Experimental and Numerical Investigation of the Dynamic Characteristics of an HTS Maglev Scaled Vehicle-Bridge Coupled System

The suspension bogie is crucial for the high-temperature superconducting (HTS) maglev train, providing support, levitation, guidance, traction, braking, and shock absorption. This paper developed a scaled HTS maglev vehicle with full functions based on the train's suspension bogie. Experiments were conducted on a short-distance test line to measure the dynamic response of the vehicle at speeds of 5 m/s, 6 m/s, and 7 m/s. A coupled model of the HTS vehicle-bridge system, accounting for track irregularities, was constructed and validated against experimental data. The model was then used to explore the dynamic response of the vehicle-bridge coupled system under various conditions, identifying key factors affecting the safety and stability of the vehicle and train. This study combines experimental and numerical analyses and found that the vehicle's primary vibration frequency aligns with a single HTS levitator (a heat-insulation device equipped with liquid nitrogen and HTS bulks) under an identical levitation-load ratio. This correspondence confirms the identified frequencies as the natural frequencies of the maglev system. Numerical simulation analysis of the validated model reveals that the redundant HTS levitator configuration on maglev trains substantially optimizes dynamic performance, improving system safety and adaptability to load variations. As speed increases, the scaled vehicle's motion and the HTS levitator's vibration amplitudes rise, with a levitation gap of less than 8 mm at 180 km/h. The track beam's mid-span vertical vibration demonstrates velocity-robust dynamic responses. The vehicle exhibits superior dynamic response on small-span track beams. These findings provide valuable insights for future HTS maglev train dynamic research and structural design.