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Optical Engineering • Open Access

Traceable technique for an in situ full field in-plane measurement validation of digital image correlation

Paper Abstract

For digital image correlation to be firmly accepted as a validated displacement measurement system in the industrial arena, a measurement must be captured by the analysis system at time of test which confirms that the image correlation hardware and software system is performing as expected. To this end, a method for validating stereo digital image correlation optical test setups is presented, which is traceable to the length standard. The method employs a screen, on which is displayed a randomized speckle pattern of appropriate pitch for the test in question. This speckle pattern is then artificially translated by a known number of pixels on the screen, and image pairs captured of the original and translated speckles. Processing of these data image pairs with image correlation, and calibration of the pixel pitch of the display screen using a traceable measurement system, allows the image correlation test setup to be traceably calibrated in terms of in-plane displacement. The method is shown to be sufficiently sensitive and repeatable to provide a reasonably accurate, traceable validation in a practical environment.

Paper Details

Date Published: 2 March 2017
PDF: 8 pages
Opt. Eng. 56(3) 033101 doi: 10.1117/1.OE.56.3.033101
Published in: Optical Engineering Volume 56, Issue 3
Show Author Affiliations
Eszter Szigeti, Airbus Operations Ltd. (United Kingdom)
Matthew Loparco, Airbus Operations Ltd. (United Kingdom)
Evgeni Todorov, Airbus Operations Ltd. (United Kingdom)
Shelby Wheatley, Airbus Operations Ltd. (United Kingdom)
Richard John Greene, Strain Solutions Ltd (United Kingdom)

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