A novel method of utilization of birefringent coating as an effective NDE tool

The photoelastic or birefringent coating technique is a unique tool for quick and reliable estimation of wholefield stress/strain distribution at any location in a loaded structural component. This technique can also be used as a powerful DT tool. This requires loading of the component to a sufficient level (straining to about 300 microstrain) to obtain enough response in the photoelastic coating. Use of "reverse loading concept/method" enables overcoming this problem to a great extent, This paves way for extensive application of this method with its advantages of high reliability and simplicity. Demonstrative examples for validating this concept along with the discussion of the related experimental/test parameters are presented.