Topic
Moiré pattern
About: Moiré pattern is a research topic. Over the lifetime, 1917 publications have been published within this topic receiving 27176 citations. The topic is also known as: moiré fringes & moire pattern.
Papers published on a yearly basis
Papers
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TL;DR: In this article, a non-contact optical method based on the fringe projection technique was proposed for 3D shape measurement of a hydroformed shell by a CCD camera and a Fourier transform is performed on the image using a microcomputer.
18 citations
TL;DR: In this article, the authors determine the shear strain component by observing the rotation of the moire fringes in close proximity to the hole, and compared the results of experiments on a specimen containing a model residual stress distribution.
Abstract: The use of interferometric moire and hole drilling to determine residual stress has been well reported and accepted for stress fields whose principal directions can be predicted well enough to permit the moire grids to be aligned with the principal strain axes. When the principal strains do not align themselves with the grid axes, a third strain component can be obtained by working with the diagonal pitch of the moire grid, but this requires resetting the optical bench to the lower frequency. Diffraction efficiency is lost, with an additional loss in sensitivity. In this paper, the authors determine the shear strain component by observing the rotation of the moire fringes in close proximity to the hole. The results of experiments on a specimen containing a model residual stress distribution are presented and compared with the theoretical prediction. Finally, the isothetic contours, based on elastic theory, were computed and plotted for several cases to verify this proposition. These results and the expected residual stress distribution are also compared to the experimentally obtained moire fringes.
18 citations
Patent•
02 Jan 1985
TL;DR: In this article, a low-pass filter is used to adjust the low pass filter by replacement or displacement until the moire disappears on the lattice plane, and then the light rays from the color original are modulated by the selected lowpass filter.
Abstract: Methods and apparatus for avoiding moire occurring in color scanning for graphic art, wherein light rays from a color original are passed through a pick-up lens, and prior to starting the color scanning, are modulated by means of a low-pass filter, which modulated rays are branched into two optical paths, on one of the paths a lattice plane is provided so as to project the modulated rays thereon, the lattice plane being beforehand selected in accordance with various conditions for scanning. A possible moire on the lattice plane is observed thereby to adjust the low-pass filter by replacement or displacement until the moire disappears on the lattice plane. Finally the light rays from the color original are modulated by the selected low-pass filter.
18 citations
TL;DR: The simple formula derived in the paper establishes a direct relationship between moire beat patterns and basic grids for minute displacements and possible advantages of the practical use of this element are outlined.
Abstract: The simple formula derived in the paper establishes a direct relationship between moire beat patterns and basic grids for minute displacements. The possibilities of finding a basic grid for a desired moire pattern are pointed out. The analysis is illustrated by several examples of Fresnel moire zone plate patterns and concentric equidistant circular moire patterns obtained by changes of scale and rotation. Possible advantages of the practical use of this element are outlined.
17 citations
TL;DR: In this paper, a digital double exposure hologram is formed by addition of two digital holograms corresponding to two different stages of the object to give the intensity interferograms superimposed on the image of an object.
17 citations