Measurement and prediction of the residual stress field generated by side-punching

Side-punching is proposed as a method of introducing a well-defined residual stress field into a laboratory-sized test specimen. Such a specimen may subsequently be used to assess the influence of residual stresses on the fracture behavior of materials. Side-punching consists of simultaneously indenting opposite faces of a plate of material with rigid tools, using sufficient force to cause localized yielding over a finite-sized volume of material adjacent to the punching tools. This paper presents experimental measurements, obtained using three independent measurement techniques, of the residual stress field generated in an aluminium alloy plate after side-punching. Incremental center hole drilling is used to determine the near-surface residual stress field, while synchrotron x-ray diffraction and deep hole drilling are used to measure the through-thickness residual stress field along a path linking the two punch center points. Finite element (FE) predictions are also presented and compared to the measurements. There is very good agreement between all three sets of measurements and the FE results, which all show that the through-thickness residual stresses are compressive and attain a maximum value at the center of the plate. The results confirm the potential use of side-punching in residual stress-crack interaction studies.