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Topic

Moiré pattern

About: Moiré pattern is a(n) research topic. Over the lifetime, 1917 publication(s) have been published within this topic receiving 27176 citation(s). The topic is also known as: moiré fringes & moire pattern.


Papers
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Journal ArticleDOI
Abstract: A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

3,417 citations

Journal ArticleDOI
TL;DR: A new computer-based technique for automatic 3-D shape measurement is proposed and verified by experiments that has a much higher sensitivity than the conventional moire technique and is capable of fully automatic distinction between a depression and an elevation on the object surface.
Abstract: A new computer-based technique for automatic 3-D shape measurement is proposed and verified by experiments. In contrast to the moire contouring technique, a grating pattern projected onto the object surface is Fourier-transformed and processed in its spatial frequency domain as well as in its space-signal domain. This technique has a much higher sensitivity than the conventional moire technique and is capable of fully automatic distinction between a depression and an elevation on the object surface. There is no requirement for assigning fringe orders and interpolating data in the regions between contour fringes. The technique is free from errors caused by spurious moire fringes generated by the higher harmonic components of the grating pattern.

1,726 citations

Journal ArticleDOI
Abstract: An x-ray interferometer has been developed that uses two transmission phase gratings to analyze wave front distortions in the hard x-ray range. The interferometer is insensitive to mechanical drift and vibrations, and it is tunable over a wide range of photon energies. This setup was used for differential phase contrast imaging of low-absorbing test objects. We obtained micrographs with moire fringes of good visibility, which revealed the local phase shift gradient caused by the objects. A comparison with numerically simulated images indicates that quantitative analysis of unknown phase objects is possible.

598 citations

Journal ArticleDOI
TL;DR: It is shown that moiré contour patterns provide a useful and flexible means of contouring surfaces.
Abstract: For a number of years, observations have been made of contour-like patterns created by the moire interference of a grid with its shadow cast onto a surface. The conditions under which these patterns correspond to planar contours are derived, and systems to generate these contours are suggested. It is shown that moire contour patterns provide a useful and flexible means of contouring surfaces. Experimental results are presented.

492 citations

Book
13 Jun 1995
Abstract: Moire patterns (which form when two regular patterns of comparable frequency interfere) are sensitive indicators of changes of shape as objects rotate, heat up, or are otherwise affected by external forces Applications include non-destructive testing and evaluation, and quality and process control This text explains the theory and practice of physical measurements by high-sensitivity moire - principally moire interferometry, focusing on the mechanics and micromechanics of materials and structural elements Moire interferometry is unique in providing maps of in-plane displacements from which can be derived normal and shear strains Typical moire sensitivities are on the order of 2-4 fringes per fm displacement, but sensitivities of 17 nm per fringe contour can be reached The applications discussed include: advanced composite materials, thermal stresses, electronic packaging, fracture, metallurgy, time-dependence, and strain gage calibration The methods discussed in the text can be applied for whole-field measurements on nearly solid and solid bodies

485 citations

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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20221
202125
202048
201946
201844
201744