Research On Magnetorheological Braking Technology Of Subway Vehicles

As the fast urbanization course of China, lots of problems of urban public transport come out. Subway can solve these problems effectively. There are some shortconmins fof subway transportation. Subway vehicles work environment is underground. Also, they need to start and brake frequently. Frequent braking will lead to a high risk of abrasion and brake-shoes deformation. Furthermore, acute friction will bring much dust to the air and pollute subway interspaces. As a new technology, non-friction braking is an effective way to make these problems solved.At present, non-power vehicles mainly use air braking. As to the subway, those power vehicles have used non-friction braking such as regenerative braking. If the non-power vehicle could also use non-friction braking, it can figure those serious problems out perfectly. So, this thesis focuses on another non-friction braking technology——Magnetorheological braking, applied on non-power vehicles.Firstly, several non-friction braking technical are introduced and advantages of Magnetorheological brake used in railway transportation are analyzed. Taking Chengdu metro line1as an example and considering its non-power bogie structural characteristics, the overall structure of Magnetorheological brake is designed and component correlative parameters are confirmed.Secondly, the braking torque of the brake is computed in Matlab/Simulink. Influence factors to the braking torque such as structure and material are analyzed. The feasibility of the device is verified theoretically. Control parameters are provided to the brake controlling system.Then, from the basic theory of electromagnetic field, the analysis method of magnetic field is chosen and confirmed. The principle of Magnetorheological brake is analyzed and validated by2-D Magnetic-Nodal method in ANSYS which is finite element analysis software.Lastly, based on the theory of thermodynamics and stress field, transient temperature and stress field of the brake equipment are analyzed during the whole process that Chengdu Metro Line1trains run once and return to the starting point. Equipment temperature and stress field as well as displacement deformation are analyzed in ANSYS. In addition, the temperature field in emergency braking situation is simulated. The conclusion shows that the Magnetorheological brake equipment designed in this paper meets the temperature stander and the stress field stander.