Applicability of an Hertzian-type contact model for wheel-rail pairings as seen by an improved post-processing scheme for ultrasonic data

The contact between wheel and rail crucially affects the management of railways, since the vehicle dynamics, safety, and performance, for example, are all dependent on this. Therefore, in this contribution the loaddependence of nominal contact area - a broadly not considered aspect of the wheel-rail contacts within the literature - is addressed. We are applying an ultrasonic technique for the detection of the contact zone and an improved post-processing scheme for the measured ultrasonic reflection data. Accordingly, we found that the nominal contact area shows a power-law dependence on load which only on average is predicted by the elliptical Hertzian contact theory.