The Single Slice Method for Measurement of Axisymmetric Residual Stresses in Solid Rods or Hollow Cylinders in the Region of Plane Strain

Abstract

A new method is presented for the measurement of axisymmetric residual stresses in a solid rod or hollow cylinder in the region which is in a state of plane strain. The experimental procedure involves, first, making a complete transverse cut, normal to the axis of the part in the region which is initially in plane strain. Next, a number of strain gages are mounted on one of the faces produced by the first cut. A second transverse cut, parallel to the first, is then made to remove a thin slice containing the strain gages. It is shown that the change in strain gage readings due to removal of the slice may be used to deduce the axial stress in plane strain at the location of the first cut. The hoop stresses in the thin slice, which is in a state of plane stress, are readily obtained from the “crack compliance” procedure which we have described in earlier work. From this information and the initial axial stress in plane strain it is shown that the initial hoop and radial stresses in plane strain may be determined. The method is validated by obtaining the stresses in a water quenched rod which are shown to be in excellent agreement with those measured using a different experimental approach. Since the method does not require the measurement to be carried out on the original rod or cylinder, it allows the original residual stresses to be measured from a fractured shaft by making a slice near the plane of the fracture if the fracture is dominated by elastic deformation.