Inter-Method Comparisons of Residual Stress Measurement Data

Understanding the relationships between different residual stress (RS) measurement methods is critical for assessing the correlation between them. To evaluate the applicability of a given measurement method or technique for reliably determining RS for a specific component geometry, alloy, or material condition, inter-method comparisons are often useful. Different RS measurement methods have unique attributes regarding their ability to acquire and present a comprehensive picture of the RS state at any location within a part or component. In many cases, the residual stress information obtained using different methods is complementary rather than identical or nominally equivalent. Therefore, caution should be exercised when directly comparing RS data obtained using different methods, as different volumes of material are typically sampled by each. Given the overlap (or lack thereof in some cases) of the effective spatial ranges for various RS measurement methods, careful experimental design is required to ensure similar volumes of material are queried when directly compared. If done correctly, inter-method comparisons can provide a high level of confidence in the results obtained for specific applications of interest. Moreover, inter-method comparisons can expand the amount of information available by leveraging the inherent capabilities of each complementary method selected for use which can often be achieved by taking the most reliable portions of the data obtained using each method. The following paper will present the results obtained from a wide variety of RS measurement methods performed on wide a range of materials and discuss their significance.