Study On The Tire Wear Mechanism Of Urban Straddle Type Monorail Vehicles

In recent years, the urban railway transit has gradually become the mainstream traffic type in the urbanized advancement. Straddle type monorail transit is a new type which used the rubber pneumatic tires as the running pattern. This new type of urban railway transit traffic system can satisfy the development requirement of mountainous region city, small and medium-sized city and coastal city, so it has been widely applied in many countries. But, for these reasons such as: the special structure of its bogie, the surface quality and the alignment characteristics of its running track, incorrect driving manipulation of its driver which caused serious irregular tire wear and uneven wear problems of straddle type monorail vehicle.This dissertation studied on the mechanism of straddle type monorail vehicle tire wear and analyzed the impact of the dynamic changes of monorail vehicle motion state on tire wear which based on the science & technology project of Chongqing Municipal Education Commission(No.KJ120415) “Tire wear mechanism of urban straddle type monorail vehicle”. The main research contents are as follows:(1) This dissertation established rubber pneumatic tire mechanical properties model under the steady-state cornering condition and cornering-brake composite condition. And furthermore, this study utilized the virtual prototype software ADAMS to simulate the monorail vehicle driving condition at the same time introduced the lateral main factor and longitudinal main factor of tire wear which used to established the relationship curve of different vehicle motion state between slip rate, longitudinal wear main factor, side slip angle and lateral wear curve main factor.(2) In view of finite element method this dissertation described the whole finite element modeling scheme of monorail vehicle running wheel and used the ABAQUS’s subprogram VFRIC input this tire wear model into the finite element calculation program, thus, calculated and analyzed the tire tread wear contour in five kinds of typical motion state in the finite element software.(3) This dissertation combining the dynamic characteristics of the straddle type monorail, setting a“car body- tire- track beam” system dynamic model, and based on this model we using the multi-body dynamics software ADAMS to explore the relationship between tire wear and the dynamic changes of straddle monorail vehicle’s motion state.(4) This dissertation studied the affection of straddle monorail vehicle motion state’s dynamic changes on the tire wear through three different methods: tire mechanics, finite element analyst, multi body dynamics, all of the results show that: In the longitudinal direction, when the tire slip rate is under 5%, the tire longitudinal wear main factor is almost 0, the vertical load on the tire have smaller influences on longitudinal main factor of tire wear. Only when the vehicle under the limit driving state, the slip rate for wheel and track beam surface reached 100%, the amount of tire wear is increasing with geometric series. In the horizontal direction, when the side slip angle is less than 5o(or-5o), the lateral main factor of tire wear is almost 0. Only when the side slip angle greater than 5o or in case of rain and snow weather the adhesion rate of track beam surface decreased and the tire cornering force reached the adhesion limit of track beam surface, the running wheels begin to sideslip and tire wear is becoming serious.