Research On Wheel-Rail Profile Matching Relation Of Metro Vehicles

Metro is an efficient, convenient, and fast means of transport. Operating speed of metro vehicle is significantly low than the railway vehicles, metro lines usually undergrounded, or elevated, the radius of curves is very small, vehicle operation lines relatively fixed. These features will inevitably lead to metro vehicle wheel/rail relationship having certain degree of particularity. As the mileage of metro vehicle operation increases, wheel tread wear becomes a serious problem, particularly abnormal wear, flange contact and tread shelling. Urban rail traffic abroad is more developed, so more research is done in this area, but in China there are relatively few studies, work in this area need to be strengthened in the future.To investigate characteristics of metro vehicle normally used wheel profiles, LM wheel profile, wheelset back-to-back distance1358mm and1360mm of S1002wheel profiles matching with60kg/m rail is considered. Wheel/rail steady state contact, vehicle dynamics and wheel/rail dynamic state contact simulation is carried out.Wheel/rail steady state contact indicates, wheel/rail contact points evenly distributes on LM wheel and rail profile, wheelset equivalent conicity increases with wheelset lateral displacement, wheel/rail contact patch is small, maximum equivalent contact stress is the highest, but the contact patch frictional work is the lowest. Whereas the2matching of S1002profile, wheel/rail contact points jumps on the wheel/rail profiles, wheelset equivalent conicity not increases with wheelset lateral displacement, wheel/rail contact patch is big, maximum equivalent contact stress is low, but the contact patch frictional work is high.Vehicle track coupled dynamics analysis shows, the3matching possesses nearly the same vehicle critical velocity, the LM profile exhibits a little bit better curving performance than the others.Wheel/rail dynamic state contact under rail irregular excitation indicates, on straight line, wheel/rail contact points evenly distributes on LM wheel/rail profile, the maximum pressure is comparatively high, the contact patch frictional power is the lowest. Whereas the2matching of S1002profile, wheel/rail contact points jumps, wheel/rail non-smooth contact cause relatively serious. During curving, on small radius curve with low speed, frictional power is the highest on LM profile, and maximum contact press on wheel flange of the2matching of S1002profile is very high. On bigger radius curve with higher speed, LM profile exhibits better curving ability, lower pressure density, smoother frictional power curve; and S1002profile wheel/rail contact is not smooth, press change greatly.These indicate that the LM profile having preferable contact status.