Residual stress field in hole-drilling method-part I:Theoretical analysis

During the residual stress measurement by using the hole-drilling method, a work-hardening layer near the hole will be formed due to the cutting force.As the material characteristics in the work-hardening layer will vary evidently, the layer surrounding the hole can affect the stress relieved after hole drilling.The workhardening layer was simplified as a heterogeneous annulus by increasing the elastic modulus of the material near the hole, and the analytical solution of the release stresses after drilling in a infinite plate submitted to the biaxial uniform stresses was developed by using the method of elasticity.The release stresses in a 304 stainless steel plate under the biaxial stresses were numerically calculated by the FEM program MSC/Patran &Nastran and compared with the analytical solution.The results indicate that the simplified model is feasible and the analytical solution is valid.When the residual stresses are determined by using the hole-drilling method, it will be more accurate if the work-hardening layer is considered.