Error and Uncertainty Analysis of the Residual Stresses Computed by Using the Hole Drilling Method

The hole-drilling method is one of the most used techniques for the experimental analysis of the residual stresses in mechanical components. For both through-thickness uniform and non-uniform residual stress distributions, its application is standardised by the ASTM E837-08. In accordance with the ASTM limitations, the analysis of uniform residual stresses, to which the present work deals with, leads in general to results with a maximum bias of about 10%. Unfortunately, in general the user does not have appropriate procedures to estimate the actual stress error; consequently, if one or more of the experimental influence parameters fall out of the corresponding standard limitations, the computed residual stresses have to be considered as qualitative results. In order to overcome such drawbacks as well as to permit in general the estimation of the stress uncertainty, in the present work the procedures for the correction of the effects of the main error sources and for the stress uncertainty estimation, are proposed. The practical application of such procedures is carried out by using a simple calculation code properly implemented in Matlab environment. Also, the use of this tool allows the user to highlight the relative error and the stress uncertainty contribution of each influence parameter.