Photoelastic stress analysis using an object step-loading method

Sensitive, computer-aided retardation phase measurement methods suffer from the problem of discontinuity, which, in turn, hinders faultless phase unwrapping for stress determination in photoelasticity. An object step-loading method is introduced in this paper to overcome such a problem. One advantage of the technique is that the entire loading-to-stress history is computed. In this paper, the theoretical aspects related to implementation of the object step-loading method in computer-aided photoelasticity are outlined, and experimental verification is performed on a birefringent model subjected to compressive loading by comparing stress values with those computed using the theory of elasticity.