Measurement of Residual Stresses on Deep Rolled Round Aluminum Samples Using Hole Drilling Strain Gage Method

Deep rolling is an established process to induce plastic deformation on the surface of engineering parts. As a result, a cold worked surface and a compressive layer of residual stresses are generated in subsurface regions. Thus, strength can be increased. Although deep rolling is mostly applied to axisymmetric parts with comparatively low diameters, effect of process parameters on induced stresses are usually investigated on flat surfaces. However, different residual stress profiles are expected in depth direction in flat and cylindrical parts. In the current study, residual stresses induced in deep rolled round EN AW-6082 aluminum samples with a diameter of 14 mm were measured using hole-drilling strain-gage method. Hole drilling calibration matrices were derived using finite element simulations. These matrices were compared with the ones used for flat specimens. Evaluated residual stress profiles by using these matrices were compared for both a flat workpiece and cylindrical workpiece.