TY - GEN
T1 - Simultaneous observation of phase-stepped photoelastic images using diffraction gratings
AU - Kramer, Sharlotte
AU - Beiermann, Brett
AU - White, Scott
AU - Sottos, Nancy
PY - 2013
Y1 - 2013
N2 - 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.
AB - 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.
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U2 - 10.1007/978-1-4614-4235-6_45
DO - 10.1007/978-1-4614-4235-6_45
M3 - Conference contribution
AN - SCOPUS:84869782310
SN - 9781461442349
T3 - Conference Proceedings of the Society for Experimental Mechanics Series
SP - 327
EP - 332
BT - Imaging Methods for Novel Materials and Challenging Applications - Proceedings of the 2012 Annual Conference on Experimental and Applied Mechanics
T2 - 2012 Annual Conference on Experimental and Applied Mechanics
Y2 - 11 June 2012 through 14 June 2012
ER -