Comparative analysis of suspension frame structure of HTS maglev vehicle based on vehicle bridge coupling models

Because of the self-levitation, self-guidance, and self-stability characteristics, high temperature superconducting (HTS) trains are regarded as one of the ideal operation modes in ultra-high speed transportation. The suspension frame’s structure is critical because it is one of the most important components of the hightemperature superconducting maglev train. The vehicle bridge coupling models of different suspension frame structures were established. They need to be compared in terms of running stability, comfort, vibration transmission rate, and so on. In terms of dynamic performance, the three structures had some similarities. The vehicle stability and comfort index are better under the double-layer structure. And this kind of structure was most affected by the stiffness of the air spring. The damping of vertical dampers had the following effect on the vibration transmissibility of the three structures, which were the greater the damping, the lower the low frequency transmissibility and the higher the high frequency transmissibility. The vertical displacement of the bridge’s midspan fluctuates gradually when a vehicle dynamic load is applied, moving first upward and then downward before exhibiting a wide range of deflection, finally returning to normal. The change of vertical acceleration of the bridge’s midspan caused by the suspension frame of the double-layer structure is the smoothest. The structure of the single-layer frame produces an obviously greater mid-span vertical acceleration than the other two structures. The upward deflection of the bridge increases with the increase of vehicle’s running speed, while the downward deflection of the bridge tends to decrease. The results are all simulation analysis results under specific structural parameters and load conditions, which can provide some reference for the design and selection of the suspension frame structure of HTS maglev train. © 2023, Central South University Press. All rights reserved.