Study On Dynamic Performance Of Three-module Low Floor Tram

At present,the urban scale of our country is gradually expanded,and the process of urbanization is accelerated,the original transportation cannot fully meet the needs of the public and the city's traffic is seriously congested.Modern tram as a safe and reliable,comfortable and beautiful,green environmental protection rail transit tool is favored by many domestic cities,which is in line with the future development plan of the city and gradually becomes the research focus of domestic rail vehicle suppliers.In recent years,the tram was developed rapidly in China and many cities have intentions to build the tram,but the research on the modern tram is started late in China.Domestic rail vehicle suppliers began to study the tram in recent years,mainly through technical cooperation or technology introduction to make trams,and need to learn from the successful experience of foreign countries to develop the localized low floor tram.The development course and application status of the tram at home and abroad were summarized in this paper,the structure of the tram,the types of bogies and the technical characteristics were introduced,and the significance of exploring tram was expounded.Based on the three module low floor tram,the paper introduces the structure of the vehicle,the bogie type,and the structural characteristics of the workshop connection device.According to the vehicle structure and related technical parameters,the tram simulation model including the biaxial bogie and the single axle bogie was established,some components were simplified in the modeling process,and the principle of vehicle dynamics calculation was discussed.In order to make the tram have good running characteristics,according to the national standard GB/T 5599-1985 "Railway vehicles-Specification for evaluation the dynamic performance and accreditation test",the suspension parameters of the simulation model are optimized and analyzed.During the optimization process,the parameter optimization of the biaxial bogie and the single axle bogie was considered separately when the suspension parameters of the simulation model were optimized,the influence of suspension parameters on the running performance was studied when the vehicle run on a straight line and passed a certain radius curve,and a set of good suspension parameters was selected.Let the vehicle run on straight line and different radius curves,and the optimized parameters were used to predict and analyze its performance.The simulation results showed that the nonlinear critical speed of the tram was 141km/h,which meet the design requirements of the vehicle construction speed of 80km/h.The vehicle stability index was less than 2.5 inthe speed range of 70km/h,meeting the standard excellent grade requirement,when the vehicle was running on a straight line and a curve with a radius above 60 m,the wheel-axle lateral force,the wheel-rail lateral force,and the derailment coefficient were all within the standard range.The influence of the hinge parameters of the vehicle connection device on the vehicle performance was studied,the effect of the anti-yaw damper failure and the wheel-rail adhesion coefficient on the running performance of the tram were analyzed.The simulation results showed that the translational stiffness and flexural rigidity of the hinged device affected the vehicle running performance.The critical speed of the vehicle after the anti-yaw damper failure was only 61km/h,so it was needed to add an anti-yaw damper to improve the stability of the vehicle.The greater the adhesion coefficient,the lower the critical speed of the vehicle,the worse the stability,the more serious the vehicle wear;the adhesion coefficient was too smaller,the wheel-rail longitudinal creep force decreased,the wheel steering ability decreased,therefore,the sand,lubrication,polished rail and other ways were used to change the wheel-rail adhesion coefficient in the operation process,and improved the vehicle running conditions.