Abstract
A new method for determining fringe order and the principal direction of birefringence from a single image combining an elliptically polarized white light and color image processing for practical photoviscoelastic analysis is developed. To determine fringe order, a data-base-search approach based on the primary color analysis is employed. After determining fringe order, the principal direction of birefringence is obtained by solving a non-linear equation. The successful applications of the method to photoelastic and photoviscoelastic analyses are shown. It is emphasized that the proposed method can be applicable to time-varying phenomena since multiple exposures are not necessary for sufficient data acquisition to complete stress analysis.
