A Method for Detecting Isoclinics by Modified Isochromatics

Abstract

In the present paper, the authors propose a new method for detecting isoclinics by using modified isochromatics. The ordinary method of detecting isoclinics by a crossed plane polariscope has some difficulties in determining the precise location of isoclinic line because the fringe width of isoclinics is rather broad and isochromatics prevent observation of isoclinics, especially in high-stress regions. When we use circularily polarized light as incident light on the photoelastic model and observe the fringe pattern through an analyzer, we will get a fringe pattern of the isoclinics modified by isochromatics. If the isoclinics intersect the isochromatics at a large angle, the isoclinics can be detected more accurately than by the ordinary method and can be observed clearly in high-stress regions because this method uses modified isochromatics.