE beams in optic or acoustic design.

Uniaxial tension of a nematic elastomer with inclined mesogens

2020 ◽  
Vol 40 ◽  
pp. 100936
Author(s):  
Xuming He ◽  
Yue Zheng ◽  
Qiguang He ◽  
Shengqiang Cai
Keyword(s):  
Uniaxial Tension ◽  
Nematic Elastomer

scholarly journals Patterning order and disorder with an angle: modeling single-layer dual-phase nematic elastomer ribbons

RSC Advances ◽  
2019 ◽  
Vol 9 (16) ◽  
pp. 8994-9000
Author(s):  
Vianney Gimenez-Pinto ◽  
Fangfu Ye
Keyword(s):  
Sample Size ◽  
Liquid Crystalline ◽  
Single Layer ◽  
Domain Size ◽  
Dual Phase ◽  
Order And Disorder ◽  
Nematic Elastomer ◽  
The Rich ◽  
Design Factors

We study the rich actuation variety displayed by elastomers that combine well-defined isotropic regions and liquid crystalline regions. Design factors for actuation include orientation of director and pattern, domain-size and sample-size.

scholarly journals Thermal diffusion and bending kinetics in nematic elastomer cantilever

2008 ◽  
Vol 25 (1) ◽  
pp. 83-89 ◽  
Author(s):  
K. K. Hon ◽  
D. Corbett ◽  
E. M. Terentjev
Keyword(s):  
Thermal Diffusion ◽  
Nematic Elastomer

scholarly journals Bending kinetics of a photo-actuating nematic elastomer cantilever

2011 ◽  
Vol 99 (25) ◽  
pp. 254102 ◽  
Author(s):  
N. Torras ◽  
K. E. Zinoviev ◽  
J. E. Marshall ◽  
E. M. Terentjev ◽  
J. Esteve
Keyword(s):  
Nematic Elastomer ◽  
Kinetics Of

scholarly journals Programming complex shapes in thin nematic elastomer and glass sheets

2016 ◽  
Vol 94 (1) ◽  
Author(s):  
Paul Plucinsky ◽  
Marius Lemm ◽  
Kaushik Bhattacharya
Keyword(s):  
Nematic Elastomer ◽  
Complex Shapes

Disclinations in a homogenously deformed nematic elastomer

2006 ◽  
Vol 18 (5) ◽  
pp. 259-280 ◽  
Author(s):  
E. Fried ◽  
Bidhan C. Roy
Keyword(s):  
Nematic Elastomer
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