Browse > Article
http://dx.doi.org/10.3807/KJOP.2005.16.3.239

Measurements of Inner Defects of the Plate using Dual-beam Shearography  

Ham, Hyo-Shick (Department of Physics, University of Incheon)
Choi, Sung-Eul (Department of Physics, University of Incheon)
Publication Information
Korean Journal of Optics and Photonics / v.16, no.3, 2005 , pp. 239-247 More about this Journal
Abstract
In this study, we have used newly developed dual-beam shearography which is based on laser speckle that includes various information about an object. Among the several shearing techniques, we used Michelson shearing interference technique which is the most powerful. Acrylate plate was used as a sample, which has inner defects and low thermal conductivity. Michelson shearing interferometer was used for obtaining speckle fringes. We also used phase shifting technique to get a phase map. Using single beam illumination, we could obtain mixture of deformation components of both in-plane and out-of-plane. In order to separate the two components, we have used dual-beam shearography technique. We have obtained a speckle pattern of both before and after deformation. Through LS filtering and unwrapping processes, we could find a position and a shape of the inner defects easily. Deformation of the acrylate plate due to thermal heating has occurred mainly in z-direction(out-of-plane) because it has low thermal conductivity. The acrylate plate was deformed only at the restricted area where the electrical heat applied.
Keywords
Dual-beam shearography; Michelson shearing interferometer; Inner defects; Phase map; LS filtering;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Y. Y. Hung and C. E. Taylor, 'speckle-shearing interferometric camera -- a tool for measurement of derivatives of surface displacement,' Proc. SPIE, vol. 41, pp. 169-175, 1973
2 R. S. Sirohi, C. J. Tay, H. M. Shang and W. P. Boo, 'Shear ESPI with small-objects,' Int. Coriference on Applied Optical Metrology, P. K. Rastogi, F. Gyimesi, Ed., Proc. of SPIE, vol. 3407, pp. 332-337, 1998   DOI
3 J. A. Leendertz and J. N. Butters, 'An image-shearing speckle pattern interferometer for measuring bending moments,' J. Phys. E6, pp. 1107-1110, 1973
4 Y. Y. Hung, 'Shearography : a novel and practical approach for nondestructive testing,' J. of Nondestructive Testing, vol. 8, no. 2, pp. 55-67, 1989
5 P. K. Rastogi 'Techniques of Displacement and Deformation Measurements in Speckle Metrology' Swiss Federal Institute of Technology, Lausanne, Switzerland, pp. 76, 1993
6 Y. Y. Hung and J. Q. Wang, 'Dual-beam Phase Shift Shearography for Measurement of In-plane Strains,' Optics and laser in Engineering, vol. 24, no. 5-6, pp. 403-413, 1996   DOI   ScienceOn
7 Y. Y. Hung, 'Shearography and Applications in Experimental Mechanics,' Proc. of SPIE, vol. 2921, pp. 2-28,1997   DOI
8 R. S. Sirohi, Speckle Metrology (Marcel Dekker Inc, New York, 1993), pp. 99-155
9 R. S. Sirohi, Speckle Metrology (Marcel Dekker Inc, New York, 1993), pp. 74-75
10 K. Patorski, A OIszak, Ed., 'Digital in-plane electronic speckle pattern shearing interferometry,' Optical Engineering, vol. 36, no. 7, pp. 2010-2015, 1997   DOI   ScienceOn
11 M. Owner-Petersen and P. D. Jensen, 'Computer-aided electronic speckle pattern interferometry(ESPI): Deformation analysis by fringe manipulation,' Non-Destr. Test(Int), vol. 21, no. 6, pp. 422, 1988
12 W. W. Macy, 'Two-dimensional fringe pattern analysis,' Applied Optics, vol. 22, pp. 3898, 1983   DOI