Contour Method: Principle

Measure multiple stress components using one cut, multiple techniques, and superposition

To measure multiple stress components with multiple cuts see:
Pagliaro, P., Prime, M. B., Swenson, H., and Zuccarello, B., "Measuring Multiple Residual-Stress Components Using the Contour Method and Multiple Cuts," Experimental Mechanics, 50(2), pp. 187-194, 2010. (LA-UR-09-01120)

Basic Contour Method:

The Contour Method is Based on an Elastic Superposition Principle:

Start with your part. These are the residual stresses that you would like to measure
Experimentally cut the part in two. The part will deform from the release of the stresses Then experimentally measure the contour, or shape, of the newly created surface

Now analytically force the cut surface back flat. This gives the original residual stresses normal to the cut plane! It really is simple, but gives you a full 2-D map of the original residual stresses over the cross-section of the part!

Details:

Cut the part in two using wire EDM
Measure the contour of the cut surface
Calculate the stresses by forcing the surface back flat in a finite element model

			Managed by Triad National Security, LLC Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA contact: Mike Prime at prime@lanl.gov \| Copyright & Disclaimer U.S. patent 6,470,756 \| Last Modified: July 28, 2017