Research On The Dynamic Performance Of Radial Bogie Based On The Axle Beam Type Of Urban Rail Vehicle

With the attention of Chinese high-speed rail industry rising increasely, the urban rail transit system is also developing quickly.With the advantages of energy efficiency,environmental protection and punctuality, urban rail transit has gotten cities' attention. Metro is the most well known means of city public transportation, and has made great effect in improving traffic conditions and air quality. However, due to the restriction of small-radius curve in running route, traditional bogie hasn't been able to meet the dynamic performance of metro vehicle in reducing noise and wheel-rail wear. Therefore, it is a significative solution to use radial bogie to improve the operating performance and environment of metro vehicleThe trailer car radial bogie of metro vehicle designed in this paper has no abrasion, swing bolster or swing platform. The guide arm of axle box connected with the radial mechanism was redesigned in order to realize the functions of wheel alignment and guidance simultaneously.While metro vehicle running through the curve sections, the redesigned guide arm can effectively transmit the relative rotation between car body and bogie to wheelsets, which has an important practical significance to reduce noise and abrasion of metro bogie.The vehicle dynamic models equipped with symmetrical bogie which guiding wheelset and following wheelset both using the radial mechanism and asymmetrical bogie which only guiding wheelset using the radial mechanism were built in SIMPACK to compare the dynamic performance of two models. The results show that the critical speed of vehicle with asymmetrical radial bogie is 207km/h, while the vehicle with symmetrical radial bogie is 209km/h. The riding indexes of two vehicles are both less than 2.5, meeting the standards of the dynamic performance. The curve passing safety indexes of two vehicles are less than the limit value set in GB/T5599-1985. Overall, the curve passing perfeomance of guiding wheelset with asymmetrical bogie is worse than that with symmetrical bogie while the trailer wheelset's curve passing perfeomance of asymmetrical bogie is better than that of symmetrical bogie,which indicates that the bogie with symmetrical radial mechanism can redistribute and reduce the wheel-rail lateral force effectively.In order to study the influence of flexible radial mechanism on bogie's guidance, the modal analysis and substructure analysis of radial mechanism were analysed in ANSYS. The rigid-flexible coupling dynamic model of vehicle with symmetrical radial bogie was built in SIMPACK, and the dynamic performances of rigid-flexible coupling dynamic model and rigid dynamic model were compared. The results show that the critical speed of the rigid-flexible coupling model is 198km/h, less than that of the rigid model. Both of the two models' riding indexes are less than 2.5, meeting the standards of the dynamic performance. Overall, the wheel-rail lateral force and lateral wheelset force of rigid-flexible coupling modle's guiding wheelset are greater than that of the rigid model's while the trailer wheelset has a opposite result. The derail coefficient and rate of wheel load reduction of rigid-flexible coupling model are less than that of rigid model while the wear index and angle of attack are greater than that of rigid model.The research results of this paper show that the curve passing performance of bogie with symmetrical radial mechanism is better than that with asymmetrical radial mechanism. The radial mechanism will weaken bogie's guiding function when it is considered as flexible mechanism. Therefore, it should ensure that the radial mechanism has enough stiffness when designed.