The Influence Of Dynamic Performance Of EMU’S Wheelset Assembly

With the railway vehicles technology developing toward the orientation of high-speed and heavy-haul, vehicle dynamic performance is more and more sensitive to the parameters of the wheelset which is the major part of bogie. Research on the influence of the wheelset assembly parameters to dynamic performance will lay a solid foundation for the further development of vehicle technology. In this paper, the computing simulation method is adopted to study the parameters of wheelset assembly from aspects of wheelset tread, wheelset mass, natural frequency of the wheelset and so on.Wheel-rail contact geometry is influenced by the profile of wheelset tread. The wheel-rail contact geometry of LMA, S1002G and XP55are calculated and compared from the aspects of radius difference between rolling tread circles, equivalent conicity and contact points distribution. And wheel-rail contact characteristics of each kind of tread are summarized.The calculation result of vehicle dynamic performance after tread worn indicates that the main reason leading to the deterioration of vehicle dynamic performance is concave deformation caused by tread worn. Meanwhile, the wheel radius difference caused by asymmetric worn of the left wheel and right wheel also have influence on vehicle dynamic performance to a certain extent, but not so obviously.The wheel-rail impact dynamic action model when vehicle passing through low connector track is also established in this article, in order to research the influence of wheelset mass to wheel-rail vertical force. When the mass raises, the stability of vehicle significantly decreases and wheel-rail vertical force increases. The calculation result also shows that the increase of wheelset mass can enhance the wheel-rail vertical force P2, and enhance the destruction that the wheel-rail lash brings to track infrastructure.And rigid-flexible coupling model of vehicle system considering wheelset flexible is also established in this article, the critical speed of the vehicle is declined and lateral wheelset force as well as derailment coefficient is raised by taking the natural frequency of the wheelset into account in dynamic calculation. The changes are mainly caused by the7th natural frequency to the11th natural frequency, and higher natural frequencies affect vehicle dynamic performance insignificantly.