Determination of Elastic-Plastic Boundary by Speckle Pattern Correlation
An optical-numerical correlation technique has been developed for detecting the elastic-plastic boundary on the surface of a material which has undergone plastic deformation. Laser speckle pattern produced from a surface is measured before and after plastic deformation which produces a change in their cross correlation. The speckle images are recorded and processed using a computer based vision system. Experimental results obtained for aluminum alloys have demonstrated the high sensitivity of this method. A comparison with theoretical and finite element results is presented.
KeywordsCross Correlation Speckle Pattern Diffraction Image Computer Vision System Speckle Image
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