Research On Influence Of Wheel Tread Wear On Vehicle Dynamics

As the train travelling speed rising up in our country, the force between wheel and rail is growing up. The wear of rail and wheel is becoming more serious, this makes the vehicle dynamic performance worse, it will affect the vehicle stability, safety and comfort. The research on wheel tread wear and it’s influence on vehicle dynamics and the research on wheel tread repair is meaningful for reducing rail/wheel damage, improving vehicle dynamic performance and improving the economic and social benefits of railway transportation.With the data of worn wheel, combine with vehicle dynamic model, calculate the vehicle critical speed on straight line and vehicle dynamic parameter on curve line. In order to analysis the influence of wheel wear, design the worn wheel tread whit the data of one wheelset in different operating mileage. Wheel/rail steady state contact is carried out for worn wheel in wear condition. The analysis on vehicle dynamics is mainly on critical speed and curving performance. The dynamic contact analysis mainly focus on wheelset lateral vibration acceleration, wheelset dynamic lateral displacement and contact friction power to analysis the influence of wheel wear on vehicle. Curving performance mainly focus on wheelset lateral displacement, wheelset lateral force and wheel/rail friction power while passing through the ideal curve line with out excitation.The comparison of wheel rail contact geometry makes it clear that when the wheelset has a little lateral displacement the rolling radium difference gets bigger for worn wheel, the rail rolling radium difference doesn’t get bigger to control the increase of lateral displacement when the wheel set has a big lateral displacement. The conicity changes very much after wheel wear and even gets lower than zero, which is not good for vehicle performing. The distribution of wheel rail contact point doesn’t evenly after wheel wear, it jumps several times, and has a bad influence on wheel rail contact.The comparison of several dynamic character declines that the critical speed gets lower after wheel wear, with the growing of wear the critical speed gets lower first and get a little higher after a certain level of wear. The wheelset lateral vibration acceleration and wheelset lateral displacement doesn’t change very much after wheel wear but the wheel rail contact friction power gets higher. The wheelset lateral displacement, wheel rail lateral force and contact friction power get higher after wheel tread-wear in curve line. Compared with out-phase wheel tread wear, the in-phase tread wear exerts more obvious influence on vehicle dynamics.