ESTIMATION OF RESIDUAL-STRESSES IN RAILWAY WHEELS BY MEANS OF STRESS-INDUCED MAGNETIC-ANISOTROPY

A nondestructive inspection technique, based on stress-induced magneti c anisotropy, provides a means of quantifying the residual stress dist ribution in railway wheels. An automatic prototype device has been con structed; calibration measurements were carried out to examine the sen sitivity of the technique to metallurgical effects in the wheel grades of interest. The device was used to obtain residual stress informatio n on new and thermally damaged wheels representing a range of service conditions. The validity of the technique is examined using additional strain gauge measurements. A relationship is established between the output of the device and net circumferential stress within the wheel r im.