Application of Miniature Ring-Core and Interferometric Strain/Slope Rosette to Determine Residual Stress Distribution With Depth—Part II: Experiments

The theoretical development of the interferometric strain/slope rosette (ISSR) and ring-core cutting method is described in Part I of the paper [K. Li and W. Ren, ASME J. Appl. Mech.74(2), 298–306 (2007)]. In Part II, experiments are presented to demonstrate the applicability of the method. The procedures of experimentation are developed. An ISSR/ring-core cutting system was established and its measurement stability and accuracy were examined in a two-step measurement program. By repeating the two-step measurement procedures, several incremental ring-core cutting experiments were conducted. Residual stress distribution is calculated from the measured ISSR data by using the relaxation coefficients calibrated in Part I of the paper. Measurement resolution, accuracy, and sensitivity of the ISSR/ring-core method are evaluated. Tests on a titanium block show the reliability of the method in comparison with the results obtained by using other measurement methods. The new method is also applied on a laser weld which demonstrates its uniqueness to measure residual stresses in small areas with high stress gradients. The experiments show advantages of the ISSR/ring-core method, such as miniature size, noncontacting nature, and high sensitivity. The method can be effectively used to measure residual stress distributions with depth on various manufactured components.