Abstract
Two computer-aided methods have been developed for analysis of in-plane and out-of-plane surface displacements of structures under load. Both methods are whole-field techniques which combine phase-stepped geometric moire with video and computer technologies. With these methods, a displacement field of interest is determined by computer-processing phase stepped, geometric moiré image data with fringe ordering done automatically within the software. The theory of the techniques is described and results of accuracy tests and application problems are given. It is shown that very good agreement is obtained between theory and experiment for in-plane strain determinations. For out-of-plane displacement determinations errors are only a few percent over the entire field of view. The application problems discussed are: (1) the measurement of composite column buckling, and (2) the determination of the shape of a slightly distorted, thin aluminum plate.
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Sullivan, J.L. Phase-stepped fractional moiré. Experimental Mechanics 31, 373–381 (1991). https://doi.org/10.1007/BF02325996
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DOI: https://doi.org/10.1007/BF02325996