The contour method is a residual stress measurement technique that provides a two-dimensional map of residual stress on a plane. Hill Engineering’s most recent case study explores how we determine the uncertainty in these measurements.
The model error is estimated by taking the standard deviation of the residual stress results using displacement surface profiles that have been fit with different analytical models (centered around what was determined to be the best fit). Each case uses a different number of fitting coefficients.
The total contour method uncertainty is then taken as the root-sum-square of the displacement and model errors with a minimum value of uncertainty set as a floor.
An illustrative example of the contour method uncertainty calculation is provided in the case study.
Read the full case study for a more in-depth description. If you have any further questions about contour method uncertainty or any of the residual stress measurement techniques we offer, please feel free to contact us.