14 December 1988 Fast Detection Of Residual Stresses By Shearography
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Proceedings Volume 0955, Industrial Laser Interferometry II; (1988) https://doi.org/10.1117/12.947662
Event: SPIE International Symposium on Optical Engineering and Industrial Sensing for Advance Manufacturing Technologies, 1988, Dearborn, MI, United States
A modified shearographic (speckle-shearing) method for the rapid detection of residual stress in elastic engineering materials and components has been introduced. A coherent monochromatic light source (laser) is required to enable interference fringes to appear in the recording medium as a result of path length changes occurring between the two separate exposures during the evaluation. The path length change is a function of the objects surface displacement. The method employs a special image-shearing camera permitting quasi-full field measurement of surface displacement. A surface displacement, which occurs due to altering the specimen surface in the test area between the two exposures of a double exposure method, produces a fringe pattern which is visible using a high-pass Fourier filtering device. The viewed fringe pattern is directly related to stresses that are changed due to the surface alteration. The stresses altered are those present due to either a live-load or those resident in the specimen.
© (1988) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
M. Y. Y. Hung, M. Y. Y. Hung, K. W. Long, K. W. Long, X. Zhang, X. Zhang, J. D . Hovanesian, J. D . Hovanesian, R. Hathaway, R. Hathaway, "Fast Detection Of Residual Stresses By Shearography", Proc. SPIE 0955, Industrial Laser Interferometry II, (14 December 1988); doi: 10.1117/12.947662; https://doi.org/10.1117/12.947662


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