Photoelasticity is an experimental method to determine the stress distribution in a material. The method is mostly used in cases where mathematical methods become quite cumbersome. Unlike the analytical methods of stress determination, photoelasticity gives a fairly accurate picture of stress distribution, even around abrupt discontinuities in a material. The method is an important tool for determining critical stress points in a material, and is used for determining stress concentration in irregular geometries.
Read more about Photoelasticity: History, Principles, Isoclinics and Isochromatics, Two-dimensional Photoelasticity, Plane Polariscope, Circular Polariscope, Applications