High Accurate Residual Stress Evaluation by Deep Hole Drilling Technique Considering Three-dimensional Stress Fields >(

The deep hole drilling (DHD) technique has received much attention in recent years as a method for measuring through-thickness residual stresses. However, some accuracy problems occur with the DHD technique. One reason is that the traditional evaluation formula assumes that the stress condition around the reference hole is two-dimensional plane stress. In this study, a new evaluation formula and procedure are proposed using three-dimensional stress functions to evaluate the residual stress more accurately. Then, a known stress field is evaluated by the traditional formula and the new formula using the finite element method to compare the accuracy of the both results. These results indicate that the proposed formula can evaluate the residual stress better than the traditional formula can.