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 stresses, its practical application is standardised by the ASTM E837-08. For uniform residual stresses, to which the present work deals with, the use of the method in accordance with the ASTM limitations, leads to results with a bias of about 10%. Unfortunately, although some experimental parameters can be frequently out of the corresponding standard limitation, the user does not have appropriate procedures to correct the obtained results which, in accordance with the ASTM standard, have to be considered qualitative. In order to overcome such drawbacks as well as to permit 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 calculation code properly implemented in Matlab environment. The use of this tool permits to highlight the relative magnitude of the error and stress uncertainty of the main influence parameters.