Study Of Rail Corrugation On Tangential Tracks Based On Self-Excited Vibration Of A Wheelset-Track-Sleeper System

There is a large amount of rail corrugation in railway tracks all over the world. Researchers have studied this issue for more than one hundred years, and proposed some remedy measures. However, so far there is not yet a commonly accepted and effective rail corrugation remedy method. Rail corrugation not only affects the service life of vehicles and tracks but also leads to a severe derailment accident. Therefore, the study on rail corrugation is of great significance to the development of the railway industry.Based on the view point of the friction coupling at the wheel-rail interface as the mechanism for formation of rail corrugation, a finite element model for a wheelset-track system on a straight track is established. In the model, motion of the wheelset is coupled with that of the rail by friction. Stability of a wheelset-track system is studied using the finite element complex eigenvalue method, which is provided by ABAQUS. And some new understandings of rail corrugation caused by friction-induced vibration are obtained. In this thesis, the influences of the friction coefficient, load, spring stiffness and damping of rail support on self-excited vibration of the wheel/rail system are also studied. Based on the numerical simulation results, the following conclusions can be drawn:Rail corrugation on a straight track due to self-excited vibration of the wheelset-track system when the wheelset carrying a large traction force or braking force is studied using the finite element software ABAQUS. The calculation results show that some unstable frequencies fall in the range60-1200Hz, which correspond to frequencies of rail corrugation. So, this method can be used to predict rail corrugation.The stability analysis of the wheelset-track system shows that with increasing friction coefficient, the propensity of the unstable vibration of the wheelset-track-sleeper system will increase. Therefore, the propensity of the occurrence of rail corrugation will increase.The complex eigenvalue analyses of the wheelset-track system under the symmetrical loading and asymmetric loading on the both ends of the axles show that with increasing load, the propensity of the unstable vibration of the wheelset-rail-sleeper system will increase. Under the same conditions, the more the axle loading, the more the propensity of rail corrugation occurrence.The effect of vertical and lateral track support spring stiffness on the system stability is studied. It is found that there is an optimal value of vertical track support spring stiffness, which can result in a good stability propensity of the wheelset-track system. Similarly, there is also an optimal value of lateral track support spring stiffness for the wheelset-track system stability.The track support damping has a significant effect on the unstable vibration of wheelset-track system. An appropriate track support damping can effectively suppress the unstable vibration of wheelset-track system.