Plotting of isoclinic phasemap from finite element results and its use in digital photoelasticity

Digital photoelasticity is an experimental method for determining stresses in 2D and 3D models. In digital photoelasticity one gets a wrapped isoclinic phasemap. The main issue with wrapped isoclinic phasemaps is that the isoclinic values obtained do not uniformly represent the principal stress direction of one of the principal stresses consistently over the entire domain. These zones are labelled as inconsistent zones. Such zones need to be identified and corrected to get unwrapped values of continuous isoclinic phase values. In this paper, a method is developed to plot the simulated wrapped and unwrapped isoclinic phasemap from 2D Finite Element (FE) results so that one can use this as a convenient tool for identification and correction of inconsistent zones in isoclinic phasemaps obtained experimentally for complex problems. The method is explained by using the problem of a circular disc under diametral compression. The application of this method for handling complex problems is demonstrated by solving the cantilever bending of a binocular specimen.