Journal ArticleDOI
Some aspects of the optical techniques for strain determination
TLDR
In this article, a comparison of different optical methods where either photoelastic models, opaque bodies with transparent coatings or noncontacted objects are examined with coherent light is made, and some common features are contained by the three groups.Abstract:
In a general view, a comparison is made of different optical methods where either photoelastic models, opaque bodies with transparent coatings or noncontacted objects are examined with coherent light. Further, it is tried to show that some common features are contained by the three groups. These aspects concern the separation, by controlled determination, of displacement, rotation and strain (or of certain of their components), the multiplication of the optical effects in the detection and the elimination of secondary influences. In particular, the noncontacting method of wavefront reconstruction with double-exposure holograms is discussed and the role of the localization condition for the fringes in space is analyzed. On the other hand, it is illustrated that, besides the generally known birefringence and diffraction. use could be made of nonorthodox effects like rotation of the plane of polarization, second-harmonic generation in nonlinear optics, etc. This may, for instance, contribute to the optical instrumentation when transparent models and bodies with photoelastic coatings are investigated under the above aspects.read more
Citations
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Book ChapterDOI
I Heterodyne Holographic Interferometry
TL;DR: Holographic interferometry has some unique properties, which makes it superior to classical interferomet; wavefields from the same object, but under different conditions and at different times, can be compared.
Journal ArticleDOI
Homogeneous deformations: determination by fringe vectors in hologram interferometry.
TL;DR: When an object undergoes a combination of minute rigid-body motion and homogeneous deformation, its vectorial displacements can be described by a general, 3 x 3 matrix transformation and this same matrix can be used to transform the sensitivity vector of hologram interferometry into a fringe vector that defines the fringes as laminae that are intersected by the surface of the object.
Book ChapterDOI
Quantitative Determination of Displacements and Strains from Holograms
TL;DR: In this paper, procedures for quantitative determination of displacements and strains directly from holograms are presented, and the fringe-vector method, relating the holographically determined strains and rotations to the object surface via the projection matrices based on the object's local surface normals, is outlined.
Journal ArticleDOI
Sur la Détermination Holographique de L'état de Déformation à la Surface D'un Corps Non-transparent
M. Dubas,Walter Schumann +1 more
TL;DR: In this paper, les franges presentent des proprietes interessantes, en particulier celle de n'etre visibles qu'en certains endroits seulement, c'est-a-dire d'etres localisees.
Journal ArticleDOI
Theory of speckle displacement and decorrelation and its application in mechanics
TL;DR: In this paper, the authors deal with the determination of tensors of an elementary area of an object surface by means of an optical experimental method, which makes use of properties of the speckle field in an optically free space or in an image field.
References
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Journal ArticleDOI
Interferometric Vibration Analysis by Wavefront Reconstruction
Robert L Powell,Karl A. Stetson +1 more
TL;DR: In this paper, a study of the Leith-Upatnieks hologram for the time average of the coherent wavefronts scattered from a vibrating object is reported, and the image reconstructed by the hologram is found to contain a system of interference fringes which map contours of constant vibration amplitude, thus providing a method of analyzing the vibration of objects with arbitrary surfaces.
Journal ArticleDOI
Interferometric displacement measurement on scattering surfaces utilizing speckle effect
TL;DR: In this article, the distribution of intensity in the resultant pattern depends on the relative phases of the component patterns, and by measuring the correlation between the resultant patterns at two different times a change of relative phase is detected.
Journal ArticleDOI
Surface-deformation measurement using the wavefront reconstruction technique.
K. A. Haines,B. P. Hildebrand +1 more
TL;DR: A new method for the measurement of minute deformations of arbitrary three-dimensional objects, such as might occur due to applied stress, as well as the interpretation of the interference phenomena observed in terms of the translations and rotations undergone by a point on the object.
Journal ArticleDOI
Holographic interferometry applied to measurements of small static displacements of diffusely reflecting surfaces
TL;DR: It is shown how a single hologram method of analysis, utilizing parallax and fringe counting, and a multiple holographic interferometry method, using interference order assignment are related.
Journal ArticleDOI
Measurement of in-plane surface strain by hologram interferometry
TL;DR: In this article, it was shown that the interference fringe patterns obtained by hologram interferometry provide information about surface displacement resolved in one direction only, by recording holograms of the surface from different viewpoints and operating numerically upon the fringe order numbers at corresponding points on the surface.
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