MAGNETOACOUSTIC TESTING OF RAILROAD WHEELS: ASSESSING THE LABORATORY TO COMPONENT TEST TRANSITION

The magnetoacoustic test method has been shown through numerous laboratory investigations to have good potential for monitoring residual stresses in industrial components. This paper specifically addresses the difficulties that have hindered the evolution of this technique into a field tool capable of measuring residual stresses in the rims of railroad wheels. These hindrances include a need to decipher complex stress distributions in wheels of undetermined pedigree and interpreting the effects of inhomogeneous magnetic field distributions in the sample wheels Progress has been demonstrated through the finite element modeling of these concerns: thermal effects due to braking variables to predict stress patterns, and the magnetic flux distribution in a wheel rim during testing, have both been analyzed Further advances will hinge on corroboration with destructive tests, and the refinement of surface stress measurement capabilities via the magnctoacoustic method