Toward more accurate resudual-stress measurement by the hole-drilling method: Analysis of relieved-strain coefficients

In residual-stress measurement by the holedrilling technique, accuracy can be enhanced if the proper values for the relleved-strain coefficients are employed. These values are obtained by double integration of the relieved strain over the area of the grid. In this paper, several methods customarily used in the literature for the calculation of these coefficients are discussed. A comparison of the coefficients from these methods and those derived by double integration demonstrate the increased accuracy of the latter.