ABSTRACT
The dynamic loads which arise from railway vehicles rolling over discrete irregularities such as wheel-flats and joints cause significant damage to vehicles and to the track itself. The terminology of “P1” and “P2” forces, representing respectively the high frequency and low frequency components of the response of track and vehicle to such defects, has entered the vocabulary of the railway engineer and simple formulae have been derived for the approximate amplitudes of the components of force. Parameters for the vehicle model are found by fitting its dynamic response to that found in an experiment in which the vehicle wheelset is isolated from the track by a resilient layer while maintaining the dead load on the suspension, and excited using an instrumented hammer.
