Residual Stresses Measurement in UIC 60 Rail by Ring-Core Method and Sectioning Technique

The measurement of residual stress in rail foot, according to manufacturing standards is mandatory. In this study, the ring-core method and the sectioning technique are used to measure the residual stresses. A calibration technique for the ring-core method has been explained and simulated by the finite element analysis. The calibration coefficient has been determined for certain parameters and various depths of the annular groove. The ring-core method has been simulated for the uniaxial residual stress field and it is observed that the maximum error in the maximum principal residual stress was about 13% which is about 5% of material yield stress. The residual stresses have been measured at the UIC 60 rail foot by the ring-core method and the sectioning technique, and the results are in a good agreement with earlier investigations in this field. Also, it has been indicated that maximum residual stresses on the rail foot are not in the longitudinal direction and in the subsurface of the rail foot, the maximum principal direction coincides with the longitudinal direction. Both methods indicated tensile residual stresses on the rail foot, but the ring-core method predicted 27% higher longitudinal residual stress on the rail foot in comparing with the sectioning technique.