NEW OPTICAL SLICING WHOLE-FIELD METHOD IN 3-DIMENSIONAL PHOTOELASTICITY USING NUMERICAL ACQUISITION AND ANALYSIS OF THE SPECKLE FIELDS IN SCATTERED-LIGHT

The method presented allows the visualization of isochromatics and iso clinic fringes of an optically isolated slice, within a photoelastic m aterial. The basic idea is to delimit the slice between two plane lase r beams, and to use the interference possibilities of the diffused bea ms. The resulting image consists of a speckle pattern recorded by a CC D camera, and then numerically analysed. This technique is much simple r and faster than the one previously developed, using holographic film , polychromatic laser beam and optical filtering.