Abstract
A double-exposure moiré-interferometry technique for topographic contour measurement of an arbitrarily curved object is presented. A curved surface coated with light-sensitive material is exposed twice in a volume of virtual gratings formed by the interference of two coherent light beams split from a laser. An adequate rotation of the curved surface relative to the virtual grating between the two exposures produces moiré fringes which reveal topographic contour, or contour under some conditions, of the surface. The advantage of the present method in comparison with others is that it offers both reasonably good fringe quality and easily adjustable high sensitivity. The sensitivity of the technique is shown to be from the order of micrometer to that of millimeter depending on the frequency of the virtual grating and the amount of the relative rotation. This technique was successfully applied to the topographic contour measurement of a cylindrical shell with and without a diametrical point loading.
The principle of this paper and some early results were presented at the SPIE conference held at Dearborn, MI on June 27–30, 1988 and appeared in its proceeding.1
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Dai, Y.Z. andChiang, F.P., “Moiré Interferometry Applied to Topographic Contour Measurement,”Proc. SPIE,954,153–159 (1988).
Meadows, D.W., Johnson, W.O. andAllen, J.B., “Generation of Surface Contours by Moiré Patterns,”Appl. Opt.,9 (4),942–947 (1970).
Takasaki, H., “Motré Topography,”Appl. Opt.,9 (6),1467–1472 (1970).
Khetan, R.P., “Theory and Application of Projection Moiré Methods,” PhD Thesis, State University of New York at Stony Brook (1975).
Hildebrand, B.P. andHaines, K.A., “Multiple-Wavelength and Multiple-Source Holography Applied to Contour Generation,”J. Opt. Soc. of Amer.,57 (2),155–162 (1967).
Jaisingh, G.K. andChiang, F.P., “Contouring by Laser Speckle,”Appl. Opt.,20 (19),3385–3387 (1981).
Post, D., “Development in Moiré Interferometry,”Opt. Eng.,21 (3),458–467 (1982).
Basehore, M.L. andPost, D., “Moiré Method for In-plane and Out-of-plane Displacement Measurement,”Experimental Mechanics,21 (9),321–328 (1981).
Beranek, W.J. andBruinsma, A.J.A., “Determination of Displacement and Strain Fields Using Dual-beam Holographic-moiré Interferometry,”Experimental Mechanics,20 (9),317–323 (1982).
Chiang, F.P., “Moiré Methods of Strain Analysis,” Manual on Experimental Stress Analysis, Third Edition, Chapt. 6, SESA, 51–69 (1979).
Chiang, F.P., Juang, R.M. andDai, Y.Z., “Application of Moiré and Speckle Techniques to Curved Surfaces Using a Periphery Camera,”Proc. SPIE,814,249–256 (1987).
Anastasi, R.F., Dai, Y.Z. andChiang, F.P., “Simplified Procedure for Obtaining High-Frequency, Highly Reflective Specimen Gratings for Moiré Interferometry,”Experimental Techniques,12 (9),16–17 (1988).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dai, Y.Z., Chiang, F.P. Contouring by moiré interferometry. Experimental Mechanics 31, 76–81 (1991). https://doi.org/10.1007/BF02325728
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02325728