STUDY ON THE MECHANISM OF DISCONTINUOUS SUPPORT STIFFNESS ON THE DEVELOPMENT OF RAIL CORRUGATION

To minimum the adverse influence of rail corrugation on train operations and track maintenance, and to take effective measures for prevention and control, it is important to understand the cause of generation and development of rail corrugation, and analyze the influence factors on the corrugation. In the process of analysis, observation and tracking on the system for rail corrugation should be carried out to grasp the characteristics of rail corrugation. This paper describes the study of the fastener assemblies with different values of rail supporting stiffness using on-site tests with an impact excitation. The rail dynamic frequency response functions in both vertical and lateral directions were measured at positions which were directly over the fastener and also in the middle span of two fasteners along the rail. Through a large number of experimental data and analysis, it was found that the transfer functions clearly show opposite trends when the wheels running over on the fastener and on the middle span between two fasteners. This demonstrated that the discontinuous support is a main cause of rail corrugation. According to the experimental results, the support space and the rail stiffness should determine the characteristic frequencies of existing rail corrugation. The difference of rail response at the characteristic frequency is affected by the rail support stiffness, which can effectively inhibit the formation and development of rail corrugation.