Study On The Polygon Cause Of Coupling Vibration Of Resilient Wheel And Track

Rail transit is widely used in China’s transportation industry because of its rapid,efficient,and strong transport capacity,which greatly improves the convenience of people’s travel.With the increase of carrying capacity and the improvement of operation requirements,the wheel/rail operating conditions of rail transit are becoming more and more complex,and the wear problem of wheel/rail is becoming more and more serious.Wear has caused some problems,such as wheel rim fracture,track fracture,fastener shedding,and wheel non-circular wear.The safety service life of components is greatly shortened,and the comfort and safety of people’s travel are reduced.The wheel-rail system is the basis of many rail transit problems.The study of wheel-rail contact characteristics and wear law plays a very important role in solving many problems in rail transit.In this paper,the wheel-rail dynamic model,the theoretical model of resilient wheel vehicle,and the long-term wear model are built to study the contact characteristics of the resilient wheel,explore the causes of polygon wear of resilient wheel,and propose measures to suppress polygon wear.The main work is as follows :Firstly,according to the track train’s actual operating conditions and load conditions,based on the wheel-rail dynamic model and wheel-rail contact theory,the contact characteristics of the’ V ’ resilient wheel and rigid wheel are studied and compared.By simulating the wheel-rail’s static pressure and rolling process,the contact characteristics of the resilient wheel are proved.Using wheel-rail contact theory,the theoretical value of the maximum contact pressure is calculated,and the model’s validity is verified by comparing it with the actual value.Through the study of static pressure and the rolling process,the changes of contact stress,contact pressure,and contact spot of the resilient wheel are given,and the role of the resilient layer in the resilient wheel is analyzed.The results show that the contact spot area of the resilient wheel is larger than that of the rigid wheel,the contact spot shape of the resilient wheel is mostly stripped,and the contact spot shape of the rigid wheel is more point and block.At the wheel-rail contact position,the maximum stress of the resilient wheel is smaller than that of the rigid wheel,and the rubber block of the resilient wheel plays a certain buffering and energy absorption effect on the contact stress of the wheel-rail contact surface.Secondly,the vehicle dynamics and long-term wear models are established,selecting the appropriate wheel-rail contact parameters.Considering the modal vibration characteristics of wheel and rail,the resilient wheel and flexible rail are introduced to evolve the polygonal wear formation process of the train under the linear track.The high-order polygonal wear is evolved by taking the actual train parameters and the initial polygonal data of the wheel as input conditions.The wear results are in line with the actual situation,which verifies the correctness of the model and reveals the formation characteristics of the surface wear of the resilient wheel.Finally,based on the evolution of polygonal wear,the wear characteristics of resilient wheel locomotive under four speeds are studied,and it is found that the resilient wheel locomotive conforms to the ’ frequency fixed ’ mechanism.Considering the modal characteristics of wheelrail,the formation characteristics of polygonal wear under four working conditions of flexible wheel-rail,rigid wheel-rail,flexible wheel-rigid rail,and rigid wheel-flexible rail are analyzed.The effects of vertical damping and vertical stiffness of rail fasteners on the polygonal wear of resilient wheels were studied.The results show that the dominant order of polygonal wear of resilient wheel decreases with the increase of driving speed.The modal characteristics of rails promote the development and evolution of high-order polygonization of train wheels,while the modal characteristics of resilient wheels have little effect on the development and evolution of high-order polygonization wear.Increasing the vertical stiffness of rail fasteners can promote the polygonal wear of resilient wheels from high order wear to low order wear.Increasing the vertical damping of rail fasteners can inhibit the development speed of polygonal wear of resilient wheel locomotives during driving.