| US 7,487,685 B2 | ||
| Strain measurement method and device | ||
| Koichi Kobayashi, Tokyo (Japan) | ||
| Assigned to Kabushiki Kaisha, (Japan) | ||
| Filed on Aug. 31, 2006, as Appl. No. 11/513,934. | ||
| Claims priority of application No. 2005-253096 (JP), filed on Sep. 01, 2005. | ||
| Prior Publication US 2007/0044568 A1, Mar. 01, 2007 | ||
| Int. Cl. G01L 1/24 (2006.01) | ||
| U.S. Cl. 73—800 [356/35.5] | 18 Claims |
| 1. A strain measurement method for a test piece for determining the Poisson's ratio of a test piece in real time comprising
the steps of:
irradiating the surface of a test piece with a laser beam for generating a spectral pattern;
viewing the changes in the spectral pattern with at least one CCD video camera as the test piece is placed under a tensile
force and tracking said test piece during the application of the tensile force such that the same area of said test piece
is being viewed by said at least one video camera;
coupling an image processor to said at least one video camera; and
coupling said image processor to a data processor for determine the Poisson ratio in real time as said test piece is placed
under a tensile force.
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