Wear on the side rail can give rise to maintenance problems. The Railway Technical Research Institute (RTRI) has studied the mechanism of side wear progress by examining the influence of contact conditions between the vehicle and track on the side wear rail. The study was based on a survey of actual states and indoor tests using -scale model wheels to clarify measures to delay the progress of side wear and reduce the frequency of rail replacement.
      An indoor test was carried out based on an actual state survey of attack angles versus generated lateral pressure trend on an actual track with a curve radius (R) of 400 m and 900 m. The influence of the attack angle and lateral pressure on side wear was determined from the test results (Fig. 1). The graphs show a clear trend of side wear progress under certain conditions roughly matching the measurement results on the actual track, and that the side wear shape progresses in accordance with the passing tonnage of trains. Furthermore, generated stress and contact point shifting in some combinations of the worn rails and wheels were observed from the three-dimensional elastic/plastic finite element analysis conducted, based on data of the section profile obtained from site measurements (Fig. 2). A new rail profile was developed to distribute contact stress with the current wheels as evenly as possible, and its effect on side wear reduction was verified by an indoor test. Plans are underway to study new wheels and rail profiles for more effective wear reduction and new more accurate prediction/evaluation methods of side wear.