Understanding the effect of residual stresses in critical for the structural integrity of railway and other mechanical components [1–3]. The most important methods for residual stress measurements are introduced, together with their main advantages and disadvantages [4]. Neutron and synchrotron strain measurements performed in European Synchrotron Radiation Facility (France) [5], Institut Laue Langevin (France) [1], Diamond Light Source (UK) [6,7] and ISIS Neutron and Muon Source (UK) are described. They allow the in-plane components of the stress tensor acting in cross-sectional rail slices to be mapped [8–10]. Alternative techniques such as laboratory X-rays and magnetic measurement systems MAPS are also depicted, showing coarser detail but similar trends than previous methods. Stress balancing appears to be worst in zones where significant plastic deformation takes place [11,12]. In addition, the measurements are complemented with contour method analysis to map the longitudinal stress components.
REFERENCES
[1] J.F. Kelleher, Residual Stress in Railway Rails, PhD thesis, University of Manchester, School of Materials, 2006.
[2] B. Moreno, A. Martin, P. Lopez-Crespo, J. Zapatero, J. Dominguez, Estimations of fatigue life and variability under random loading in aluminum Al-2024T351 using strip yield models from NASGRO, International Journal of Fatigue. 91 (2016) 414–422.
[3] C.A. Simpson, S. Kozuki, P. Lopez-Crespo, M. Mostafavi, T. Connolley, P.J. Withers, Quantifying fatigue overload retardation mechanisms by energy dispersive X-ray diffraction, Journal of the Mechanics and Physics of Solids. 124 (2019) 392–410.
[4] P.J. Withers, H.K.D.H. Bhadeshia, Residual stress. Part 1 - Measurement techniques, Materials Science and Technology. 17 (2001) 355–365.
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