Finite element validation of the deep hole drilling method for measuring residual stresses

The influence of free surfaces, local geometry and plasticity on the residual stress analysis by the deep-hole drilling (DHD) method is addressed in this paper. A finite element (FE) analysis using the commercial software ABAQUS was used to model a number of selected specimens that had been subjected to thermal process conditions that create initial residual stress fields. The essential steps of the DHD method were then simulated at a selected number of locations through the specimens. Two sets of analyses were conducted; one set assumed only that the process of simulating the DHD method was entirely elastic. The second set assumed that the DHD process was elastic plastic. In the majority of the test cases the conventional DHD method is shown to provide reconstructed in-plane residual stresses that agreed well with the initial residual stresses and did not suffer from expected near free-surface or geometric effects. The results for the out-of-plane residual stresses were however dependent on the assumed state of stress and the interpretation of the axial distortions. The reconstructed out-of-plane residual stresses were shown to have limited agreement with the initial stresses. For the elastic plastic study, results from a ring welded cylinder were successfully mapped on to a DHD model. A new incremental technique was shown to reconstruct the initial in-plane residual stresses with reasonable accuracy with only limited success for the out-of-plane stress. (C) 2012 Elsevier Ltd. All rights reserved.