Please use this identifier to cite or link to this item: https://doi.org/10.1117/12.468767
Title: Self-comparative holography and shearography
Authors: Shang, H.M. 
Keywords: Holography
Nondestructive testing
Shearography
Issue Date: 2001
Source: Shang, H.M. (2001). Self-comparative holography and shearography. Proceedings of SPIE - The International Society for Optical Engineering 4537 : 59-62. ScholarBank@NUS Repository. https://doi.org/10.1117/12.468767
Abstract: Double-exposure holography and double-exposure shearography are two interferometric techniques that are particularly useful for precision measurement, and for non-destructive inspection and evaluation of the structural integrity of test objects. Quite often, objects with symmetrical deformation are tested and the challenge to the engineer is to check for symmetry in the deformation. While the holographic and shearographic fringe patterns are able to achieve this, it is felt that the inspection process can be simplified and expedite considerably if the engineer needs only to look for either the absence or the presence of fringes. In other words, a "go, no-go" gauging method is desired so that the absence of interference fringes depicts symmetrical deformation and the presence of interference fringes depicts asymmetrical deformation. This paper demonstrates that this gauging method can be realized with the use of a commercial beam-splitting cube. By carefully orientating the beam-splitting cube, the image of the test object is brought to overlap, either fully or partially, with the mirror-image of the test object. With fully overlapping images, the relative displacement between two symmetrically located points on the test surface is obtained, resulting in the technique of self-comparative holography. This method is found useful in checking the symmetrically of deformation. With partially overlapping images, the relative displacement-derivative between two symmetrically located points on the test surface is obtained, resulting in the technique of self-comparative shearography.
Source Title: Proceedings of SPIE - The International Society for Optical Engineering
URI: http://scholarbank.nus.edu.sg/handle/10635/73832
ISSN: 0277786X
DOI: 10.1117/12.468767
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

SCOPUSTM   
Citations

1
checked on Dec 6, 2017

Page view(s)

18
checked on Dec 10, 2017

Google ScholarTM

Check

Altmetric


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.