Skip to main content
Log in

Integrated-plane photoelastic method—Application of photoelastic isodynes

Paper presents basic theory and examples of application of a new photoelastic method developed to determine all components of a plane-stress field, including contact problems, by means of simple optical measurements only. This single-model, nondestructive and simple method uses a new type of scattered-light modulation, called a field of isodynes by the authors, which represents a generalization of the integrated method developed by Pindera and Straka

  • Published:
Experimental Mechanics Aims and scope Submit manuscript

Abstract

It has been shown by Pindera and Mazurkiewicz that a new type of scattered-light modulation in the plane of a two-dimensional photoelastic object can be obtained when the stationary integrated photoelastic method developed by Pindera and Straka is applied in a scanning mode and when the transfer function of the photoelastic system satisfies certain conditions. The new type of light modulation, called field of isodynes by the authors, carries information on stress components normal to the direction of propagation of primary beam, and on corresponding total-force component. The points where this stress component is equal to zero can be easily determined.

The classical scattered-light modulation along a chosen line represents a cross section of a corresponding isodynes field.

It is shown that these features of the method of isodynes make it possible to easily determine the distribution and values of normal stress components at any arbitrary rectilinear cross section, and to check immediately the accuracy of measurements. The experimental determination of contact stresses and contact regions using the method of isodynes is especially simple and elegant.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Abbreviations

σ:

stress

σ1, σ2, σ3 :

principal-stress components

σ '1 , σ '2 , σ '3 :

secondary principal-stress components

σx, σy, σz :

normal-stress components

α:

azimuth of isoclinics; angle between the direction of polarization and the closer principal direction

α s :

azimuth of electric vector of primary beam: angle between the electric vector and the principal-stress component σ s

γ:

azimuth of scattered beam with respect to σ s -direction

I to :

initial intensity of transmitted light

I so :

initial intensity of primary beam

k, K :

coefficients related to light attenuation

I t :

final intensity of transmitted light

I s ′, I s :

intensities of scattered light, in a general case and in optimal conditions, respectively

(I s ′) c ,(I s ) c :

intensities of complementary scattered beams

I s1 ,I s2 :

optimal intensities of the first-order scattered beam and the complementary scattered beam, respectively

R, ψ:

linear and phase retardation, respectively

R t,ψ :

linear and phase retardation, respectively, of the transmitted beam

R s ,ψ s :

linear and phase retardation, respectively, of the primary beam

Δψ:

additional retardation produced outside of specimen

m t ,m s :

normalized linear retardation of the transmitted and primary beam, respectively; order of isochromatics or of isodyne, respectively

m :

normalized linear retardation with respect to the corresponding wavelength of detecting radiation

λ:

wavelength of radiation; dominant wavelength

C σ ,C σ :

photoelastic coefficients and normalized photoelastic coefficient with respect to wavelength of light, respectively

S σ (λ, t), S σ ′(λ, t) :

model stress-optic coefficient, and material stress-optic coefficient for unit path length (1 cm), respectively, both dependent on the wavelength of detecting radiation and on the loading time

b :

thickness of specimen

s :

optical path

x, y, z :

Cartesian coordinates

S 1 :

first-order scattered beam

S 2 :

complementary scattered beam

S R :

reference scattered beam

P :

external force

dm/dS :

slope of the linear retardation curve along thes-path

t :

time

t o :

time of recording

T :

temperature

θ:

angle of observation: angle between the primary beam and the scattered beam carrying information

n :

principal index of refraction

n′ :

secondary index of refraction

References

  1. Pindera, J.T., “On the Transfer Properties of Photoelastic Systems,”Proceedings of the 7th All-Union Conference on Photoelasticity, Tallinn, Nov. 23–26, 1971.Akademia Nauk Estonskoi SSR. Tallin,1,48–63 (1971).

    Google Scholar 

  2. Pindera, J.T., “Response of Photoelastic Systems,”Trans. of the CSME,2,21–30 (1973-74).

    Google Scholar 

  3. Coker, E.G. and Filon, L.N.G., “A Treatise on Photo-Elasticity,” Cambridge University Press, First Edition (1931), Second Edition (1957).

  4. Frocht, M.M., Photoelasticity, J. Wiley, New York,1 (1946),2 (1948).

    Google Scholar 

  5. Föppl, L. andNeuber, H., “Festigkeitslehre mittels Spannungsoptik,”Verlag von R. Oldenbourg, Berlin (1935).

    Google Scholar 

  6. Vadovič, F., “New Method of Photoelastic Stress Separation by Means of Airy Function” (in Slovak),Stroino-Electrotechnicky Časopis, Slovenska Akadémia Vied, Bratislava,VII (2),83–94 (1956).

    Google Scholar 

  7. Plechata, R., “Determination of the Plane State of Stress by Means of the First Partial Derivatives of the Airy Function” (in German).ACTA TECHNICA. Czechoslovak Academy of Sciences,6,526–552 (1960).

    Google Scholar 

  8. Tesař, V., “Representation simple et complète en grandeur et en direction des efforts intérieurs dans les problèmes d'élasticité plane.”Comptes-Rendus à l'Academie des Sciences, Paris (23 mars 1931).

    Google Scholar 

  9. Weller, R., “A New Method for Photoelasticity in Three Dimensions,”J. of Appl. Phys.,10 (4),266 (1939).

    Article  Google Scholar 

  10. Weller, R., “Three-Dimensional Photoelasticity Using Scattered Light,”J. Applied Physics,12,610–616 (1941).

    Article  Google Scholar 

  11. Jessop, H.T., “The scattered light method of exploration of stresses in two- and three-dimensional models,”British J. of Appl. Phys.,2,249–260 (1951).

