The determination of principal stresses from photoelastic data

Current developments in the automation of photoelastic analysis have enabled the fast and accurate collection of the isochromatic and isoclinic parametersl from photoelastic specimens. Since the isochromatic parameter yields the difference in the principal stresses then a suitable procedure has to be used for their separation. This paper provides a survey of the stress separation techniques available with a view to incorporating the most suitable method into an automated full field polariscope.