Conclusions
A simple and new approach for digital fringe multiplication of photoelastic image based on the image-division technique is described and demonstrated. By applying the trigonometric identities of different angle relations of cosine function, the fringes can be multiplied to various times. The factor to be multiplied is limited by the resolution of the image-processing system and the quantization errors. The linearity of the system was calibrated effectively using a standard density tablet and the polynomial regression method. This effort makes the following image-division operation more accurate. The use of a PC-based image-processing system eliminates the photographic process and optical equipment of the conventional methods of fringe multiplication.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Dally, J.W. and Riley, W.F., Experimental Stress Analysis, McGraw-Hill Book Co., (1978).
Post, D. “Isochromatic Fringe Sharpening and Fringe Multiplication in Photoelasticity,” Proc. SESA, XII (2), 143–157, (1955).
Talukder, N.K.D. and Ghosh, P., “On Fringe Multiplication by Superimposition of Negatives,” EXPERIMENTAL MECHANICS, 15(6), 237–239, (1975).
Dally, J.W. and Ahimaz, F.J., “Photographic Method to Sharpen and Double Isochromatic Fringes,” EXPERIMENTAL MECHANICS, 2(6), 170–175, (1962).
Bynum, D.J., “On the Accuracy of Fringe Multiplication with Mirrored Birefringent Coatings,” EXPERIMENTAL MECHANICS, 6(7), 381–382, (1966).
Toh, S.L., Tang, S.H. and Hovanesian, J.D., “Computerized Photoelastic Fringe Multiplication,” EXPERIMENTAL TECHNIQUES, 14(4), 21–23, (1990).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Chen, T.Y. Digital fringe multiplication of photoelastic images—A new approach. Exp Tech 18, 15–18 (1994). https://doi.org/10.1111/j.1747-1567.1994.tb02379.x
Published:
Issue Date:
DOI: https://doi.org/10.1111/j.1747-1567.1994.tb02379.x