Experimental Mechanics

, Volume 27, Issue 2, pp 184–189 | Cite as

Use of photoelasticity to determine orthotropicK I stress-intensity factor

  • M. Mojtahed
  • L. W. Zachary


A new experimental method of obtaining orthotropic stress-intensity factor,K I , is presented. The orthotropic photoelasticity and orthotropic linear-elastic fracture-mechanics laws are combined. The combined set of equations is used along with half-fringe photoelasticity to determineK I in a compact-tension specimen made of a transparent unidirectional fiberglass-epoxy material. The results are compared with finite-element-method solutions.


Mechanical Engineer Fluid Dynamics Experimental Method 
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  1. 1.
    Liebowitz, H., Fracture,I–VII,Academic Press, Inc.,New York (1968).Google Scholar
  2. 2.
    Broek, D., Elementary Engineering Fracture Mechanics, Martinus Nijhoff Pub., Boston, MA (1982).Google Scholar
  3. 3.
    Kobayashi, A. S., Experimental Techniques in Fracture Mechanics, and 2,The Iowa State Univ. Press,Ames, IA (1975).Google Scholar
  4. 4.
    Rolfe, S. T. andBarsom, J. M., Fracture and Fatigue Control in Stractures, Prentice-Hall, Englewood Cliffs, NJ (1977).Google Scholar
  5. 5.
    Sih, G. C., Paris, P. C. andIrwin, G. R., “On Cracks in Rectillinearly Anistropic Bodies,”Int. J. Frac. Mech.,1 (3),189–203 (1965).Google Scholar
  6. 6.
    Wu, E. M., “Discontinuous Mode of Crack Extension in Unidirectonal Composites,” TAM Rep. No. 309, Univ. of Illinois (1968).Google Scholar
  7. 7.
    Wu, E. M. and Reuter, R. C., “Crack Extension in Fiberglass Reinforced Plastics,” TAM Rep. No. 275, Univ. of Illinois (1965).Google Scholar
  8. 8.
    Delale, F., Bakirtas, I. andErdogan, F., “The Problem of an Inclined Crack in an Orthotropic Strip,”J. Appl. Mech.,46 (1),90–96 (March1979).Google Scholar
  9. 9.
    Sih, G. C., “Fracture Mechanics of Composite Materials,” Frac. of Com. Mat., ed. Sih and Tamuzs, Sijhoff and Noordhoff, 111 (1979).Google Scholar
  10. 10.
    Barnet, D. M. andAsaro, R. J., “The Fracture Mechanics of Slit-Like Cracks in Anisotropic Elastic Media,”J. Mech. and Phys. of Solids,20,353–366 (1972).Google Scholar
  11. 11.
    Daniel, I. M., Niiro, M. andKoller, G. M., “Development of Orthotropic Birefringent Materials for Photoelastic Stress Analysis,”IITRI Project No. M6044, IIT Res. Inst., Chicago, IL (May1981).Google Scholar
  12. 12.
    Voloshin, A. S. andBurger, C. P., “Half-Fringe Photoelasticity: A New Approach to Whole-Field Stress Analysis,”Experimental mechanics,23 (3),304–313 (Sept.1983).CrossRefGoogle Scholar
  13. 13.
    Burger, C. P. and Voloshin, A. S., “A New Instrument for Whole Field Stress Analysis,” presented at 28th Int. Instr. Symp., ISA, Las Vegas (May 2–6, 1982).Google Scholar
  14. 14.
    Coren, H. T., “Fracture Mechanics of Composites,”Fracture,VII,Academic Press,New York, NY (1972).Google Scholar
  15. 15.
    Irwin, G. R., “Analytical Aspects of Crack Stress Field Problems,” TAM Rep. No. 213, Univ. of Illinois (1962).Google Scholar
  16. 16.
