Probabilistic Evaluation of Residual Stresses for Hole-Drilling Tests

The article focuses on the application of a probabilistic approach to the evaluation of residual stresses in tensometric (strain gauge) hole-drilling methods. The principle of this method is based on the use of a strain gauge rosette on the surface of the tested component and the subsequent drilling of a hole in the centre of this rosette. This disturbs the internal force and moment equilibrium, which in turn causes surface deformations that are measured by the rosette. The measured deformations are then evaluated, and derived theories are applied to determine the course and magnitude of residual stresses taking into account the random character of the input parameters using the SBRA (Simulation-Based Reliability Assessment) method, which proves to be highly practical. The probabilistic approach to determining residual stresses is a new, original approach which brings a suitable and accurate description of the variance in measured values.