An Asymmetrical Application of Contour Method in Measuring Residual Stresses

Residual stresses play a significant role in many material failure processes such as fatigue, fracture, stress corrosion, cracking, buckling and distortion. Experimental methods for determining the residual stresses are divided into destructive and non-destructive techniques. Contour method is a well-known destructive technique that provides a two dimensional map of residual stresses. In this method, a part is cut in two using a precise and low-stress cutting technique such as Electric Discharge Machining (EDM). The application of this technique mostly relies on a symmetric cut of an engineering component. In the current study, contour method was examined when the position of the cut is not symmetric. The residual stresses were measured along an asymmetrical line in quenched blocks. The process was also simulated using finite element analyses. The measurement along the asymmetrical line required a calibration technique to achieve the correct distributions of residual stresses. The measured stresses were compared with those obtained numerically.