Chapter 45. Laser Speckle Micro-Strain Measurements on Small Diameter Fibers

  1. John B. Wachtman Jr.
  1. Ali Sayir,
  2. Lawrence C. Greer III,
  3. Jon C. Goldsby and
  4. Lawrence G. Oberle

Published Online: 28 MAR 2008

DOI: 10.1002/9780470314500.ch45

Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - A: Ceramic Engineering and Science Proceedings, Volume 15, Issue 4

Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - A: Ceramic Engineering and Science Proceedings, Volume 15, Issue 4

How to Cite

Sayir, A., Greer, L. C., Goldsby, J. C. and Oberle, L. G. (1994) Laser Speckle Micro-Strain Measurements on Small Diameter Fibers, in Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - A: Ceramic Engineering and Science Proceedings, Volume 15, Issue 4 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314500.ch45

Author Information

  1. National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio 44135

Publication History

  1. Published Online: 28 MAR 2008
  2. Published Print: 1 JAN 1994

ISBN Information

Print ISBN: 9780470375327

Online ISBN: 9780470314500

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Keywords:

  • micro-strain;
  • micro-strain;
  • deformation;
  • displacement;
  • speckle

Summary

Micro-strain measurements of small diameter fibers were performed using Yamaguchi's speckle-shift technique. This novel technique requires no specimen surface preparation and allows micro-strain measurements for an extremely small gauge length (on the order of 0.1 mm). It provides a strain resolution of approximately 15 micro-strain (μ.e). Studies performed at room temperature have demonstrated that the system can be used to measure strain in ceramic Fibers and metal wires as small as 21 μm in diameter. These micro-strain measurements were used to determine Young's modulus of sapphire, silicon carbide and polycrystalline alumina fibers. The results obtained were in excellent agreement with literature values.