Research On The Relationship Between Wheelset Equivalent Conicity And Vehicle Dynamic Performance

High-speed rail as a quick and convenient means of transport, whether from the running speed, the degree of protection of the environment or from the terms of ride comfort has the incomparable advantage of other modes of transport. But with the improving of the velocity, the so called wheel/rail relationship also has been a higher requirement. Equivalent conicity as one of the important parameters in the wheel/rail relationship is of great significance to improve the vehicle dynamic properties. Vehicle dynamic properties include both the vehicle critical speed and the curving properties. Scholars at home and abroad have made a number of studies about it. But mostly is based on the existing tread or pure conical tread, failed to reveal the influence on vehicle dynamic properties by wheelset equivalent conicity. So work in this area need to be strengthened in the future.To investigate the impact of equivalent conicity on the vehicle dynamic properties, based on the geometric design method of wheel profile for improving wheel and rail contact status, a series of different conicity treads is designed, which matching with Chinese60kg/m rail. In order to analyze the quasi-static wheel-rail contact, dynamic performance and dynamic contact characteristics.The result of wheel/rail Quasi-static contact indicates that when the equivalent conicity increases slowly with lateral displacement, wheel/rail contact points distributed evenly. While the equivalent conicity of taper tread profile is essentially the same before flange reaching to rail. The contact spot area is small, the wheel/rail contact stress is higher than the worn tread, contact performance is bad.Vehicle dynamics analysis showed that, equivalent conicity of wheelset is the greater, vehicle lateral displacement is the smaller. The root of flange has a higher wheelset equivalent conicity could effectively inhibit the flange contact, reduce the number of rail and wheel flange contact, also help to improve the curving performance.Vehicle dynamics characteristics analysis showed that, with the improvement in the level of the wheel/rail surface conformal, although the wheel/rail contact spot area increases, the contact pressure density is reduced, but at the same time lead to the wheel/rail creep rate increases, so the wheel/rail frictional work power increases.The analysis of designed tread which considering the different rail cant shows that, in the same equivalent conicity case, rail cant can not impact the curving performance. But there is some impact on the critical speed, with the rail cant increase the vehicle critical speed decreased.