AN ACCOUNT OF PLASTICITY IN THE HOLE-DRILLING METHOD OF RESIDUAL-STRESS MEASUREMENT

The elastic-plastic stress-strain field produced in a thin plate under equibiaxial loading during the operation of drilling a through-thickn ess hole was analysed. The plane stress condition and Tresca yield cri terion were assumed for an elastic-perfectly plastic material. These h ypotheses allowed the problem to be formulated by means of ordinary di fferential equations which were analytically solved. Within these part icular conditions, the results gave indications of the effect produced by plasticity on the widely used hole-drilling method for residual st ress measurement. In particular, the equality of final results with th ose obtained for a plate with a pre-existing hole loaded in an elastic -plastic regime gives useful indications for the experimental analysis of the effect of plasticity on residual stress measurement.