Recent advances in the hole drilling method for residual stress measurement

The main activities in the hole drilling residual stress measurement technique recently developed at the University of Pisa are reviewed and presented, Particular attention was paid to developing tools for increasing the limits indicated by the presently applied standard procedures for residual stress evaluation, For residual stresses that were assumed to be uniform through-thickness, the effect of plasticity was numerically analyzed and results formed the basis for a procedure that allows an increase in the maximum measurable residual stress up to 0.9 of the material yield strength, For nonuniform through-thickness residual stress, accurate analytical influence functions are proposed by which arbitrary interpolation of the influence coefficients is avoided and all the experimentally obtained strains, with no regard to their number, can be used as input for residual stress evaluation.