Stress Calculation Error Analysis for Incremental Hole-Drilling Residual Stress Measurements

Abstract

The incremental hole-drilling method for measuring non-uniform residual stresses gives stress results that are very sensitive to errors in the measured data. The resulting stress errors can easily become large enough to compromise seriously the usefulness of the calculated stress results. This paper describes a straightforward method for calculating the stress range that has a specified probability of containing the actual residual stresses. Knowledge of this range allows informed interpretations of the stress results to be made. The four measurement error sources considered are: strain errors, hole depth errors, uniform hole diameter errors, and material constant errors. Both the Integral and Power Series stress calculation methods are investigated, and their different responses to measurement errors are described.