XRD analysis of out-of-plane shear stresses by 2D-detectors

2D-detectors (image plate detectors) for the X-ray diffraction analysis of residual stresses offer a short radiation and measurement time, and better accessibility compared to measurements via 0D- and 1D-detectors. Residual stress evaluations with 2D-detectors based on the single exposure cosα-method measurements lead to deviations of the evaluated principal stresses, if out-of-plane shear stresses are present. Multi exposure measurements from 0°, 90°, 180°, and 270° direction may be able to determine out-of-plane shear stresses as well but require a longer measurement time and good accessibility to the measurement location. For these reasons, different techniques to determine out-of-plane shear stresses in residual stress fields with 1D- and 2D-detectors are compared based on sin²ψ- and cosα-method. To this end, out-of-plane shear stresses were induced by diamond burnishing in construction steel plates. High deviations in principle stresses were determined by single exposure measurements. Different measurement approaches based on multi-exposure cosα measurements were deployed to evaluate their accuracy in measurements of out-of-plane shear stresses.