Design Of MR Damper Applied In Train And Vertical Vibration Reducing

With the continuous improvement of the train running speed and increasement of train body vertical vibration, passive shock absorbers unable to meet the demand of vibration reduction, semi-active vibration absorbers become the trend of train absorber. The content of this paper includes designing magnetorheological damper(MRD) that used on a laboratory train model, analysing the influence of train damping coefficient to the train body vibration and carrying out the train body vibration reduction experiment. It's a subject with high practical value.Damping ratio method was put forward to calculate the damping force of MRD and its reliability was verified by the parameters of real train. The maximum damping force of MRD that used on laboratory train model was estimated by damping ratio method.By comparing theory and experiment maximum damping force of four different dampers, the design model was found to be unable to accurately estimate all range MRD maximum damping force. To solve this problem, adjustment coefficient was added to the design model. Maximum damping force of different structure parameters was analysed and the structure of the MRD is optimized.MRD's magnetic field was simulated in ANSYS and magnetic field intensity of different structure diameters was analysed. The maximum sum of magnetic field intensity was used as the goal to optimize structural parameters. Numerical results indicate that optimized magnetic field intensity of the working gap is increased by 21%.In order to analyse the influence of damping coefficient to the train body vibration, two-degree-of-freedom vehicle model was established in Simulink and its reliability was verified by using vibration transmissibility. Through loading track random excitation to train body model, the maximum car body acceleration mean square value and its change tendency under different running speed and different damping coefficient were obtained.The train body vibration reductuion experiment was carried out. Experiment showes that installing MRD significantly reduces the mean square value of train body vibration acceleration.