Advertisement

Abstract

The basic principles of photoelasticity have been known for many years.1 This chapter deals with how they are used in transducers to measure strain, load and stress. The photoelastic effect is dealt with briefly in order to explain what is happening within the transducers. The linear relationship between fringe order and strain or stress in the birefringent material is emphasised.

Keywords

Principal Stress Principal Strain Fringe Pattern Thermal Error Quarter Wave Plate 
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.

Notation

E

Modulus of elasticity

E

Modulus of elasticity

K

Dimensionless constant representing the optical strain sensitivity of the birefringent materials

N

Number of fringes

k

Ratio of principal stresses

l

Length of light path

εx

Major principal strain

εy

Minor principal strain

λ

Wavelength of light

μ

Poisson’s ratio

σx

Major principal stress

σy

Minor principal stress

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Frocht, M. M. Photoelasticity, vol. 1 (1941) and vol. 2 (1948), John Wiley, Chichester.Google Scholar
  2. 2.
    Zienkiewicz, O. C. and Holister, G. S. Three-dimensional photoelasticity, chapter 13 in: Stress Analysis, 1965, John Wiley, Chichester.Google Scholar
  3. 3.
    Photolastic Inc. (Malvern, Pennsylvania). Introduction to stress analysis by the photoelastic coating technique. Tech. Bulletin TDG-1, 1974.Google Scholar
  4. 4.
    Hawkes, I., Dhir, R. K. and Rose, H. Civ. Eng., 59, 1964, 1536–40.Google Scholar
  5. 5.
    Hawkes, I. and Fellers, G. E. Int. J. Rock Mech. & Min. Sci., 6, 1969, 143–58.CrossRefGoogle Scholar
  6. 6.
    Buswell, H. J., Moore, D. R. and Owens, A. Expt. Mech., 14, 1974, 274–80.CrossRefGoogle Scholar
  7. 7.
    Hawkes, I. Strain, 3, 1967, 1–7.CrossRefGoogle Scholar
  8. 8.
    Photolastic Inc. (Malvern, Pennsylvania). Corrections to photoelastic coating fringe order measurements. Tech. Bulletin T-405, 1977.Google Scholar
  9. 9.
    Hooper, J. A. The theory and development of load cells incorporating photoelastic glass disc transducers. PhD Thesis, Sheffield University, 1968.Google Scholar
  10. 10.
    Coutinho, A. Int. Assoc. for Bridge & Struct. Eng. Pub., 7, 1949.Google Scholar
  11. 11.
    Barron, K. Mines Branch, Dept. Mines Tech. Survey, Ottawa, 1964.Google Scholar
  12. 12.
    CIRIA (London). Instrumentation investigations in Clywedog dam. Technical Note No. 9, 1970.Google Scholar

Copyright information

© Applied Science Publishers Ltd 1983

Authors and Affiliations

  • D. R. Moore
    • 1
  1. 1.AVT Engineering ServicesStockportUK

Personalised recommendations