Failure of a wheel/rail contact is usually by wear or fatigue and both of these depend on the size and location of the contact patch. One contact measuring approach that shows promise is by the use of ultrasonic reflection. If the wheel and rail surfaces make contact and are under high stress they are more likely to transmit an ultrasonic pulse. However, if there is no contact or the contact is under low stress then the wave is completely or partially reflected. By measuring the proportion of the wave reflected it is possible to deduce the extent of the contact area and also estimate the pressure distribution. In the described method a 2 dimensional scan is achieved by using an array transducer that performs a simultaneous line scan. This coupled with the speed of travel of the contact patch over the sensor location can achieve a map of the contact. Specimens were cut from wheel and rail sections and loaded together hydraulically in a biaxial frame. An array transducer was mounted beneath the rail specimen. The array transducer consisted of 64 ultrasonic elements and all transducers were pulsed simultaneously at repetition rates of 20 kHz. The signals were reflected back from the contact to effectively produce a line scan. The transducer was physically moved, to simulate the translation of the contact patch and so generate a series of reflection profiles. Contacts under a range of normal and lateral loads have been measured and compared with some simple results using pre-inked paper. The paper concludes with a discussion of how this array measurement procedure might be implemented at full line speed and what accuracy could potentially be achieved.


    Zugriff

    Zugriff über TIB

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    A rail mounted ultrasonic sensor for contact patch measurement


    Beteiligte:
    Dwyer-Joyce, R.S. (Autor:in) / Yao, C. (Autor:in) / Lewis, R. (Autor:in) / Zhang, J. (Autor:in) / Drinkwater, B.W. (Autor:in)


    Erscheinungsdatum :

    2008


    Format / Umfang :

    6 Seiten, 9 Bilder, 14 Quellen




    Medientyp :

    Aufsatz (Konferenz)


    Format :

    Print


    Sprache :

    Englisch




    JRC2008-63032 A Rail Mounted Ultrasonic Sensor for Contact Patch Measurement

    Dwyer-Joyce, R.S. / Yao, C. / Lewis, R. et al. | British Library Conference Proceedings | 2008


    Experimental characterization of wheel-rail contact patch evolution

    Marshall, M.B. / Lewis, R. / Dwyer-Joyce, R.S. et al. | Tema Archiv | 2006


    An ultrasonic sensor for monitoring wheel flange/rail gauge corner contact

    Dwyer-Joyce, Rob S / Yao, Chris / Lewis, Roger et al. | SAGE Publications | 2013


    An ultrasonic sensor for monitoring wheel flange/rail gauge corner contact

    Dwyer-Joyce, Rob S. / Yao, Chris / Lewis, Roger et al. | Tema Archiv | 2013


    Wheel-Rail Contact Patch Geometry Measurement and Shape Analysis Under Various Loading Conditions

    Radmehr, Ahmad / Ahangarnejad, Arash Hosseinian / Pan, Yu et al. | British Library Conference Proceedings | 2020