Towards effective phase unwrapping in digital photoelasticity

Phase-shifting techniques in photoelasticity have a peculiar problem of isoclinic–isochromatic interaction, which lead to ambiguous zones in phase map. A comprehensive discussion on the reason for the formation of ambiguous zones is presented in this paper. A new method is developed to remove this ambiguity in the phase map. The new methodology is validated with theoretically and experimentally generated phase maps. A flexible algorithm for phase unwrapping is developed using tiling. The applicability of this is demonstrated using various benchmark problems consisting of simply and multiply connected bodies and slices cut from stress frozen models.