Abstract
A method was developed for determining the directions of the principal-stresses over an entire model from color photoelastic fringes obtained in a semicircular polariscope. The polariscope was composed of a circular polarizer and an ordinary liner polarizer. A model was illuminated with circularly polarized light and the light transmitted from the model was analyzed with only the rotation of analyzer so that phase-stepped color photoelastic fringes were obtained and the map of the principal-stress directions was later deduced from them. The effectiveness of the method was investigated with color photoelastic fringes of a circular disk under diametric compression. Results showed that the method was effective to determine the principal-stress directions with reasonable accuracy.
