Abstract
The three fundamental optical phenomena of diffraction, two-beam interference, and transformation by a lens form the basis of modern moiré strain-measurement techniques. The improved understanding of diffraction by superimposed gratings and optical spatial filtering leads to a general gain of freedom in designing moiré experiments. Benefits characteristic of refined but very simple optical-data-processing techniques include simpler apparatus, less-demanding procedure, possible large gains in sensitivity, and the ability to choose certain moiré parameters, such as sensitivity,after an experiment is concluded and the raw data stored. Sample results from a study of strains near cold-worked holes demonstrate that acceptable results can be had with elementary apparatus and systematic exploitation of optical-data processing.
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Cloud, G.L. Simple optical processing of moiré-grating photographs. Experimental Mechanics 20, 265–272 (1980). https://doi.org/10.1007/BF02328410
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DOI: https://doi.org/10.1007/BF02328410