Experimental Mechanics

, Volume 10, Issue 9, pp 390–393 | Cite as

A simple method for determining principal-stress directions in embedded-polariscope models

Experiments show that principal-stress directions can be found from isochromatic observations of a perforated embedded layer; also, the full-field isochromatic pattern is little disturbed by the presence of small-diameter perforations
  • R. Mark
  • R. B. Pipes
Article

Abstract

A disadvantage of the embedded-polariscope method is the inability to observe isoclinics because the embedded Polaroid sheets are fixed within the model. Perforating the embedded active layer with an array of small-diameter holes allows observation of stress trajectories in the layer from the isochromatic patterns. Further, it is shown that the full-field fringes are little disturbed by the presence of the small perforations. The techniques of model fabrication are described, as well as an extension of the method to reveal bending-stress trajectories in plates loaded out of plane.

Keywords

Active Layer Circular Polarizer Drilling Operation Cellulose Acetate Butyrate Acetate Butyrate 
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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References

  1. 1.
    Becher, H., andColao, A., “Determining Isoclinics from Fringe Patterns,”Experimental Mechanics,9 (10),469–472 (1969).CrossRefGoogle Scholar
  2. 2.
    Tesar, V., “La Photoélasticimétrie et ses Applications dans les Constructions Aéronautiques,”La Science Aérienne, Paris, 372 (1932).Google Scholar
  3. 3.
    Durelli, A. J., and Murray, W. M., “Stress Distribution around a Circular Discontinuity in any Two-dimensional System of Combined Stress,” Proc. 14th Eastern Photoelasticity Conf., 21–36, (December 1941).Google Scholar
  4. 4.
    Oppel, G. U., “Photoelastic Strain Gages,”Proc. SESA, XVIII (1),65–73 (1961).Google Scholar
  5. 5.
    Timoshenko, S., and Goodier, J. N., Theory of Elasticity, McGraw-Hill, 78–82, (1951).Google Scholar
  6. 6.
    Roberts, A., “A Model of Rock Foundation Problems Underneath a Concrete Gravity Dam,”Strain, Jnl. Brit. Soc. for Strain Measurement,1, (3),4–9 (July1965).Google Scholar
  7. 7.
    Mark, R., “Glycerine Loading of Liquid-storage-tank Photoelastic Models,”Experimental Mechanics,8 (1),47–48 (January1968).CrossRefGoogle Scholar
  8. 8.
    Frocht, M. M., Photoelasticity, Vol. II, J. Wiley and Sons, 150–154 (1958).Google Scholar
  9. 9.
    Kuske, A., “Separation of Principal Stresses by Means of an Improved Shear-difference Method,”Experimental Mechanics,8 (1),45–53 (January1966).CrossRefGoogle Scholar

Copyright information

© Society for Experimental Mechanics, Inc. 1970

Authors and Affiliations

  • R. Mark
    • 1
  • R. B. Pipes
    • 2
  1. 1.Department of Civil and Geological EngineeringPrinceton UniversityPrinceton
  2. 2.General Dynamics-Fort WorthFort Worth

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