Residual Stress Using X-Ray Diffraction Techniques—Unified Approach

Abstract Many residual stress measurements techniques using X-ray diffraction have been developed to optimize fabrication processes and enhance the fatigue resistance of components in various sectors, including automotive, aerospace, structural, and medical industries. The accuracy of residual stress measurement results is critical to the success of these components. It has been scientifically established that stress measurement involves a series of steps: measuring d-spacings, determining strain in different directions, and then calculating stress using Hooke’s law, applied to either isotropic or anisotropic materials. While these steps may appear different across techniques, they ultimately share the same assumptions and fundamental theory, leading to the same result. In this paper, we demonstrated that all residual stress measurement techniques follow the same fundamental principles, with differences primarily arising from the geometry of the instrument used. Furthermore, any deviation from these steps will lead to erroneous results.