ISSN: 0090-3973
Published Online: 4 February 2008
Page Count: 5

Sawblade Vibration Mode Shape Measurement Using ESPI
Schajer, Gary S.
University of British Columbia, Department Mechanical Engineering,

Steinzig, Michael
Technical Bias, NM

(Received 24 August 2007; accepted 12 December 2007)

Abstract

Electronic Speckle Pattern Interferometry (ESPI) is used to measure the vibration mode shapes of circular and bandsaws. A video camera views a vibrating sawblade that is illuminated by a laser light. The image within the camera is mixed with a reference light to create an interference pattern. The reference phase is stepped by 180 degrees using a piezoelectric actuator before measuring each successive image. Subtraction of the successive images gives a contour view of the vibration mode of the sawblade. The technique is noncontacting and displays vibration mode shapes in real-time. It has the advantage over the classical Chladni method because it avoids the need to spread a powder over the sawblade surface and because it can also identify low-frequency vibrations.

Keywords:
ESPI, speckle pattern, mode shape, sawblade, Chladni

Paper ID: JTE101415
DOI: 10.1520/JTE101415
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