Abstract
A new polariscope system involving two rotating optical elements and a digital camera for whole field fringe analysis allows automated data to be acquired quickly and efficiently. The developed phase measuring technique that uses eight images through a circular polariscope is presented for the digital measurement of isochromatics and isoclinics, respectively, from photoelastic fringes in a circular disk under diametric compression. Isochromatics can directly be obtained using wrapped isoclinic phases calculated by the arc tangent operator which is the four-quadrant operator from −π to π. It is not required to unwrap isoclinic phases for the calculations of isochromatics. Unwrapped isoclinics are directly determined from isochromatic parameters. Distributions of digitally determined isoclinics are in close agreement to manual measurements. The errors which would appear in unwrapping process of isoclinics can be avoided in the determination of isochromatics.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Voloshin, A. S. and Burger, C. P, 1983, “Halffringe Photoelasticity: A New Approach to Whole-field Stress Analysis,”Experimental Mechanics, Vo. 23, pp. 304–3l3.
Asundi, A, 1993, “Phase Shifting in Photoelasticity,”Experimental Techniques, Vol. 7, No. 1, pp. 19–23.
Baek, T. H., Kim, M. S. and Kim, S. I., 2000a, “Stress Analysis of a Curved Beam Plate by using Photoelastic Fringe Phase Shifting Technique,”Transactions of the Korean Society of Mechanical Engineers A, Vol. 24, No. 9, pp. 2313–2318.
Quiroga, J. A. and Gonzales-Cano, A., 1997, “Phase Measuring Algorithm for Extraction of Isochromatis of Photoelastic Fringe Patterns,”Applied Optics, Vo. 36, No. 2, pp. 8397–8402.
Baek, T. H. and Burger, C. P., 1991, “Accuracy Improvement Technique for Measuring Stress Intensity Factors in Photoelastic Experiment,”KSME International Journal, Vol. 5, No. 1, pp. 22–27.
Baek, T. H., Kim, M. S., Rhee, J. and Rowlands, R. E., 2000b, “Hybrid Stress Analysis of Perforated Tensile Plates using Multiplied and Sharpened Photoelastic Data and Complex-Variable Techniques,”JSME International Journal, Series A: Solid Mechanics and Material Engineering, Vol. 43, No. 4, pp. 327–333.
Morimoto, Y., Morimoto, Y., Jr., and Hayashi, T., 1994, “Separation of Isochromatics and Isoclinics using Fourier Transform,”Experimental Techniques, pp. 13–17.
Theocaris, P. S. and Gdoutos, E. E., 1979,Matrix Theory of Photoelasticiry, Springer-Verlag, pp. 50–55.
Baek, T. H., Kim, M. S. and Cho, S. H., 2001, “Simulation of Separating Isoclinics and Isochromatics from Photoelastic Fringes of a Disk using 8-step Phase Shifting Methodology,”Journal of the Korean Society for Nondestructive Testing, Vol. 21, No. 2, pp. 189–196.
Ramesh, K. and Ganapathy, V., 1996, “Phase-shifting Methodologies in Photoelastic Analysis-The Application of Jones Calculus,”Journal of Strain Analysis, Vol. 31, No. 1, pp. 423–432.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Baek, T.H., Kim, M.S., Morimoto, Y. et al. Separation of isochromatics and isoclinics from photoelastic fringes in a circular disk by phase measuring technique. KSME International Journal 16, 175–181 (2002). https://doi.org/10.1007/BF03185168
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF03185168