    Wu, E. M., “Application of Fracture Mechanics to Orthotropic Plates,” TAM Rep. No. 248, Univ. of Illinois (1963).Google Scholar
  17. 17.
    Westergaard, H. M., J. Appl. Mech.,6,A49-A53 (June1939).Google Scholar
  18. 18.
    Sampson, R. C., “A Stress-Optic Law for Photoelastic Analysis of Orthotropic Composites,”Experimental Mechanics,10, (5),210–215 (May1970).CrossRefGoogle Scholar
  19. 19.
    Hyer, M. W. and Liu, D., “An Assessment of the Accuracy of Orthotropic Photoelasticity,” Proc. 1983 SESA Spring Mtg. (May 1983).Google Scholar
  20. 20.
    Dally, J. W. andPrabhakaran, R., “Photo-Orthotropic-Elasticity,”Experimental Mechanics,11,346–356 (1971).Google Scholar
  21. 21.
    Prabhakaran, R. andDally, J. W., “Photo-Orthotropic Elasticity,”J. Strain Anal.,7 (4),253–260 (1972).Google Scholar
  22. 22.
    Prabhakaran, R., “Photoelastic Analysis of an Orthotropic Ring Under Diametral Compression,”AIAA J.,11 (6),777–778 (June1973).Google Scholar
  23. 23.
    Pipes, R. B. andDally, J. W., “On Fiber-Reinforced Birefringent Composite Materials,”Experimental Mechanics,13 (8),348–349 (1973).Google Scholar
  24. 24.
    Prabhakaran, R., “Strain-Optic Law for Orthotropic Model Materials,”AIAA J.,13 (6),723–728 (1975).Google Scholar
  25. 25.
    Cernosek, J., “On Photoelastic Response of Composites,”Experimental Mechanics,15 (9),354–357 (1975).CrossRefGoogle Scholar
  26. 26.
    Prabhakaran, R., “The Interpretation of Isoclinics in Photo-Orthotropic-Elasticity,”Experimental Mechanics,16, (1),6–10 (1976).CrossRefGoogle Scholar
  27. 27.
    Zachary, L. W. and Mojtahed, M., “Isochromatic Fringe Patterns for Cracks in Orthotropic Materials,” 12th Southwestern Conf. on Theo. and Appl. Mech., Pine Mountain, GA (May 1984).Google Scholar
  28. 28.
    Mojtahed, M., “Application of Photoelasticity oto Determine Mode One and Mode Two Orthotropic Stress Intensity Factors,”PhD dis., Iowa State Univ., Ames, IA (1984).Google Scholar
  29. 29.
    Voloshin, A. S. and Burger, C. P., “Photo-Orthotropic Elasticity Through a Digital Image Analysis of Low Level Birefringence,” 7th Int. Conf. on Exp. Stress Anal., Haifa, Israel (Aug. 23–27, 1982).Google Scholar
  30. 30.
    Miskioglu, I., Voloshin, A. S. and Burger, C. P., “Evaluation of Stress Intensity Factors Using Half-Fringe Photoelasticity” (abstracts), 19th Ann. Mtg. Soc. Eng. Sci, Rolla, MO (1982).Google Scholar
  31. 31.
    Kar, R., “Stress Intensity Factors (SIF) in Glass Plates with Edge Cracks by Half Fringe Photoelasticity,”MS thesis, Iowa State Univ., Ames, IA (1982).Google Scholar
  32. 32.
    Sanford, R. J. andDally, J. W., “Stress Intensity Factors in the 3rd Stage Fan Disk of the TF-30 Turbine Engine,”Eng. Frac. Mech.,11 (9),621–633 (1979).Google Scholar

Copyright information

© Society for Experimental Mechanics, Inc. 1987

Authors and Affiliations

  • M. Mojtahed
    • 1
  • L. W. Zachary
    • 1
  1. 1.Department of Engineering Science & Mechanics and Engineering Research Institute, ESM 3020Iowa State UniversityAmes

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