论文翻译轨道方面.docVIP

Slip -Stick Vibrations of Wheelsets and Rail Corrugations Liu Xueyi Introduction Slipstick vibrations are one of the forms of self excited vibrations. When a vehicle runs on a sharply curved track, the wheels are likely to slip during rolling on the rail since the difference of rolling radius between the outside and inside wheel is not enough for the wheelset to negotiate the curve. As the axles of a wheelset are elastic bodies, under some conditions, for example, the creep curve with a falling characteristic in the saturated part, slip -stick vibrations may be caused by the torsion or bending vibration of wheelset or the combined effect of them[ 1, 2]. T he slip -stick vibration is generally thought to induce rail corrugations on curved tracks[ 3]. But much of the formation mechanism of rail corrugations has not been successfully explained, for the research about the slip -stick vibrations is rather insufficient. There are two main shortcomings in the existing analyses. First, the simulating models are oversimplified in which only the torsion or bending vibration of wheelset is considered, but other vibrations in the wheel/ rail system are all omitted. Second, it has not been investigated how the slip -stick vibrations behave when the masses, stiffness and damping in the system vary over wide ranges. In fact, the slip -stick vibrations may show great differences. The rail corrugations are also likely to have various features. Obviously, it is necessary to further investigate the slip -stick vibrations and rail corrugations. 1 Dynamic Model The dynamic model developed in this paper based on Ref. [ 4] is a vertical lateral,space coupling, nonlinear and time dependent model for simulating the wheel/ rail system vibrations as well as the torsion and bending vibrations of wheelsets. 1. 1 Tracks in the model The longitudinal vibration of tracks can be neglected as compared with the vertical and lateral vibrations according to a field test ( to be published) . The ball