Development of a Procedure to Characterize Residual Stresses Induced by Drilling

Modeling residual stresses induced by drilling remains an issue. However, even if some models are under development, their validation is limited by the absence of a universal characterization method of residual stresses inside the hole. This paper aims at presenting a procedure to characterize the residual stress profile induced by drilling. The principle is based on the preparation of a reference sample that has been pre-heat treated in order to remove bulk residual stresses without modifying its microstructure. Then the sample is instrumented with strain gauges before being cut into two parts. This enables on the one hand to estimate the elastic recovery after cutting and on the other hand to provide an easy access to the surface investigated. Finally a standard X-Ray diffractometer and an electropolishing technique are combined to estimate residual stress profiles in two directions (tangential and ortho-radial directions).