Journal ArticleDOI
Detection of defects in plates and diaphragms using a split-lens speckle-shearing interferometer
TLDR
In this paper, a speckle-shearing interferometer was used to examine diaphragms and plates with a split lens both for imaging and shearing functions, and it was found that the location, shape and size of the defect could be ascertained accurately under certain conditions.Abstract:
Diaphragms and plates were examined with a speckle-shearing interferometer which utilized a split lens both for imaging and shearing functions. It was found that the location, shape and size of the defect could be ascertained accurately under certain conditions. The experiments showed that the fringe pattern of a defective diaphragm under pressure loading could be simulated on a good diaphragm by subjecting it to a combined loading (pressure and a concentrated load) with the proper shear orientation. However, in extreme situations — not likely to occur in practice — a defect could behave as a mini diaphragm with an elastic boundary. Lens aberrations degraded the contrast of slope fringes considerably.read more
Citations
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Journal ArticleDOI
Use of holographic optical elements in speckle metrology: part 2.
Chandra Shakher,G. Venkata Rao +1 more
TL;DR: Theoretical analysis and experimental investigations reveal that an almost diffraction-limited performance in speckle metrology can be achieved over the entire object field that can be imaged by this hololens configuration.
Journal ArticleDOI
Speckle shear interferometry
TL;DR: In this article, a number of speckle shear methods and their applications to ndt are discussed and experiments using multiple apertures with custom-made optical elements have shown that in-plane displacement, slope and curvature patterns can be obtained by filtering through appropriate haloes.
Dissertation
Analysis of error functions in speckle shearing interferometry
Wan Abdullah,Wan Saffiey. +1 more
TL;DR: In this article, a quantified maximum phase change difference analysis for derivative out-of-plane and in-plane (OOP) cases that propagate from the divergence of illumination wavefront compared to collimated illumination is presented.
References
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Book
Theory of plates and shells
TL;DR: In this article, the authors describe the bending of long RECTANGULAR PLATES to a cycloidal surface, and the resulting deformation of shels without bending the plates.
Journal ArticleDOI
Strain analysis by one-beam laser speckle interferometry. 2: Multiaperture method.
F. D. Chiang,R. P. Khetan +1 more
TL;DR: It is shown that the basic fringe-forming mechanism is no different from that of single-aperture recording, except that at the Fourier filtering stage the diffracted light energy is concentrated at the spatial frequencies admitted by the apertures.
Journal ArticleDOI
Sandwich hologram interferometry. 2: some practical calculations.
TL;DR: Four dimensionless equations have been found that can be used for fringe evaluation by measuring sandwich motions and can directly reveal signs of displacements and maximal object strain in this new analogous compensating method.
Journal ArticleDOI
Speckle shearing interferometry: a new method
TL;DR: The main methods of speckle shear interferometry include Michelson's interferometric arrangement, two or multiple apertures in conjunction with a lens and defocusing, and use of parallel plates and wedges in front of the lens with or without aperture.