    Google Scholar 

  12. Bokstein, M.F., “Investigations of Stresses by Using Scattered Light” (in Russian).Paper in book “Method of Stress Analysis Using Polarized Light”,edited by N.I. Prigorovski, Academy of Sciences SSSR, Moskova (1956).

    Google Scholar 

  13. Srinath, L.S., Frocht, M.M., “Scattered Light in Photoelasticity-Basic Equipment and Technique,”Proc. of the Fourth U.S. Natl Congr. of Appl. Mech.,2,775–781 (1962).

    Google Scholar 

  14. Hemann, J.H. andBecherer, R.J., “A Study of the Scattered-light Technique in Two-dimensional Problems,”Experimental Mechanics,12 (2),43–46 (1972).

    Google Scholar 

  15. Brillaud, H. and Lagarde, A., “Punctual determination of stress deviator in three-dimensional photoelasticity, Proc. of the 14th Cong of I.U.T.A.M., Delft (Sept. 1976).

  16. Robert, A. andGuillemet, E., “New Scattered Light Method in Three-Dimensional Photoelasticity,”British J. of Appl. Phys.,15,567–578 (1964).

    Google Scholar 

  17. Robert, A., “Contribution à l'étude de la Polarimétrie et de la Photoelasticimétrie.” Université Paul Sabatier de Toulouse (1973).

  18. Robert, A. andRoyer, J., “Principle de mesure des biréfringences a l'intérieur d'un solide transparent en vue de son application à la photoélasticimétrie tridimensionnelle,”C.R.Ac.Sc., Paris, t. 281, Série B (27 Oct.1975).

    Google Scholar 

  19. Lagarde, A., Oheix, P. andBrillaud, H., “Determination of the birefringence and rotatory power characterizing a thick medium. Applications in photoelasticity,”Mechanics Research Communications,3,107–112 (1976).

    Article  Google Scholar 

  20. Brillaud, J. andLagarde, A., “Mesure des formes de lumière en diffusion et applications,”C.R.Ac.Sc., Paris, t. 281, Série B (20 Oct.1975).

    Google Scholar 

  21. Desailly, R. andLagarde, A., “Rectilinear and circular analysis of a plane slice optically isolated in a three-dimensional photoelastic model,”Mech. Res. Comm.,4 (2),99–107 (1977).

    Article  Google Scholar 

  22. Stüve, H. andHeise, U., “Experimental determination of the stresses in edge-loaded disks by the Wieghardt analogy” (in German).Die Bautechnik,53 (1),18–22 (Jan. 1976).

    Google Scholar 

  23. Pindera, J.T. andStraka, P., “Response of the Integrated Polariscope,”J. Strain Anal.,8,65–76 (1973).

    Google Scholar 

  24. Pindera, J.T. andStraka, P., “On physical measures of rheological responses of some materials in wide ranges of temperature and spectral frequency,”Rheologica Acta,13,846–859 (1974).

    Article  Google Scholar 

  25. Pindera, J.T. andSze, Y., “Response of Elastic Plates in Flat Contact,”Proc. of the Intl Symp. on Exp. Mech., University of Waterloo (June 12–16, 1972): Experimental Mechanics in Research and Development, Solid Mechanics Division, University of Waterloo, Study No. 9, Edited by J.T. Pindera, H.H.E. Leipholz, F.P.J. Rimrott, D.E. Grierson, University of Waterloo, Waterloo, Ontario, Canada, 617–635 (1973).

    Google Scholar 

  26. Pindera, J.T. andMazurkiewicz, S.B., “Photoelastic Isodynes: A New Type of Stress-Modulated Light Intensity Distribution,”Mech. Res. Comm.,4 (4),247–252 (1977).

    Article  Google Scholar 

  27. Pindera, J.T. and Mazurkiewicz, S.B., “Theory and Technique of Photoelastic Isodynes.” To be published.

  28. Hecker, F.W. and Pindera, J.T., “Influence of Stress Gradient on Direction of Light Propagation in Photoelastic Specimens,” Proc. of the 6th Intl Conf. on Exp. Stress Anal. (September 18–22, 1978), Munich, Federal Republic of Germany, VDI-Berichte No. 313, 745–754 (1978).

  29. Pindera, J.T., “Technique of Photoelastic Investigations of Plane Stress Fields,” (in Polish).Rozprawy Inzynierskie,3 (1),109–176,Polish Academy of Sciences, Warsaw (1955).

    Google Scholar 

  30. Pindera, J.T., Mazurkiewicz, S.B. and Khattab, M.A., “Stress Field in Circular Disk Loaded Along Diameter: Discrepancies Between Analytical and Experimental Results.” SESA-Paper No. CR-10, presented at the 1978 SESA Spring Meeting, Wichita, KA (May 14–19, 1978).

  31. Mesmer, G.K., “Vergleichende spannungsoptische Untersuchungen und Fliessversuche unter konzentriertem Druck,” Dissertation, University of Göttingen (Feb., 1929). Technische Mechanik und Thermodynamik,1 (1930).

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Mazurkiewicz, S.B., Pindera, J.T. Integrated-plane photoelastic method—Application of photoelastic isodynes. Experimental Mechanics 19, 225–234 (1979). https://doi.org/10.1007/BF02328651

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02328651

Keywords

Navigation