Experimental Mechanics

, Volume 10, Issue 2, pp 64–71 | Cite as

Two systems for automatic reduction of time-dependent photomechanics data

The use of the analog method implemented by the electrnic servo system described in this paper is reported to allow accurate translation of the fringe-order history into a stress history
  • Charless W. Fowlkes


Time-dependent photomechanical model materials will not, in general, exhibit a one-to-one relationship between the instantaneous stress and the relative retardation. Due to the complicated nature of this relationship, it is often more accurate to use the analog method of data reduction. This method consists of reproducing the fringe-order history observed in the model in a tensile specimen of the model material and recording the corresponding stress history. Two servo systems are described in this report which may be programmed to produce a desired fringe-order history in a time-dependent tensile specimen.


Mechanical Engineer Fluid Dynamics Model Material Data Reduction Tensile Specimen 
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  1. 1.
    Durelli, A. J. and Riley, W. F., Introduction to Photomechanics, Prentice-Hall (1965).Google Scholar
  2. 2.
    Coker, E. andFilon, L., Treatise on Photoelasticity, London, Cambridge University Press (1931).Google Scholar
  3. 3.
    Dill, E. H. and Fowlkes, C. W., “Photoviscoelasticity,” NASA CR-444 (May 1966).Google Scholar
  4. 4.
    Daniel, I. M., “Two-Dimensional Dynamic Stress Analysis in a Nonelastic Material,” Tech. Doc. Report No. RTD-TDR-63-3059, Air Force Weapons Lab., Kirtland Air Force Base, N. M. Google Scholar
  5. 5.
    Theocaris, P. S., “A Review of the Rheo-Optical Properties of Linear High Polymers,”Experimental Mechanics,5 (4)105–114 (1965).CrossRefGoogle Scholar
  6. 6.
    Frocht, M. M. and Thomson, R. A., “Studies in Photoplasticity”, Proc. Third U. S. Natl. Cong. Appl. Mech. (June 1958).Google Scholar
  7. 7.
    Arenz, R. J., Ferguson, C. W., andWilliams, M. L., “The Mechanical and Optical Properties of a Solithane 113 Composition,”Experimental Mechanics,7 (4)183–188 (1967).CrossRefGoogle Scholar
  8. 8.
    Fowlkes, C. W., “Two Photoviscoelasticity Experiments Using Analog Data Reduction,”Experimental Mechanics,17 (1)41–46 (1967).Google Scholar
  9. 9.
    Mindlin, R. D., “A Muthematical Theory of Photoviscoelasticity,”Jnl. Appl. Phys.,20,206–216 (1949).MATHGoogle Scholar
  10. 10.
    Foulkes, C. W., “Photoviscoelastic Model Testing,” NASA CR-1289 (February 1969).Google Scholar

Copyright information

© Society for Experimental Mechanics, Inc. 1970

Authors and Affiliations

  • Charless W. Fowlkes
    • 1
  1. 1.College of Engineering, Department of Aeronautics and AstronauticsUniversity of WashingtonSeattle

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