Obtaining stress maps from photoelastic data using a digital computer

A general procedure for the analysis of photoelastic isochromatic and isoclinic photographs by digital computer to produce plots of coordinate normal and shear stresses is presented. The solution for normal stresses, involving a finite-difference iterative harmonization of the Laplace equation, is discussed, including treatment of the boundaries and selection of an appropriate network grid. The results of a classical problem, solved by this technique, are included.