Experimental Mechanics

, Volume 4, Issue 6, pp 153–159 | Cite as

Isopachic patterns by the moiré method

Highly satisfactory correlation is found between results obtained with proposed method and those obtained by other experimental methods
  • Pericles S. Theocaris
Article

Abstract

Interference between a grating, with line rulings of a density of 500 lines/in., and its shadow is used for the determination of isopachics in plane-stress problems.

The procedure consists in using a white collimated light beam obliquely incident to the model. A reference master grating is attached to the surface of the model and the interference pattern of this grating and its shadow, produced by the oblique light beam, is photographed in a position normal to the model. Interference patterns before and after loading of the specimen allow the determination of isopachics.

Keywords

Mechanical Engineer Fluid Dynamics Light Beam Interference Pattern Line Ruling 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Bibliography

  1. 1.
    Theocaris, P. S., “Moiré Fringes: A Powerful Measuring Device,”Appl. Mech. Rev., 15 (5),333–339 (1962).Google Scholar
  2. 2.
    Favre, H., “Méthode Purement Optique de Détermination des Tensions Intérieures se produisant dans les Constructions,”Schweitzerische Bauzeitung, 90, 291–296 and 307–312. See also H. Favre, Doctoral Dissertation in the E.T.H. Zurich, 1929.Google Scholar
  3. 3.
    Fabry, C., “Sur une Nouvelle Méthode pour l'Etude Expérimentale des Tensions Elastiques,”Comptes Rendus, Academie des Sciences, Paris, 190, 457–459 (1930).Google Scholar
  4. 4.
    Tesar, V., “Photoélasticité, Méthode purement optique pour Déterminer les Déformations d'Epaisseurs des Modèles,”Revue d'optique, 11, 97–104 (1932).Google Scholar
  5. 5.
    Frocht, M. M., “On the Optical Determination of Isopachic Stress Patterns,” Proceedings, Fifth International Congress for Applied Mechanics, 221–227, Cambridge, 1938.Google Scholar
  6. 6.
    Sinclair, D., “A New Optical Method for the Determination of the Principal Stress Sum,” Proceedings of the Tenth Semi-Annual Eastern Photoelasticity Conference, 43–47, December 1939. See also D. Sinclair, “Interferometer Method of Plane Stress Analysis,” Jnl. Opt. Soc. Am., 30, 511–516 (1940).Google Scholar
  7. 7.
    Bubb, F. W., “A Complete Photoelastic Instrument,”Ibid.,,30 (7),297–298 (July 1940).Google Scholar
  8. 8.
    Dose, A., andLandwehr, R., “Zur Bestimmung der Isopachen in der Spannungsoptik,”Naturwissenschaften, 36, 342–346 (1949).Google Scholar
  9. 9.
    Mesmer, G., “The Interference Screen Method for Isopachic Patterns,”Proc. SESA, XIII (2),21–26 (1956).Google Scholar
  10. 10.
    Drouven, G., “Measurement of the Sum of the Principal Stresses in Plane Problems of Elasticity by Interference,”Doctoral Dissertation, Washington University, Saint Louis, Mo., 1952.Google Scholar
  11. 11.
    Post, D., “Photoelastic Stress Analysis for an Edge Crack in a Tensile Field,”Proc. SESA, XII (1),99–116 (1954).Google Scholar
  12. 12.
    Post, D., “A New Photoelastic Interferometer Suitable for Static and Dynamic Measurements,”Proc. SESA, XII (1),191–202 (1954).Google Scholar
  13. 13.
    Post, D., “Photoelastic Evaluation of Individual Principal Stresses by Large Field Absolute Retardation Measurements,”Proc. SESA, XIII (2),119–132 (1955).Google Scholar
  14. 14.
    Post, D., “Characteristics of the Series Interferometer,”Jnl. Opt. Soc. Am., 44 (3),243–249 (March 1954).Google Scholar
  15. 15.
    Frappier, E., “Etude d'un Interferomètre pour la Détermination des Lignes Isopachiques,”Analyse des Contraintes, Memoires du GAMAC, Tome II (8),29–36 (1957).Google Scholar
  16. 16.
    Pirard, A., “Consideration sur la Méthode du Moiré en Photoelasticité,”Analyse des Contraintes, Memoires du GAMAC, V (2),1–24 (1960).Google Scholar
  17. 17.
    Tolenaar, D., “Moiré Interferentie Verschijnselen bij Rasterdruk,”Amsterdam, Institut voor graphische Technick, 1945.Google Scholar
  18. 18.
    Dantu, P., “Utilisation des Réseaux pour l'Etude des Déformations,” Laboratoire Central des Ponts et Chaussees, Paris, Publ. No. 67-6, 1957.Google Scholar
  19. 19.
    Theocaris, P. S., “Moiré Method in Plates,” paper presented at the Colloquium of the International Association for Shell Structures, Warsaw, 1963.Google Scholar
  20. 20.
    Theocaris, P. S., “An Experimental Method for the Solution of Elastic-Plastic Plane-Stress Problems,”Jnl. Appl. Mech., 29, Trans. ASME 84, Series E, 735–743 (1962).See also P. S. Theocaris, “Diffused Light Interferometry for Measurement of Isopachics,” Jnl. Mech. Phys. Solids, 11 (3), 181–195 (1963).Google Scholar

Copyright information

© Society for Experimental Mechanics, Inc. 1964

Authors and Affiliations

  • Pericles S. Theocaris
    • 1
  1. 1.Laboratory for Testing MaterialsAthens National Technical UniversityAthensGreece

Personalised recommendations