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Experimental Mechanics

, Volume 30, Issue 3, pp 224–229 | Cite as

Highlights of the optical anisotropy of unstressed transparent polymeric plates

  • Sameh S. Issa
Article

Abstract

The photoelastic effect is cumulative, therefore the presence of material birefringence in unstressed transparent polymers might lead to erroneous photoelastic analyses. This presence is more influential in the scattered-light photoelasticity. Direct-transmission polariscopes are not suitable for detecting all material birefringence in normally illuminated plates because the birefringence in question coincides with the wave normal of the propagating light. The present paper describes phenomenologically the presence of the material birefringence in an arbitrarily selected group of unstressed cross-linked polymers and presents means of their determination. The material-birefringence information obtained can be used as a means of taking proper precautions for conducting faultless scattered-light photoelastic analyses. Octagonally shaped plates were machined to permit data acquisition using four different light-propagation directions. The orientation and diffusion of molecular chains appear to be the major source of the material birefringence observed.

Keywords

Polymer Anisotropy Mechanical Engineer Data Acquisition Fluid Dynamics 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Society for Experimental Mechanics, Inc. 1990

Authors and Affiliations

  • Sameh S. Issa
    • 1
  1. 1.Civil Engineering DepartmentKuwait UniversitySafat

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