University of Illinois Urbana-Champaign

Normal-stress differences and the detection of disclinations in nematic elastomers

Fried, Eliot; Todres, Russell E.

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https://hdl.handle.net/2142/272

Description

Title
Normal-stress differences and the detection of disclinations in nematic elastomers
Author(s)
  • Fried, Eliot
  • Todres, Russell E.
Issue Date
2002-06
Keyword(s)
  • constitutive theory
  • smart materials
  • experimental fluid mechanics
  • granular materials
  • particulate flows
  • phase transitions
  • biological mechanics
Abstract
We use a continuum model to investigate the isochoric radial expansion of a right circular cylindrical specimen composed of a nematic elastomer that is cross-linked in a uniaxial state and then annealed. Numerical solutions show that, above a certain radial expansion, the material has a definitive energetic preference for a state involving a disclination of strength +1 along the cylinder axis. Surrounding such a disclination is a core with radial dimension on the order of 10^-2 µm, which coincides with observations in conventional liquid-crystal melts. Examination of the normal-stress differences shows that the first of these differences depends non-monotonically on the extent of radial expansion and possesses a local minimum at the point where a disclination becomes energetically preferred. This suggests a practical experimental method for testing the predictions of our model.
Publisher
Department of Theoretical and Applied Mechanics (UIUC)
Series/Report Name or Number
TAM Reports 1004
ISSN
0073-5264
Type of Resource
text
Language
en
Permalink
http://hdl.handle.net/2142/272

Owning Collections

Technical Reports - Theoretical and Applied Mechanics (TAM) PRIMARY
TAM technical reports include manuscripts intended for publication, theses judged to have general interest, notes prepared for short courses, symposia compiled from outstanding undergraduate projects, and reports prepared for research-sponsoring agencies.