A Study On The Wheel/Rail Contact Problem Of Low-floor Trams

With the development of urbanization and the population increasing in city, the public transport not only requires large quantity but high quality. Light rail vehicles, of solving city traffic, are widely accepted by people, and are studied systematically. There must be many differences in the bogies between conventional vehicles and the low-floor Light Rail Vehicles. First, traditional wheel set, which includes an axle and two wheels, is not suitable for the low floor of Low-floor Light Rail Vehicles. As a method of reform, the independently rotating wheels are introduced, which abandon the axle or fixes the stepped axles in order keep the spare space between two wheels.Independently rotating wheel usually includes two kinds: with common axle and with non-common axle, they have been used in light rails. Without longitudinal creep, the critical velocity of hunting is higher to railway vehicle with independently rotating wheel, this may be potential application to high-speed locomotive and vehicle; In the meantime, By virtue of crank axle and even no axle, it can solve partial or complete low floor in right rails. Researchers on locomotive and vehicle have accomplished a lot of study in theory- and experiment at home and abroad in this area.The elastic frictional contact problem of the wheel-rail curve negotiation is solved by using the parametric variation principle, the corresponding finite element parametric quadratic programming method and multi-substructure technique. Modeling five wheel contact models of different contact sides of the 100% Low-floor Trams'tread profile respectively. Modeling three wheel contact models of different contact sides of the 70% Low-floor Trams'tread profile. Computing contact state is effected by different tread, axle loads, curve negotiation speeds, tractate forces and lateral forces, and then contact force and contact stress field are obtained, which is reflected by table and curve. The results show that 100% of low-floor trams'tread satisfy the requirements of the independent wheels more than 70% of low-floor trams'tread in most case. The variation laws obtained, which offers of the contact force and contact stress field with parameters above are theory basis for finding the method which can improve the design of low-floor light rail vehicles'tread.