Research On The Contact Between Wheelsets And High-speed Turnout

Turnout is an important component of railway track. Complex turnout structure causes the complex contact relationship between wheel and rail, the serious worn of wheel and rail, the short life of turnout and short replace cycle, and increases the operation cost of railway. As the train speeds increase, the contact between wheel and rail become more complex, which needs high require about the quality of the turnout. Solving the problem of the relationship between wheel and turnout has vital significance on the speed train operation safety, the reduction of the transportation cost and the development of high-speed train.The profile of the 60kg/m rail No.18 high speed turnout and the 50kg/m rail No.9 fixed frog of high manganese steel have been measured in this dissertation. Following phenomenon can be found in the survey:the light ribbon on the wing rail of high-speed turnout is not in the centre on the top and the flash issue occurs along the gap between the long point rail and the short point rail. To sum up the regulation of the wheel-rail contact state, the contact patch and the Mises stress in the rail during the wheels passing through the turnout, analyze the reason of the abnormal light ribbon on the wing rail and the flash issue on the point rail, and to compare high-speed frog with urban rail frog, based on the finite element method, a lot of three-dimensional models are set up according to the profile data of wheel and turnout which is from measurement in the survey, and do a lot of calculation, including five kinds of wheels contact with high-speed turnout and urban railway frog.The results show as follow:The shape, the size and the position of the wheel-rail contact patch and the Mises stress in the rail change continually during the wheel passing through the turnout. The lateral position of the contact patch is close to the inside of the rail during the wheel passing from stock rail to the switch rail, and the Mises stress in the rail is smaller at two point contact position. When the wheel passes through the connecting part, the wheel-rail contact patch is on the centre of the rail top at the position 20m away from the trip of the switch rail, and the flange root contact with the rail at the position 30m and 40m away from the trip of the switch rail. The contact patch closes to the inside continually when the wheel passes from the root of switch rail to the end of the connecting part. The contact patches between different wheels and wing rail shows that the contact patches area between worn JM3 wheel and wing rail at the position 10cm away from the trip of the point rail is the largest, followed by standard JM3 wheel, then is the worn XP55 wheels, finally is standard XP55 wheels. The contact patches of JM3 wheels and XP55 wheels are very different. It is worn JM3 wheel that cause light ribbon abnormal. Flash issue occurs along the gap between the long point rail and the short point rail at the position 2.2m to 3m away from the trip of the point rail. From geometric smooth, the frog with moveable-point rail has higher regularity than the fixed frog. The contact patch of high-speed turnout is wider, longer and larger than the urban railway frog.The study method and ideas in this dissertation provided the theoretical basis for the rational design of structure and the profiles optimization of the turnout, and it is applicable to the analysis of other types of turnouts.