Simultaneous observation of phase-stepped photoelastic images using diffraction gratings

Sharlotte Kramer, Brett Beiermann, Scott R White, Nancy R Sottos

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Phase-stepped photoelasticity is a powerful method for full-field stress analysis, but sequential collection of the multiple required images limits the technique to static loading applications. In an effort to collect four phase-stepped images simultaneously with a single camera for transient loading applications, we have developed a system that utilizes diffraction gratings, which are for separation of coherent monochromatic laser light. Two adjacent, perpendicularly oriented, 1D Ronchi rulings that are placed after a transparent sample split the light into equal intensity beams for each diffraction order. The four beams that are diffracted once in the x direction and once in the y direction transmit through arrays of analyzing polariscope elements, with different combinations of fast-axis orientations for four phased-stepped images. The mirrors and imaging lenses in the system work in concert to focus each beam onto separate quadrants of the same CCD. We demonstrate the system for stress analysis of compressive loading of a Homalite-100 disk. We can utilize this system for photoelastic analysis of time-dependent materials and of dynamic events, when equipped with a high-speed camera.

Original languageEnglish (US)
Title of host publicationImaging Methods for Novel Materials and Challenging Applications - Proceedings of the 2012 Annual Conference on Experimental and Applied Mechanics
Pages327-332
Number of pages6
DOIs
StatePublished - Jan 1 2013
Event2012 Annual Conference on Experimental and Applied Mechanics - Costa Mesa, CA, United States
Duration: Jun 11 2012Jun 14 2012

Publication series

NameConference Proceedings of the Society for Experimental Mechanics Series
Volume3
ISSN (Print)2191-5644
ISSN (Electronic)2191-5652

Other

Other2012 Annual Conference on Experimental and Applied Mechanics
CountryUnited States
CityCosta Mesa, CA
Period6/11/126/14/12

ASJC Scopus subject areas

  • Engineering(all)
  • Computational Mechanics
  • Mechanical Engineering

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  • Cite this

    Kramer, S., Beiermann, B., White, S. R., & Sottos, N. R. (2013). Simultaneous observation of phase-stepped photoelastic images using diffraction gratings. In Imaging Methods for Novel Materials and Challenging Applications - Proceedings of the 2012 Annual Conference on Experimental and Applied Mechanics (pp. 327-332). (Conference Proceedings of the Society for Experimental Mechanics Series; Vol. 3). https://doi.org/10.1007/978-1-4614-4235-6_45