Hill Engineering recently published new research detailing our efforts to validate the PSR biaxial mapping technique for residual stress measurement.
This new technique generates two-dimensional maps of additional residual stress components over the same plane as the original contour method measurement. The paper is titled Assessment of Primary Slice Release Residual Stress Mapping in a Range of Specimen Types and appears in the November 2018 volume of Experimental Mechanics.
This paper further explores the primary slice removal technique for planar mapping of multiple components of residual stress, and describes application to specimens with a range of alloys, geometries, and stress distributions.
Primary slice release (PSR) mapping is a combination of contour and slitting measurements that relies on decomposing the stress in a specimen into the stress remaining in a thin slice and the stress released when the slice is removed from a larger body. An initial contour method measurement determines a map of the out-of-plane stress on a plane of interest. Subsequently, removal of thin slices and a series of slitting measurements determines a map of one or both in-plane stress components.
Four PSR biaxial mapping measurements were performed using an aluminum T-section, a stainless steel plate with a dissimilar metal slot-filled weld, a titanium plate with an electron beam slot-filled weld, and a nickel disk forging. Each PSR mapping measurement described herein has one (or more) complementary validation measurements to confirm the technique. Uncertainty estimates are included for both the PSR mapping measurements and the validation measurements.
Agreement was found between the PSR mapping measurements and validation measurements showing that PSR mapping is a viable technique for measuring residual stress fields.