EVALUATION OF FINITE ELEMENT BASED CORRECTION OF LAYER REMOVAL DURING XRD MEASUREMENTS FOR GEOMETRIES AND STRESS DISTRIBUTIONS OF INTEREST IN AIRCRAFT ENGINES

摘要

X-Ray diffraction has evolved as one of the most practical methods to measure surface residual stresses. The method is regularly used to measure sub-surface stresses by removing thin surface layers by electro-polishing. When such layer removal is performed, the measured stress needs to be corrected for the stress relaxation and redistribution that occurs because of layer removal. The underlying principles of mechanics for this method are described by Francois et.al. [1]. Most standards on XRD measurements (e.g. SAE HS-784 [f]) cite analytical solutions derived and published in 1958 by Moore and Evans [3] as a recommended correction for simple geometries. We have extended these corrections by developing and implementing analytical solution for internal holes – a geometry of interest in aircraft engine applications.