Automatic determination of isostatics in two-dimensional photoelasticity

Abstract

We present a method for automatic determination of isostatics from the photoelastic measurement of isoclinics obtained by phase-shifting techniques. The method is based on the integration of two difference equations by use of a multigrid algorithm, using a quality map obtained from experimental data by checking the consistency of the generated experimental differences. So-called isostatic sulfaces are determined and, from them, the isostatics net can be drawn with any prescribed density and resolution. The algorithm is very robust and fast and has proven very efficient for working with real photoelastic fringe patterns.