Image Correlation Applied to Single Crystal Plasticity Experiments and Comparison to Strain Gage Data [electronic resource].
- Washington, D.C. : United States. Dept. of Energy, 2005. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- PDF-file: 12 pages; size: 1 Mbytes
- Additional Creators:
- Lawrence Berkeley National Laboratory, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
- Full-field optical techniques are becoming increasingly popular for measuring the deformation of materials, especially in materials that exhibit non-uniform behavior. While there are many full-field techniques available (e.g. moire interferometry, electronic speckle pattern interferometry (ESPI), holography, and image correlation ), for our study of the deformation of single crystals, the image correlation technique was chosen for its insensitivity to vibrations and ability to measure large strains. While the theory and development of the algorithms for image correlation have been presented elsewhere [2,3] a comparative study to a conventional strain measurement device, such as a strain gage rosette, is desired to test the robustness and accuracy of the technique. The 6 Degrees of Freedom (6DOF) experiment, which was specifically designed to validate dislocation dynamics (DD) simulations , is ideally suited to compare the two methods. This experiment is different from previous experiments on single crystals in that it allows the crystal to deform essentially unconstrained, in both the elastic and plastic regimes, by allowing the bottom of the sample to move as the sample is being compressed. This unconstrained motion prevents the internal crystal planes from rotating during the deformation as typically seen in the pioneering work of Schmid  and Taylor . In the early development of the 6DOF apparatus, stacked strain gage rosettes were used to provide the strain data . While very accurate at small strains, strain gages provide an averaged measurement over a small area and cannot be used to measure the inhomogeneous plastic strains that typically occur during the 6DOF experiment. An image correlation technique can measure the full-field in-plane and out-of-plane deformation that occurs in single crystals, and a comparison to the strain gage data at small strains can test the accuracy of the method.
- Published through SciTech Connect., 06/29/2005., "ucrl-jrnl-213561", Experimental Techniques, vol. 30, no. 4, July 31, 2006, pp. 33-37 FT, and Schmidt, T; Lassila, D H; LeBlanc, M M; Florando, J N; Tyson II, J.
- Funding Information:
View MARC record | catkey: 14105676