On image analysis for Birefringence measurements in photoelasticity

Abstract

A number of techniques have been proposed during the past twenty years that have the common purpose of automating photoelastic fringe analysis. These techniques, which are reviewed, include spectral contents analysis, phase-shifting or stepping and Fourier transform procedures. It is shown that all of the techniques are based on a common theory and, consequently, all of the analytical methods suffer similar disadvantages. There is some illustrated discussion of the sources of errors when making full-field measurements.