Comparisons of stress, heat and wear generated by AC versus DC locomotives under diverse operational conditions
A method is presented to estimate rail-road wheel/rail contact stresses, heat and wear generated by AC and DC drives on worn low and high rails. An investigation was carried out on the leading and trailing axles of the third locomotive, where the axle load is more severe than that on the first and second locomotives. Two types of locomotives (AC and DC) currently run in Australia were evaluated under diverse practical situations of in-service wheel-rail contact (wheel loads, angle of attack and adhesion level). A commercial finite element method software LS-DYNA was utilised to build a comprehensive wheel/rail contact model that was followed by an analysis for temperature and wear. This numerical model was constructed based on Australian standard wheel/rail profiles (ANZR1 wheel and 60. kg rail) and sub-components of the track such as railpads, sleepers and ballast. Moreover an analytical method and a shakedown diagram approach were also applied to evaluate the temperature rise on the rail and the response of the material, respectively. Calculation of the wear volume of the rail was based on Archard[U+05F3]s wear model. The results showed that the stress, heat and wear produced by AC locomotive were more severe than that by DC locomotive. Furthermore high contact stresses were found at the contact of low rail with the trailing axle (3rd axle).